WO2021008524A1 - 图像编码方法、解码方法、装置和存储介质 - Google Patents

图像编码方法、解码方法、装置和存储介质 Download PDF

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WO2021008524A1
WO2021008524A1 PCT/CN2020/101886 CN2020101886W WO2021008524A1 WO 2021008524 A1 WO2021008524 A1 WO 2021008524A1 CN 2020101886 W CN2020101886 W CN 2020101886W WO 2021008524 A1 WO2021008524 A1 WO 2021008524A1
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image
grid
bits
bit
pixel value
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PCT/CN2020/101886
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English (en)
French (fr)
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林永兵
马莎
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华为技术有限公司
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
    • H04N19/503—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving temporal prediction
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
    • H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
    • H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
    • H04N19/17—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object
    • H04N19/176—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being an image region, e.g. an object the region being a block, e.g. a macroblock

Definitions

  • This application relates to the technical field of image coding and decoding, and more specifically, to an image coding method, decoding method, device, and storage medium.
  • the laser detection and ranging system is a radar system that uses a laser as a radiation source, and can be referred to as LiDAR for short.
  • Lidar is a product of the combination of laser technology and radar technology. Lidar has the characteristics of high detection accuracy, large measurement range, non-contact, 3D and 360-degree measurement. Lidar is often used for high-precision map construction, high-precision positioning, target detection, 3D scene rendering, etc.
  • 3D point cloud data generated by lidar measurement is huge, which brings huge challenges to point cloud data storage and transmission.
  • 3D point cloud data is generally converted into 2D point cloud data as a positioning layer.
  • the bit layer still covers a large geographic area, and the amount of data is still large.
  • the bitstream obtained by image encoding in the point cloud data still consumes a lot of storage overhead.
  • This application provides an image encoding method, decoding method, device, and storage medium to reduce the storage space occupied by the code stream.
  • an image decoding method which includes: obtaining a code stream; obtaining a residual image of a grid image in an image sequence according to the code stream; performing inter-frame prediction on the grid image in the image sequence, Obtain the predicted image of the grid image in the image sequence; obtain the grid image in the image sequence according to the residual image of the grid image in the image sequence and the predicted image of the grid image in the image sequence.
  • the above-mentioned image sequence includes a plurality of grid images, and the geographical locations corresponding to the plurality of grid images are similar or the image contents of the plurality of grid images are similar.
  • that the geographic locations corresponding to the multiple grid images are similar or the image content of the multiple grid images is similar may mean that the multiple grid images satisfy the first condition.
  • inter-prediction of the grid image in the image sequence may be to first predict the grid image to obtain the residual image of the grid image, and then compare the residual image of the grid image and the grid image The image is subtracted to obtain the residual image of the grid image.
  • the grid images in the image sequence may be divided into image blocks first, and then the prediction block of each image block is determined by means of inter-frame prediction. Then determine the residual block of each image block.
  • the predicted image of the aforementioned grid image may be composed of prediction blocks of each image block in the grid image
  • the residual image of the grid image may be composed of residual blocks of each image block in the grid image.
  • the image sequence contains grid images with similar geographic locations or similar image content
  • the amount of residual image data obtained can be made smaller, so that the final The code stream corresponding to the image sequence occupies a small storage space, which is convenient for storage or transmission.
  • the foregoing first condition is that the distance between geographic locations corresponding to at least two grid images in the plurality of grid images is less than a preset distance.
  • the aforementioned preset distance may also become a distance threshold, and the size of the preset distance can be flexibly set according to actual needs.
  • the aforementioned preset distance may be set to 3m (3m).
  • the preset distance can also be set to 5m, 6m, etc. In short, any suitable size preset distance can be set as needed.
  • the foregoing first condition may also be that the distance between the geographic locations corresponding to at least two of the plurality of grid images is less than or equal to a preset distance.
  • the above-mentioned first condition is that the similarity of the image content of at least two grid images in the plurality of grid images is greater than or equal to the preset similarity.
  • the aforementioned preset similarity may also be referred to as a similarity threshold, and the size of the preset similarity can be flexibly set according to actual needs.
  • the aforementioned preset similarity may be set to 50%.
  • the preset similarity can also be set to 55%, 60%, 65%, etc. In short, any suitable size of the preset similarity can be set as needed.
  • the above-mentioned first condition may also be that the similarity of the image content of at least two of the plurality of grid images is greater than the preset similarity.
  • the image sequence contains at least two grid images with similar image content
  • the data amount of the residual image obtained subsequently can be made smaller.
  • the above-mentioned first condition is that the image content of at least two grid images in the plurality of grid images corresponds to the same geographic area.
  • the inter-frame prediction of the image sequence can make the residual image The data amount of the difference image is small.
  • the size of the aforementioned geographic area may be a preset size, and the size of the geographic area may be set according to actual needs.
  • the size of the aforementioned geographic area may be an area of 2m ⁇ 2m. It should be understood that the size of the geographic area of the 2m ⁇ 2m area here is only an example.
  • the size of the geographic area may also be set to an area of 1m ⁇ 1m, an area of 3m ⁇ 32m, etc., in short, any suitable size of geographic area can be set as needed. area.
  • the size of the aforementioned geographic area is an area of 2m ⁇ 2m.
  • the two grid images satisfy the first condition.
  • At least two of the above-mentioned multiple grid images are grid images of adjacent frames between each other.
  • At least two grid images satisfying the first condition are adjacent frames between each other.
  • grid image 1, grid image 2, and grid image 3 in the aforementioned image sequence satisfy the aforementioned first condition.
  • the grid image 1, the grid image 2 and the grid image 3 may be the i-th frame, the i+1-th frame and the i+2-th frame in the image sequence, respectively.
  • i is a positive integer.
  • the pixel value of the grid image in the above image sequence is represented by M bits, and the value of each bit is 0 or 1, and M is an integer greater than 1.
  • the above method further includes: processing the grid image in the image sequence to obtain the processed grid image.
  • the value of the i-th bit among the N bits of the pixel value of the grid image in the image sequence is equal to the value of the i-th bit among the N bits of the pixel value of the grid image in the processed image sequence
  • the position of the N bits of the pixel value of the grid image in the image sequence is the same as the position of the N bits of the pixel value of the grid image in the processed image sequence.
  • the N bits of the pixel value of the grid image in the image sequence are located after and adjacent to the first bit of the pixel value of the grid image in the image sequence.
  • the first bit is the value of the grid image in the image sequence.
  • i and N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoder end by inverting the pixel value of the grid image can reduce the data volume of the grid image when the pixel value of the grid image contains continuous placeholders, thereby making the encoding generation
  • the code stream occupies less storage space, and the decoding end performs (inversion) processing on the decoded grid image, so as to restore the grid image processed (inversion processing) on the encoding end to obtain the final Grid image.
  • the pixel value of the grid image in the above image sequence is represented by M bits, and the value of each bit is 0 or 1, and M is an integer greater than 1.
  • the above method further includes: processing the grid image in the image sequence to obtain the processed grid image.
  • the value of the first bit of the N bits of the grid image in the processed image sequence is opposite to the value of the first bit of the N bits of the grid image in the image sequence.
  • the value of the i+1th bit among the N bits of the grid image in the image sequence is the value of the i+1th bit among the N bits of the grid image in the image sequence and the processed value The result of XORing the i-th bit among the N bits of the grid image in the image sequence.
  • the N bits of the pixel value of the grid image in the image sequence are located after and adjacent to the first bit of the pixel value of the grid image in the image sequence.
  • the first bit is the value of the grid image in the image sequence.
  • the pixel value has a value of 1 and the highest number of bits, or the N bits of the pixel value of the grid image in the image sequence are located after the highest bit of the pixel value of the grid image in the image sequence and are the same as the image
  • the highest bits of the pixel values of the grid images in the sequence are adjacent.
  • the N bits of the pixel value of the grid image in the image sequence are at the same position as the N bits of the pixel value of the grid image in the processed image sequence, and the number of bits of the i-th bit is higher than that of the i+th bit
  • the number of bits of 1 bit, i and N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoding end performs exclusive OR processing on the pixel values of the grid image, so that when the pixel values of the grid image contain continuous placeholders, the data volume of the grid image can be reduced, thereby making the code generated
  • the code stream occupies less storage space
  • the decoder performs (exclusive OR) processing on the decoded grid image, so as to restore the grid image processed (exclusive or processed) on the encoder side to obtain the final Grid image.
  • the pixel value of the above residual image is represented by M bits, and the value of each bit is 0 or 1, and M is an integer greater than 1.
  • the residual image of the grid image in the sequence and the predicted image of the grid image in the image sequence to obtain the grid image in the image sequence specifically includes: processing the residual image to obtain the processed residual image; After the processed residual image and the predicted image of the grid image in the image sequence, the grid image in the image sequence is obtained.
  • the value of the i-th bit among the N bits of the pixel value of the residual image is opposite to the value of the i-th bit among the N bits of the pixel value of the residual image after processing.
  • the N bits of the pixel value of the image are at the same positions as the N bits of the pixel value of the processed residual image.
  • the N bits of the pixel value of the residual image are located after and adjacent to the first bit of the pixel value of the residual image.
  • the first bit is the pixel value of the residual image with the value 1 and the highest number of bits.
  • Bit position, i and N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoding end by inverting the pixel value of the residual image can reduce the amount of data of the residual image when the pixel value of the residual image contains continuous placeholders, thereby making the code generated
  • the code stream occupies less storage space, and the decoder can restore the residual image processed (inverted) by the encoding end by (inverting) the decoded residual image, and then according to the processing After the residual image gets the final image block.
  • the pixel value of the above residual image is represented by M bits, and the value of each bit is 0 or 1, and M is an integer greater than 1.
  • the residual image of the grid image in the sequence and the predicted image of the grid image in the image sequence to obtain the grid image in the image sequence includes: processing the residual image to obtain the processed residual image; After the residual image and the predicted image of the grid image in the image sequence, the grid image in the image sequence is obtained.
  • the value of the first bit of the N bits of the residual image after the above processing is opposite to the value of the first bit of the N bits of the residual image, and the N bits of the processed residual image
  • the value of the i+1th bit in the bits is that the value of the i+1th bit in the N bits of the residual image is different from the i-th bit in the N bits of the processed residual image. Or the result of processing.
  • the N bits of the pixel value of the residual image are located after and adjacent to the first bit of the pixel value of the residual image.
  • the first bit is the pixel value of the residual image with the value 1 and the highest number of bits.
  • the bit position, or, the N bits of the pixel value of the residual image are located after the highest bit of the pixel value of the residual image and adjacent to the highest bit of the pixel value of the residual image.
  • the N bits of the pixel value of the residual image are at the same position as the N bits of the pixel value of the processed residual image.
  • the number of bits of the i-th bit is higher than that of the i+1th bit, i And N are both positive integers, i ⁇ N, N ⁇ M;
  • the encoding end performs XOR processing on the pixel values of the residual image, so that when the pixel values of the residual image contain continuous placeholders, the data volume of the residual image can be reduced, so that the encoded
  • the code stream occupies less storage space
  • the decoding end performs (exclusive OR) processing on the decoded residual image, so as to restore the residual image processed (exclusive or processed) by the encoding end, and then according to the processing After the residual image gets the final image block.
  • the above-mentioned obtaining the residual image of the grid image in the image sequence according to the code stream includes: performing inverse transformation, inverse quantization and entropy decoding processing on the code stream, Get the residual image.
  • the above-mentioned decoding processing corresponds to the lossy encoding of the image, which can make the code stream obtained by encoding occupy as little storage space as possible.
  • the foregoing obtaining the residual image of the grid image in the image sequence according to the code stream includes: performing entropy decoding processing on the code stream to obtain the residual image.
  • the foregoing decoding method that only performs entropy decoding processing corresponds to lossless encoding.
  • This encoding method can avoid image distortion as much as possible and ensure the final display effect of the image.
  • the above code stream is obtained by encoding the positioning layer.
  • the pixel value of the positioning layer includes rasterized elevation data.
  • the pixel value of the above positioning layer contains M bits, and each bit represents the occupied position of each grid. Since the pixel value of the positioning layer contains the rasterized elevation data, and the character "11" in the high position of the elevation data has a higher probability, the pixel value of the positioning layer containing the elevation data can be processed. Reduce the data volume of the pixel value of the positioning layer, thereby reducing the storage space occupied by the finally obtained code stream.
  • the value of M above is any one of 8, 10, and 12.
  • an image encoding method which includes: acquiring an image sequence; performing inter-frame prediction on grid images in the image sequence to obtain a residual image; and encoding the residual image to obtain an encoded bitstream.
  • the above-mentioned image sequence includes a plurality of grid images, and the geographical locations corresponding to the plurality of grid images are similar or the image contents of the plurality of grid images are similar.
  • that the geographic locations corresponding to the multiple grid images are similar or the image content of the multiple grid images is similar may mean that the multiple grid images satisfy the first condition.
  • inter-prediction of the grid image in the image sequence may be to first predict the grid image to obtain the residual image of the grid image, and then compare the residual image of the grid image and the grid image The image is subtracted to obtain the residual image of the grid image.
  • the predicted image of the grid image may be composed of prediction blocks of each image block in the grid image
  • the residual image of the grid image may be composed of residual blocks of each image block in the grid image.
  • the residual image can be divided into image blocks, and then the prediction block of each image block is obtained, and the residual block of each image block is obtained according to each image block and the residual block of each image block. Difference block, and then obtain the residual image of the grid image.
  • the image sequence contains grid images with similar geographic locations or similar image content
  • the amount of residual image data obtained can be made smaller, so that the final The code stream obtained by encoding the image sequence occupies a small storage space, which is convenient for storage or transmission.
  • the foregoing first condition is that the distance between the geographic locations corresponding to at least two of the plurality of grid images is less than a preset distance.
  • the aforementioned preset distance may also become a distance threshold, and the size of the preset distance can be flexibly set according to actual needs.
  • the aforementioned preset distance may be set to 3m (3m).
  • the preset distance can also be set to 5m, 6m, etc. In short, any suitable size preset distance can be set as needed.
  • the foregoing first condition may also be that the distance between the geographic locations corresponding to at least two of the plurality of grid images is less than or equal to a preset distance.
  • the above-mentioned first condition is that the similarity of the image content of at least two grid images in the plurality of grid images is greater than or equal to a preset similarity.
  • the image sequence contains at least two grid images with similar image content
  • the data amount of the residual image obtained subsequently can be made smaller.
  • the aforementioned preset similarity may also be referred to as a similarity threshold, and the size of the preset similarity can be flexibly set according to actual needs.
  • the aforementioned preset similarity may be set to 50%.
  • the similarity of the image content of the two grid images is greater than or equal to 50%, the two grid images satisfy the first condition.
  • the 50% here is just an example, the preset similarity can also be set to 55%, 60%, 65%, etc. In short, any suitable size of the preset similarity can be set as needed.
  • the above-mentioned first condition may also be that the similarity of the image content of at least two of the plurality of grid images is greater than the preset similarity.
  • the image sequence contains at least two grid images with similar image content
  • the data amount of the residual image obtained subsequently can be made smaller.
  • the above-mentioned first condition is that the image content of at least two grid images in the image sequence corresponds to the same geographic area.
  • the inter-frame prediction of the image sequence can make the residual image The data amount of the difference image is small.
  • the size of the aforementioned geographic area may be a preset size, and the size of the geographic area may be set according to actual needs.
  • the size of the aforementioned geographic area may be an area of 2m ⁇ 2m. It should be understood that the size of the geographic area of the 2m ⁇ 2m area here is only an example.
  • the size of the geographic area may also be set to an area of 1m ⁇ 1m, an area of 3m ⁇ 32m, etc., in short, any suitable size of geographic area can be set as needed. area.
  • the size of the aforementioned geographic area is an area of 2m ⁇ 2m.
  • the two grid images satisfy the first condition.
  • At least two grid images in the plurality of grid images are grid images of adjacent frames with each other.
  • the at least two grid images satisfying the first condition may be adjacent frames to each other.
  • grid image 1, grid image 2, and grid image 3 in the aforementioned image sequence satisfy the aforementioned first condition.
  • the grid image 1, the grid image 2 and the grid image 3 may be the i-th frame, the i+1-th frame and the i+2-th frame in the image sequence, respectively.
  • i is a positive integer.
  • the pixel value of the grid image in the image sequence is represented by M bits, and the value of each bit is 0 or 1, and M is an integer greater than 1,
  • the above method further includes: processing the grid images in the image sequence to obtain a processed grid image; performing inter-frame on the grid images in the image sequence Prediction includes: performing inter-frame prediction on the processed grid image to obtain a residual image.
  • the value of the i-th bit among the N bits of the pixel value of the grid image in the image sequence is equal to the value of the i-th bit among the N bits of the pixel value of the grid image in the processed image sequence
  • the position of the N bits of the pixel value of the grid image in the image sequence is the same as the position of the N bits of the pixel value of the grid image in the processed image sequence.
  • the N bits of the pixel value of the grid image in the image sequence are located after and adjacent to the first bit of the pixel value of the grid image in the image sequence.
  • the first bit is the value of the grid image in the image sequence.
  • i and N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoding end uses the inverse processing of the pixel values of the grid image to reduce the data volume of the grid image when the pixel value of the grid image contains continuous placeholders, thereby making the code generated
  • the code stream takes up less storage space.
  • the pixel value of the grid image in the image sequence is represented by M bits, and the value of each bit is 0 or 1, and M is an integer greater than 1,
  • the above method further includes: processing the grid images in the image sequence to obtain a processed grid image; performing inter-frame on the grid images in the image sequence Prediction includes: performing inter-frame prediction on the processed grid image to obtain a residual image.
  • the value of the first bit of the N bits of the grid image in the processed image sequence is opposite to the value of the first bit of the N bits of the grid image in the image sequence.
  • the value of the i+1th bit among the N bits of the grid image in the image sequence is the value of the i+1th bit among the N bits of the grid image in the image sequence and the processed value The result of XORing the i-th bit among the N bits of the grid image in the image sequence.
  • the N bits of the pixel value of the grid image in the image sequence are located after and adjacent to the first bit of the pixel value of the grid image in the image sequence.
  • the first bit is the value of the grid image in the image sequence.
  • the pixel value has a value of 1 and the highest number of bits, or the N bits of the pixel value of the grid image in the image sequence are located after the highest bit of the pixel value of the grid image in the image sequence and are the same as the image
  • the highest bits of the pixel values of the grid images in the sequence are adjacent.
  • the N bits of the pixel value of the grid image in the image sequence are at the same position as the N bits of the pixel value of the grid image in the processed image sequence, and the number of bits of the i-th bit is higher than that of the i+th bit
  • the number of bits of 1 bit, i and N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoding end performs exclusive OR processing on the pixel values of the grid image, so that when the pixel values of the grid image contain continuous placeholders, the data volume of the grid image can be reduced, thereby making the code generated
  • the code stream takes up less storage space.
  • the pixel value of the residual image is represented by M bits, and the value of each bit is 0 or 1, and M is an integer greater than 1, characterized in that:
  • the foregoing encoding the residual image to obtain an encoded bitstream includes: processing the residual image to obtain a processed residual image; and encoding the processed residual image to obtain an encoded bitstream.
  • the value of the i-th bit among the N bits of the pixel value of the residual image is opposite to the value of the i-th bit among the N bits of the pixel value of the residual image after processing.
  • the residual image The N bits of the pixel value of, and the N bits of the pixel value of the processed residual image are at the same position,
  • the N bits of the pixel value of the residual image are located after and adjacent to the first bit of the pixel value of the residual image.
  • the first bit is the pixel value of the residual image with the value 1 and the highest number of bits.
  • Bit position, i and N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoding end performs XOR processing on the pixel values of the residual image, so that when the pixel values of the residual image contain continuous placeholders, the data amount of the residual image can be reduced, thereby enabling the encoding
  • the generated code stream takes up less storage space.
  • the pixel value of the residual image is represented by M bits, and the value of each bit is 0 or 1, and M is an integer greater than 1, characterized in that:
  • the foregoing encoding the residual image to obtain an encoded bitstream includes: processing the residual image to obtain a processed residual image; and encoding the processed residual image to obtain an encoded bitstream.
  • the value of the i-th bit among the N bits of the pixel value of the residual image is opposite to the value of the i-th bit among the N bits of the pixel value of the residual image after processing.
  • the value of the i+1th bit among the N bits of the difference image is the value of the i+1th bit among the N bits of the residual image and the value of the N bits of the processed residual image.
  • the N bits of the pixel value of the residual image are located after and adjacent to the first bit of the pixel value of the residual image.
  • the first bit is the pixel value of the residual image with the value 1 and the highest number of bits.
  • the bit position, or, the N bits of the pixel value of the residual image are located after the highest bit of the pixel value of the residual image and adjacent to the highest bit of the pixel value of the residual image.
  • the N bits of the pixel value of the residual image are at the same position as the N bits of the pixel value of the processed residual image.
  • the number of bits of the i-th bit is higher than that of the i+1th bit, i And N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoding end performs XOR processing on the pixel values of the residual image, so that when the pixel values of the residual image contain continuous placeholders, the data amount of the residual image can be reduced, thereby enabling the encoding
  • the generated code stream takes up less storage space.
  • encoding the residual image to obtain an encoded bitstream includes: performing transformation, quantization, and entropy encoding processing on the residual image to obtain an encoded bitstream.
  • the code stream obtained by encoding can occupy as little storage space as possible.
  • encoding the residual image to obtain an encoded bitstream includes: performing entropy encoding processing on the residual image to obtain an encoded bitstream.
  • the grid pictures in the above-mentioned image sequence come from a positioning layer.
  • the pixel values of the positioning layer include rasterized elevation data.
  • the pixel value of the above positioning layer contains M bits, and each bit represents the occupied position of each grid. Since the pixel value of the positioning layer contains the rasterized elevation data, and the character "11" in the high position of the elevation data has a higher probability, the pixel value of the positioning layer containing the elevation data can be processed. Reduce the data volume of the pixel value of the positioning layer, thereby reducing the storage space occupied by the finally obtained code stream.
  • the value of M is any one of 8, 10, and 12.
  • an image decoding device which includes a module corresponding to the method of the first aspect described above, and the corresponding module can implement each step of the method of the first aspect described above.
  • an image encoding device which includes a module corresponding to the method of the second aspect described above, and the corresponding module can implement each step of the method of the second aspect described above.
  • the image decoding device in the foregoing third aspect or the image encoding device in the foregoing fourth aspect may include one or more modules, and any one of the one or more modules may be composed of a circuit, a field programmable gate array FPGA, and a special Any one of the application integrated circuit ASIC and general processor.
  • an image decoding device including a memory and a processor, and the processor calls the program code stored in the memory to execute the method of the first aspect.
  • an image encoding device including a memory and a processor, and the processor calls the program code stored in the memory to execute the method of the second aspect.
  • the aforementioned memory is a non-volatile memory.
  • the foregoing memory and the processor are coupled with each other.
  • the image decoding device described above may also be referred to as an image decoder, and the image encoding device described above may also be referred to as an image encoder.
  • embodiments of the present application provide a computer-readable storage medium that stores instructions that cause one or more processors to execute the method in the first aspect or the second aspect.
  • Any one of the above one or more processors may be composed of any one of a circuit, a field programmable gate array FPGA, a special application integrated circuit ASIC, and a general-purpose processor.
  • the embodiments of the present application provide a computer program product that, when the computer program product runs on a computer, causes the computer to execute part or all of the steps of the method in the first aspect or the second aspect.
  • FIG. 1 is a schematic block diagram of an example of a video encoding system used to implement an embodiment of the present application
  • Fig. 2 is a schematic structural block diagram of an example of a video encoder used to implement an embodiment of the present application
  • Fig. 3 is a schematic structural block diagram of an example of a video decoder used to implement an embodiment of the present application
  • FIG. 4 is a schematic structural block diagram of an example of a video decoding system used to implement an embodiment of the present application
  • FIG. 5 is a schematic structural block diagram of an example of a video decoding device used to implement an embodiment of the present application
  • FIG. 6 is a schematic block diagram of an example of an encoding device or a decoding device used to implement an embodiment of the present application
  • FIG. 7 is a schematic diagram of candidate motion information of the current coding unit in spatial and temporal domains
  • FIG. 8 is a schematic diagram of a process of an image coding method according to an embodiment of the present application.
  • FIG. 9 is a schematic diagram of a process of an image coding method according to an embodiment of the present application.
  • FIG. 10 is a schematic diagram of a process of an image coding method according to an embodiment of the present application.
  • FIG. 11 is a schematic flowchart of an image decoding method according to an embodiment of the present application.
  • FIG. 12 is a schematic flowchart of an image decoding method according to an embodiment of the present application.
  • FIG. 13 is a schematic flowchart of an image decoding method according to an embodiment of the present application.
  • FIG. 14 is a schematic flowchart of an image coding method according to an embodiment of the present application.
  • FIG. 15 is a schematic flowchart of an image coding method according to an embodiment of the present application.
  • FIG. 16 is a schematic diagram of the encoding performance corresponding to the inversion operation
  • FIG. 17 is a schematic diagram of encoding performance corresponding to an exclusive OR operation
  • FIG. 18 is a schematic flowchart of an image coding method according to an embodiment of the present application.
  • Figure 19 is a schematic diagram of an image sequence including I frames and P frames
  • FIG. 20 is a schematic diagram of converting 3D point cloud data into 2D plane data
  • FIG. 21 is a schematic block diagram of an image decoding device according to an embodiment of the present application.
  • FIG. 22 is a schematic block diagram of an image encoding device according to an embodiment of the present application.
  • FIG. 23 is a schematic block diagram of an image decoding device according to an embodiment of the present application.
  • FIG. 24 is a schematic block diagram of an image encoding device according to an embodiment of the present application.
  • the corresponding device may include one or more units such as functional units to perform the described one or more method steps (for example, one unit performs one or more Steps, or multiple units, each of which performs one or more of the multiple steps), even if such one or more units are not explicitly described or illustrated in the drawings.
  • the corresponding method may include one step to perform the functions of one or more units (for example, one step performs the functions of one or more units, or more Steps, each of which performs the function of one or more of the multiple units), even if such one or more steps are not explicitly described or illustrated in the drawings.
  • one step performs the functions of one or more units, or more Steps, each of which performs the function of one or more of the multiple units
  • the features of the exemplary embodiments and/or aspects described herein can be combined with each other.
  • the image encoding and decoding in this application are the same as the encoding and decoding of video images. Some basic processes and related content of the encoding and decoding of video images are described in detail below.
  • Video coding generally refers to processing a sequence of pictures that form a video or video sequence.
  • the terms "picture”, "frame” or “image” can be used as synonyms.
  • Video encoding used in this article means video encoding or video decoding.
  • Video encoding is performed on the source side and usually includes processing (for example, by compressing) the original video picture to reduce the amount of data required to represent the video picture, so as to store and/or transmit more efficiently.
  • Video decoding is performed on the destination side and usually involves inverse processing relative to the encoder to reconstruct the video picture.
  • the “encoding” of video pictures involved in the embodiments should be understood as involving “encoding” or “decoding” of a video sequence.
  • the combination of the encoding part and the decoding part is also called codec (encoding and decoding).
  • a video sequence includes a series of pictures, the pictures are further divided into slices, and the slices are divided into blocks.
  • Video coding is performed in units of blocks.
  • the concept of blocks is further expanded.
  • MB macroblock
  • the macroblock can be further divided into multiple prediction blocks (partitions) that can be used for predictive coding.
  • HEVC high efficiency video coding
  • basic concepts such as coding unit (CU), prediction unit (PU), and transform unit (TU) are adopted.
  • CU coding unit
  • PU prediction unit
  • TU transform unit
  • a variety of block units are divided, and a new tree-based structure is used for description.
  • the CU can be divided into smaller CUs according to the quadtree, and the smaller CUs can be further divided to form a quadtree structure.
  • the CU is a basic unit for dividing and encoding the coded image.
  • PU can correspond to prediction block and is the basic unit of prediction coding.
  • the CU is further divided into multiple PUs according to the division mode.
  • the TU can correspond to the transform block and is the basic unit for transforming the prediction residual.
  • no matter CU, PU or TU they all belong to the concept of block (or image block) in nature.
  • a CTU is split into multiple CUs by using a quadtree structure represented as a coding tree.
  • a decision is made at the CU level whether to use inter-picture (temporal) or intra-picture (spatial) prediction to encode picture regions.
  • Each CU can be further split into one, two or four PUs according to the PU split type.
  • the same prediction process is applied in a PU, and relevant information is transmitted to the decoder on the basis of the PU.
  • the CU may be divided into transform units (TU) according to other quadtree structures similar to the coding tree used for the CU.
  • quad-tree and binary tree quad-tree and binary tree (quad-tree and binary tree, QTBT) are used to divide frames to divide coding blocks.
  • the CU may have a square or rectangular shape.
  • the image block to be encoded in the currently encoded image may be referred to as the current image block.
  • a reference block is a block that provides a reference signal for the current image block, where the reference signal represents the pixel value in the image block.
  • the block in the reference image that provides the prediction signal for the current image block may be the prediction block, where the prediction signal represents the pixel value or sample value or sample signal in the prediction block. For example, after traversing multiple reference blocks, the best reference block is found. This best reference block will provide prediction for the current image block, and this block is called a prediction block.
  • the original video picture can be reconstructed, that is, the reconstructed video picture has the same quality as the original video picture (assuming no transmission loss or other data loss during storage or transmission).
  • quantization is performed to perform further compression to reduce the amount of data required to represent the video picture, and the decoder side cannot completely reconstruct the video picture, that is, the quality of the reconstructed video picture is compared with the original video picture The quality is low or poor.
  • Video coding standards of H.261 belong to "lossy hybrid video coding and decoding” (that is, combining spatial and temporal prediction in the sample domain with 2D transform coding for applying quantization in the transform domain).
  • Each picture of a video sequence is usually divided into a set of non-overlapping blocks, and is usually coded at the block level.
  • the encoder side usually processes at the block (video block) level, that is, encodes the video.
  • the prediction block is generated by spatial (intra-picture) prediction and temporal (inter-picture) prediction, from the current image block (current processing or The block to be processed) is subtracted from the prediction block to obtain the residual block, the residual block is transformed in the transform domain and the residual block is quantized to reduce the amount of data to be transmitted (compressed), and the decoder side will be inverse to the encoder
  • the processing part is applied to the coded or compressed block to reconstruct the current image block for representation.
  • the encoder duplicates the decoder processing loop, so that the encoder and the decoder generate the same prediction (for example, intra prediction and inter prediction) and/or reconstruction for processing, that is, to encode subsequent blocks.
  • FIG. 1 exemplarily shows a schematic block diagram of a video encoding and decoding system 10 applied in an embodiment of the present application.
  • the video encoding and decoding system 10 may include a source device 12 and a destination device 14.
  • the source device 12 generates encoded video data. Therefore, the source device 12 may be referred to as a video encoding device.
  • the destination device 14 can decode the encoded video data generated by the source device 12, and therefore, the destination device 14 can be referred to as a video decoding device.
  • Various implementations of source device 12, destination device 14, or both may include one or more processors and memory coupled to the one or more processors.
  • the memory may include, but is not limited to, read-only memory (ROM), random access memory (RAM), erasable programmable read-only memory (EPROM) , Flash memory, or any other medium that can be used to store the desired program code in the form of instructions or data structures that can be accessed by a computer, as described herein.
  • the source device 12 and the destination device 14 may include various devices, including desktop computers, mobile computing devices, notebook (for example, laptop) computers, tablet computers, set-top boxes, telephone handsets such as so-called "smart" phones. Computers, televisions, cameras, display devices, digital media players, video game consoles, on-board computers, wireless communication equipment, or the like.
  • FIG. 1 shows the source device 12 and the destination device 14 as separate devices
  • the device embodiment may also include the source device 12 and the destination device 14 or the functions of both, that is, the source device 12 or the corresponding Function and destination device 14 or corresponding function.
  • the same hardware and/or software may be used, or separate hardware and/or software, or any combination thereof may be used to implement the source device 12 or the corresponding functionality and the destination device 14 or the corresponding functionality .
  • the source device 12 and the destination device 14 may communicate with each other via a link 13, and the destination device 14 may receive encoded video data from the source device 12 via the link 13.
  • Link 13 may include one or more media or devices capable of moving encoded video data from source device 12 to destination device 14.
  • link 13 may include one or more communication media that enable source device 12 to transmit encoded video data directly to destination device 14 in real time.
  • the source device 12 may modulate the encoded video data according to a communication standard, such as a wireless communication protocol, and may transmit the modulated video data to the destination device 14.
  • the one or more communication media may include wireless and/or wired communication media, such as a radio frequency (RF) spectrum or one or more physical transmission lines.
  • RF radio frequency
  • the one or more communication media may form part of a packet-based network, such as a local area network, a wide area network, or a global network (e.g., the Internet).
  • the one or more communication media may include routers, switches, base stations, or other devices that facilitate communication from source device 12 to destination device 14.
  • the source device 12 includes an encoder 20, and optionally, the source device 12 may also include a picture source 16, a picture preprocessor 18, and a communication interface 22.
  • the encoder 20, the picture source 16, the picture preprocessor 18, and the communication interface 22 may be hardware components in the source device 12, or may be software programs in the source device 12. They are described as follows:
  • the picture source 16 which can include or can be any type of picture capture device, for example to capture real-world pictures, and/or any type of pictures or comments (for screen content encoding, some text on the screen is also considered to be encoded Picture or part of an image) generating equipment, for example, a computer graphics processor for generating computer animation pictures, or for obtaining and/or providing real world pictures, computer animation pictures (for example, screen content, virtual reality, VR) pictures), and/or any combination thereof (for example, augmented reality (AR) pictures).
  • the picture source 16 may be a camera for capturing pictures or a memory for storing pictures.
  • the picture source 16 may also include any type of (internal or external) interface for storing previously captured or generated pictures and/or acquiring or receiving pictures.
  • the picture source 16 When the picture source 16 is a camera, the picture source 16 may be, for example, a local or an integrated camera integrated in the source device; when the picture source 16 is a memory, the picture source 16 may be local or, for example, an integrated camera integrated in the source device. Memory.
  • the interface When the picture source 16 includes an interface, the interface may be, for example, an external interface for receiving pictures from an external video source.
  • the external video source is, for example, an external picture capturing device, such as a camera, an external memory, or an external picture generating device, such as It is an external computer graphics processor, computer or server.
  • the interface can be any type of interface according to any proprietary or standardized interface protocol, such as a wired or wireless interface, and an optical interface.
  • a picture can be regarded as a two-dimensional array or matrix of picture elements.
  • the pixel points in the array can also be called sampling points.
  • the number of sampling points of the array or picture in the horizontal and vertical directions (or axis) defines the size and/or resolution of the picture.
  • three color components are usually used, that is, pictures can be represented as or contain three sample arrays.
  • a picture includes corresponding red, green, and blue sample arrays.
  • each pixel is usually expressed in a luminance/chrominance format or color space.
  • a picture in the YUV format includes the luminance component indicated by Y (sometimes indicated by L) and the two indicated by U and V. Chrominance components.
  • the luma component Y represents brightness or gray level intensity (for example, the two are the same in a grayscale picture), and the two chroma components U and V represent chroma or color information components.
  • a picture in the YUV format includes a luminance sample array of luminance sample values (Y), and two chrominance sample arrays of chrominance values (U and V).
  • Pictures in RGB format can be converted or converted to YUV format, and vice versa. This process is also called color conversion or conversion. If the picture is black and white, the picture may only include the luminance sample array.
  • the picture transmitted from the picture source 16 to the picture processor may also be referred to as original picture data 17.
  • the picture preprocessor 18 is configured to receive the original picture data 17 and perform preprocessing on the original picture data 17 to obtain the preprocessed picture 19 or the preprocessed picture data 19.
  • the pre-processing performed by the picture pre-processor 18 may include trimming, color format conversion (for example, conversion from RGB format to YUV format), toning, or denoising.
  • the encoder 20 (or video encoder 20) is configured to receive the pre-processed picture data 19, and process the pre-processed picture data 19 using a relevant prediction mode (such as the prediction mode in the various embodiments herein), thereby
  • the encoded picture data 21 is provided (the structure details of the encoder 20 will be described further based on FIG. 2 or FIG. 4 or FIG. 5).
  • the encoder 20 may be used to implement the various embodiments described below to realize the application of the encoding method described in this application on the encoding side.
  • the communication interface 22 can be used to receive the encoded picture data 21, and can transmit the encoded picture data 21 to the destination device 14 or any other device (such as a memory) via the link 13 for storage or direct reconstruction, so The other device can be any device used for decoding or storage.
  • the communication interface 22 can be used, for example, to encapsulate the encoded picture data 21 into a suitable format, such as a data packet, for transmission on the link 13.
  • the destination device 14 includes a decoder 30, and optionally, the destination device 14 may also include a communication interface 28, a picture post processor 32, and a display device 34. They are described as follows:
  • the communication interface 28 may be used to receive the encoded picture data 21 from the source device 12 or any other source, for example, a storage device, and the storage device is, for example, an encoded picture data storage device.
  • the communication interface 28 can be used to transmit or receive the encoded picture data 21 through the link 13 between the source device 12 and the destination device 14 or via any type of network.
  • the link 13 is, for example, a direct wired or wireless connection, of any type.
  • the network of is, for example, a wired or wireless network or any combination thereof, or any type of private network and public network, or any combination thereof.
  • the communication interface 28 may be used, for example, to decapsulate the data packet transmitted by the communication interface 22 to obtain the encoded picture data 21.
  • Both the communication interface 28 and the communication interface 22 can be configured as a one-way communication interface or a two-way communication interface, and can be used, for example, to send and receive messages to establish connections, confirm and exchange any other communication links and/or, for example, encoded picture data Information about the transmission of the transmitted data.
  • the decoder 30 (or referred to as the decoder 30) is used to receive the encoded picture data 21 and provide the decoded picture data 31 or the decoded picture 31 (below will further describe the decoder 30 based on Figure 3 or Figure 4 or Figure 5 Structural details).
  • the decoder 30 may be used to implement the various embodiments described below to implement the application of the decoding method described in this application on the decoding side.
  • the picture post processor 32 is configured to perform post-processing on the decoded picture data 31 (also referred to as reconstructed picture data) to obtain post-processed picture data 33.
  • the post-processing performed by the picture post-processor 32 may include: color format conversion (for example, conversion from YUV format to RGB format), toning, trimming or resampling, or any other processing, and can also be used to convert post-processed picture data 33 is transmitted to the display device 34.
  • the display device 34 is configured to receive the post-processed image data 33 to display the image to, for example, users or viewers.
  • the display device 34 may be or may include any type of display for presenting reconstructed pictures, for example, an integrated or external display or monitor.
  • the display may include a liquid crystal display (LCD), an organic light emitting diode (OLED) display, a plasma display, a projector, a micro LED display, a liquid crystal on silicon (LCoS), Digital light processor (digital light processor, DLP) or any other type of display.
  • the device embodiment may also include the source device 12 and the destination device 14 or the functionality of both, that is, the source device 12 Or the corresponding functionality and the destination device 14 or the corresponding functionality.
  • the same hardware and/or software may be used, or separate hardware and/or software, or any combination thereof may be used to implement the source device 12 or the corresponding functionality and the destination device 14 or the corresponding functionality .
  • the source device 12 and the destination device 14 may include any of a variety of devices, including any type of handheld or stationary device, for example, a notebook or laptop computer, mobile phone, smart phone, tablet or tablet computer, video camera, desktop Computers, set-top boxes, televisions, cameras, in-vehicle devices, display devices, digital media players, video game consoles, video streaming devices (such as content service servers or content distribution servers), broadcast receiver devices, broadcast transmitter devices And so on, and can not use or use any type of operating system.
  • a notebook or laptop computer mobile phone, smart phone, tablet or tablet computer
  • video camera desktop Computers
  • set-top boxes televisions, cameras, in-vehicle devices, display devices, digital media players, video game consoles, video streaming devices (such as content service servers or content distribution servers), broadcast receiver devices, broadcast transmitter devices And so on, and can not use or use any type of operating system.
  • Both the encoder 20 and the decoder 30 can be implemented as any of various suitable circuits, for example, one or more microprocessors, digital signal processors (digital signal processors, DSP), and application-specific integrated circuits (application-specific integrated circuits). circuit, ASIC), field-programmable gate array (FPGA), discrete logic, hardware, or any combination thereof.
  • the device can store the instructions of the software in a suitable non-transitory computer-readable storage medium, and can use one or more processors to execute the instructions in hardware to execute the technology of the present application . Any of the foregoing (including hardware, software, a combination of hardware and software, etc.) can be regarded as one or more processors.
  • the video encoding and decoding system 10 shown in FIG. 1 is only an example, and the technology of this application can be applied to video encoding settings that do not necessarily include any data communication between encoding and decoding devices (for example, video encoding or video encoding). decoding).
  • the data can be retrieved from local storage, streamed on the network, etc.
  • the video encoding device can encode data and store the data to the memory, and/or the video decoding device can retrieve the data from the memory and decode the data.
  • encoding and decoding are performed by devices that do not communicate with each other but only encode data to the memory and/or retrieve data from the memory and decode the data.
  • Fig. 2 shows a schematic/conceptual block diagram of an example of an encoder 20 for implementing an embodiment of the present application.
  • the encoder 20 includes a residual calculation unit 204, a transformation processing unit 206, a quantization unit 208, an inverse quantization unit 210, an inverse transformation processing unit 212, a reconstruction unit 214, a buffer 216, and a loop filter.
  • Unit 220 a decoded picture buffer (DPB) 230, a prediction processing unit 260, and an entropy coding unit 270.
  • the prediction processing unit 260 may include an inter prediction unit 244, an intra prediction unit 254, and a mode selection unit 262.
  • the inter prediction unit 244 may include a motion estimation unit and a motion compensation unit (not shown in the figure).
  • the encoder 20 shown in FIG. 2 may also be referred to as a hybrid video encoder or a video encoder according to a hybrid video codec.
  • the residual calculation unit 204, the transform processing unit 206, the quantization unit 208, the prediction processing unit 260, and the entropy encoding unit 270 form the forward signal path of the encoder 20, and for example, the inverse quantization unit 210, the inverse transform processing unit 212, and the The structure unit 214, the buffer 216, the loop filter 220, the decoded picture buffer (DPB) 230, and the prediction processing unit 260 form the backward signal path of the encoder, wherein the backward signal path of the encoder corresponds to The signal path of the decoder (see decoder 30 in FIG. 3).
  • the encoder 20 receives the picture 201 or the image block 203 of the picture 201 through, for example, an input 202, for example, a picture in a picture sequence that forms a video or a video sequence.
  • the image block 203 may also be called the current picture block or the picture block to be encoded
  • the picture 201 may be called the current picture or the picture to be encoded (especially when the current picture is distinguished from other pictures in video encoding, the other pictures are for example the same video sequence). That is, the previous coded and/or decoded picture in the video sequence that also includes the current picture).
  • the embodiment of the encoder 20 may include a segmentation unit (not shown in FIG. 2) for segmenting the picture 201 into a plurality of blocks such as the image block 203, usually into a plurality of non-overlapping blocks.
  • the segmentation unit can be used to use the same block size and the corresponding grid defining the block size for all pictures in the video sequence, or to change the block size between pictures or subsets or groups of pictures, and divide each picture into The corresponding block.
  • the prediction processing unit 260 of the encoder 20 may be used to perform any combination of the aforementioned segmentation techniques.
  • the image block 203 is also or can be regarded as a two-dimensional array or matrix of sampling points with sample values, although its size is smaller than that of the picture 201.
  • the image block 203 may include, for example, one sampling array (for example, a luminance array in the case of a black-and-white picture 201) or three sampling arrays (for example, one luminance array and two chrominance arrays in the case of a color picture) or Any other number and/or type of array depending on the color format applied.
  • the number of sampling points in the horizontal and vertical directions (or axes) of the image block 203 defines the size of the image block 203.
  • the encoder 20 shown in FIG. 2 is used to encode the picture 201 block by block, for example, to perform encoding and prediction on each image block 203.
  • the residual calculation unit 204 is configured to calculate the residual block 205 based on the picture image block 203 and the prediction block 265 (other details of the prediction block 265 are provided below), for example, by subtracting the sample value of the picture image block 203 sample by sample (pixel by pixel). The sample value of the block 265 is de-predicted to obtain the residual block 205 in the sample domain.
  • the transform processing unit 206 is configured to apply a transform such as discrete cosine transform (DCT) or discrete sine transform (DST) on the sample values of the residual block 205 to obtain transform coefficients 207 in the transform domain.
  • a transform such as discrete cosine transform (DCT) or discrete sine transform (DST)
  • DCT discrete cosine transform
  • DST discrete sine transform
  • the transform coefficient 207 may also be referred to as a transform residual coefficient, and represents the residual block 205 in the transform domain.
  • the transform processing unit 206 may be used to apply an integer approximation of DCT/DST, such as the transform specified for HEVC/H.265. Compared with the orthogonal DCT transform, this integer approximation is usually scaled by a factor. In order to maintain the norm of the residual block processed by the forward and inverse transformation, an additional scaling factor is applied as part of the transformation process.
  • the scaling factor is usually selected based on certain constraints. For example, the scaling factor is a trade-off between the power of 2 used for the shift operation, the bit depth of the transform coefficient, accuracy, and implementation cost.
  • the inverse transformation processing unit 212 for the inverse transformation designate a specific scaling factor, and accordingly, the encoder The 20 side uses the transformation processing unit 206 to specify a corresponding scaling factor for the positive transformation.
  • the quantization unit 208 is used to quantize the transform coefficient 207 by applying scalar quantization or vector quantization, for example, to obtain the quantized transform coefficient 209.
  • the quantized transform coefficient 209 may also be referred to as a quantized residual coefficient 209.
  • the quantization process can reduce the bit depth associated with some or all of the transform coefficients 207. For example, n-bit transform coefficients can be rounded down to m-bit transform coefficients during quantization, where n is greater than m.
  • the degree of quantization can be modified by adjusting the quantization parameter (QP). For example, for scalar quantization, different scales can be applied to achieve finer or coarser quantization.
  • QP quantization parameter
  • a smaller quantization step size corresponds to a finer quantization
  • a larger quantization step size corresponds to a coarser quantization.
  • the appropriate quantization step size can be indicated by a quantization parameter (QP).
  • the quantization parameter may be an index of a predefined set of suitable quantization steps.
  • a smaller quantization parameter can correspond to fine quantization (smaller quantization step size)
  • a larger quantization parameter can correspond to coarse quantization (larger quantization step size)
  • Quantization may include division by a quantization step size and corresponding quantization or inverse quantization performed by, for example, inverse quantization 210, or may include multiplication by a quantization step size.
  • Embodiments according to some standards such as HEVC may use quantization parameters to determine the quantization step size.
  • the quantization step size can be calculated based on the quantization parameter using a fixed-point approximation of an equation including division. Additional scaling factors can be introduced for quantization and inverse quantization to restore the norm of the residual block that may be modified due to the scale used in the fixed-point approximation of the equations for the quantization step size and the quantization parameter.
  • the scales of inverse transform and inverse quantization may be combined.
  • a custom quantization table can be used and signaled from the encoder to the decoder in, for example, a bitstream. Quantization is a lossy operation, where the larger the quantization step, the greater the loss.
  • the inverse quantization unit 210 is configured to apply the inverse quantization of the quantization unit 208 on the quantized coefficients to obtain the inverse quantized coefficients 211, for example, based on or use the same quantization step size as the quantization unit 208, and apply the quantization scheme applied by the quantization unit 208 The inverse quantification scheme.
  • the inversely quantized coefficient 211 may also be referred to as the inversely quantized residual coefficient 211, which corresponds to the transform coefficient 207, although the loss due to quantization is usually different from the transform coefficient.
  • the inverse transform processing unit 212 is used to apply the inverse transform of the transform applied by the transform processing unit 206, for example, an inverse discrete cosine transform (DCT) or an inverse discrete sine transform (DST), so as to be in the sample domain Obtain the inverse transform block 213.
  • the inverse transformation block 213 may also be referred to as an inverse transformation and inverse quantization block 213 or an inverse transformation residual block 213.
  • the reconstruction unit 214 (for example, the summer 214) is used to add the inverse transform block 213 (that is, the reconstructed residual block 213) to the prediction block 265 to obtain the reconstructed block 215 in the sample domain, for example, The sample value of the reconstructed residual block 213 and the sample value of the prediction block 265 are added.
  • the buffer unit 216 (or "buffer" 216 for short) of the line buffer 216 may be used to buffer or store the reconstructed block 215 and corresponding sample values, for example, for intra prediction.
  • the encoder can be used to use the unfiltered reconstructed block and/or the corresponding sample value stored in the buffer unit 216 to perform any type of estimation and/or prediction, such as intra-frame prediction.
  • the embodiment of the encoder 20 may be configured such that the buffer unit 216 is used not only for storing the reconstructed block 215 for intra prediction 254, but also for the loop filter unit 220 (not shown in FIG. 2 Out), and/or, for example, the buffer unit 216 and the decoded picture buffer unit 230 form one buffer.
  • Other embodiments may be used to use the filtered block 221 and/or blocks or samples from the decoded picture buffer 230 (neither shown in FIG. 2) as the input or basis for the intra prediction 254.
  • the loop filter unit 220 (or the loop filter 220 for short) is used to filter the reconstructed block 215 to obtain the filtered block 221, so as to smoothly perform pixel transformation or improve video quality.
  • the loop filter unit 220 is intended to represent one or more loop filters, such as deblocking filters, sample-adaptive offset (SAO) filters or other filters, such as bilateral filters, auto Adaptive loop filter (ALF), or sharpening or smoothing filter, or collaborative filter.
  • the loop filter unit 220 is shown as an in-loop filter in FIG. 2, in other configurations, the loop filter unit 220 may be implemented as a post-loop filter.
  • the filtered block 221 may also be referred to as a filtered reconstructed block 221.
  • the decoded picture buffer 230 may store the reconstructed coded block after the loop filter unit 220 performs a filtering operation on the reconstructed coded block.
  • the embodiment of the encoder 20 may be used to output loop filter parameters (e.g., sample adaptive offset information), for example, directly output or by the entropy encoding unit 270 or any other
  • the entropy coding unit outputs after entropy coding, for example, so that the decoder 30 can receive and apply the same loop filter parameters for decoding.
  • the decoded picture buffer (DPB) 230 may be a reference picture memory that stores reference picture data for the encoder 20 to encode video data.
  • DPB 230 can be formed by any of a variety of memory devices, such as dynamic random access memory (DRAM) (including synchronous DRAM (SDRAM), magnetoresistive RAM (MRAM), resistive RAM) (resistive RAM, RRAM)) or other types of memory devices.
  • DRAM dynamic random access memory
  • SDRAM synchronous DRAM
  • MRAM magnetoresistive RAM
  • RRAM resistive RAM
  • the DPB 230 and the buffer 216 may be provided by the same memory device or by separate memory devices.
  • a decoded picture buffer (DPB) 230 is used to store the filtered block 221.
  • the decoded picture buffer 230 may be further used to store other previous filtered blocks of the same current picture or different pictures such as the previously reconstructed picture, such as the previously reconstructed and filtered block 221, and may provide a complete previous Reconstruction is a decoded picture (and corresponding reference blocks and samples) and/or a partially reconstructed current picture (and corresponding reference blocks and samples), for example, for inter prediction.
  • a decoded picture buffer (DPB) 230 is used to store the reconstructed block 215.
  • the prediction processing unit 260 also called the block prediction processing unit 260, is used to receive or obtain the image block 203 (the current image block 203 of the current picture 201) and reconstructed picture data, such as the same (current) picture from the buffer 216
  • the reference samples and/or the reference picture data 231 of one or more previously decoded pictures from the decoded picture buffer 230, and used to process such data for prediction, that is, the provision can be an inter-predicted block 245 or a The prediction block 265 of the intra prediction block 255.
  • the mode selection unit 262 may be used to select a prediction mode (for example, intra or inter prediction mode) and/or the corresponding prediction block 245 or 255 used as the prediction block 265 to calculate the residual block 205 and reconstruct the reconstructed block 215.
  • a prediction mode for example, intra or inter prediction mode
  • the corresponding prediction block 245 or 255 used as the prediction block 265 to calculate the residual block 205 and reconstruct the reconstructed block 215.
  • the embodiment of the mode selection unit 262 can be used to select a prediction mode (for example, from those supported by the prediction processing unit 260) that provides the best match or minimum residual (the minimum residual means Better compression in transmission or storage), or provide minimal signaling overhead (minimum signaling overhead means better compression in transmission or storage), or consider or balance both.
  • the mode selection unit 262 may be configured to determine a prediction mode based on rate distortion optimization (RDO), that is, select a prediction mode that provides the smallest rate-distortion optimization, or select a prediction mode whose related rate-distortion at least meets the prediction mode selection criteria .
  • RDO rate distortion optimization
  • the encoder 20 is used to determine or select the best or optimal prediction mode from a set of (predetermined) prediction modes.
  • the prediction mode set may include, for example, an intra prediction mode and/or an inter prediction mode.
  • the set of intra prediction modes may include 35 different intra prediction modes, for example, non-directional modes such as DC (or mean) mode and planar mode, or directional modes as defined in H.265, or may include 67 Different intra-frame prediction modes, for example, non-directional modes such as DC (or mean) mode and planar mode, or directional modes as defined in H.266 under development.
  • the set of inter-frame prediction modes depends on the available reference pictures (ie, for example, the aforementioned at least part of the decoded pictures stored in the DBP230) and other inter-frame prediction parameters, such as whether to use the entire reference picture or only use A part of the reference picture, such as the search window area surrounding the area of the current image block, to search for the best matching reference block, and/or for example depending on whether pixel interpolation such as half-pixel and/or quarter-pixel interpolation is applied
  • the set of inter prediction modes may include, for example, an advanced motion vector prediction (AMVP) mode and a merge mode.
  • AMVP advanced motion vector prediction
  • the set of inter-frame prediction modes may include the improved AMVP mode based on control points in the embodiments of the present application, and the improved merge mode based on control points.
  • the intra prediction unit 254 may be used to perform any combination of inter prediction techniques described below.
  • the embodiments of the present application may also apply skip mode and/or direct mode.
  • the prediction processing unit 260 may be further used to divide the image block 203 into smaller block partitions or sub-blocks, for example, by iteratively using quad-tree (QT) segmentation and binary-tree (BT) segmentation. Or triple-tree (TT) segmentation, or any combination thereof, and used to perform prediction, for example, for each of the block partitions or sub-blocks, where the mode selection includes selecting the tree structure of the segmented image block 203 and selecting the application The prediction mode for each of the block partitions or sub-blocks.
  • QT quad-tree
  • BT binary-tree
  • TT triple-tree
  • the inter prediction unit 244 may include a motion estimation (ME) unit (not shown in FIG. 2) and a motion compensation (MC) unit (not shown in FIG. 2).
  • the motion estimation unit is used to receive or obtain the picture image block 203 (the current picture image block 203 of the current picture 201) and the decoded picture 231, or at least one or more previously reconstructed blocks, for example, one or more other/different
  • the reconstructed block of the previously decoded picture 231 is used for motion estimation.
  • the video sequence may include the current picture and the previously decoded picture 31, or in other words, the current picture and the previously decoded picture 31 may be part of the picture sequence forming the video sequence, or form the picture sequence.
  • the encoder 20 may be used to select a reference block from multiple reference blocks of the same or different pictures among multiple other pictures, and provide the reference picture and/or provide a reference to the motion estimation unit (not shown in FIG. 2)
  • the offset (spatial offset) between the position of the block (X, Y coordinates) and the position of the current image block is used as an inter prediction parameter.
  • This offset is also called a motion vector (MV).
  • the motion compensation unit is used to obtain inter prediction parameters, and perform inter prediction based on or using the inter prediction parameters to obtain the inter prediction block 245.
  • the motion compensation performed by the motion compensation unit may include fetching or generating a prediction block based on a motion/block vector determined by motion estimation (interpolation of sub-pixel accuracy may be performed). Interpolation filtering can generate additional pixel samples from known pixel samples, thereby potentially increasing the number of candidate prediction blocks that can be used to encode picture blocks.
  • the motion compensation unit 246 can locate the prediction block pointed to by the motion vector in a reference picture list.
  • the motion compensation unit 246 may also generate syntax elements associated with the blocks and video slices for use by the decoder 30 when decoding picture blocks of the video slices.
  • the aforementioned inter-prediction unit 244 may transmit syntax elements to the entropy encoding unit 270, and the syntax elements include inter-prediction parameters (for example, after traversing multiple inter-prediction modes, select the inter-prediction mode used for prediction of the current image block). Instructions).
  • the inter-frame prediction parameter may not be carried in the syntax element.
  • the decoder 30 can directly use the default prediction mode for decoding. It can be understood that the inter prediction unit 244 may be used to perform any combination of inter prediction techniques.
  • the intra prediction unit 254 is used to obtain, for example, receive a picture block 203 (current picture block) of the same picture and one or more previously reconstructed blocks, for example reconstructed adjacent blocks, for intra estimation.
  • the encoder 20 may be used to select an intra prediction mode from a plurality of (predetermined) intra prediction modes.
  • the embodiment of the encoder 20 may be used to select an intra prediction mode based on optimization criteria, for example, based on a minimum residual (for example, an intra prediction mode that provides a prediction block 255 most similar to the current picture block 203) or a minimum rate distortion.
  • a minimum residual for example, an intra prediction mode that provides a prediction block 255 most similar to the current picture block 203
  • a minimum rate distortion for example, an intra prediction mode that provides a prediction block 255 most similar to the current picture block 203
  • the intra prediction unit 254 is further configured to determine the intra prediction block 255 based on the intra prediction parameters of the selected intra prediction mode. In any case, after selecting the intra prediction mode for the block, the intra prediction unit 254 is also used to provide intra prediction parameters to the entropy encoding unit 270, that is, to provide an indication of the selected intra prediction mode for the block Information. In one example, the intra prediction unit 254 may be used to perform any combination of intra prediction techniques.
  • the aforementioned intra prediction unit 254 may transmit syntax elements to the entropy encoding unit 270, where the syntax elements include intra prediction parameters (for example, after traversing multiple intra prediction modes, select the intra prediction mode used for prediction of the current image block). Instructions).
  • the intra prediction parameter may not be carried in the syntax element.
  • the decoder 30 can directly use the default prediction mode for decoding.
  • the entropy coding unit 270 is used to apply entropy coding algorithms or schemes (for example, variable length coding (VLC) scheme, context adaptive VLC (context adaptive VLC, CAVLC) scheme, arithmetic coding scheme, context adaptive binary arithmetic) Coding (context adaptive binary arithmetic coding, CABAC), syntax-based context-adaptive binary arithmetic coding (SBAC), probability interval partitioning entropy (PIPE) coding or other entropy Encoding method or technique) applied to quantized residual coefficients 209, inter-frame prediction parameters, intra-frame prediction parameters and/or loop filter parameters, one or all (or not applied), to obtain the output 272
  • VLC variable length coding
  • CAVLC context adaptive VLC
  • CABAC context adaptive binary arithmetic
  • SBAC syntax-based context-adaptive binary arithmetic coding
  • PIPE probability interval partitioning entropy
  • encoded picture data 21 output in the form of encoded bitstream
  • the encoded bitstream can be transmitted to the video decoder 30, or archived for later transmission or retrieval by the video decoder 30.
  • the entropy encoding unit 270 may also be used for entropy encoding other syntax elements of the current video slice being encoded.
  • the non-transform-based encoder 20 may directly quantize the residual signal without the transform processing unit 206 for certain blocks or frames.
  • the encoder 20 may have a quantization unit 208 and an inverse quantization unit 210 combined into a single unit.
  • the encoder 20 may be used to implement the video encoding process described in the following embodiments.
  • the video encoder in this application may only include part of the modules in the video encoder 20.
  • the video encoder in this application may include an image decoding unit and a division unit.
  • the image decoding unit may be composed of one or more of an entropy decoding unit, a prediction unit, an inverse transform unit, and an inverse quantization unit.
  • the video encoder 20 may directly quantize the residual signal without being processed by the transform processing unit 206, and accordingly does not need to be processed by the inverse transform processing unit 212; or, for some For image blocks or image frames, the video encoder 20 does not generate residual data, and accordingly does not need to be processed by the transform processing unit 206, quantization unit 208, inverse quantization unit 210, and inverse transform processing unit 212; or, the video encoder 20 may The reconstructed image block is directly stored as a reference block without being processed by the filter 220; or, the quantization unit 208 and the inverse quantization unit 210 in the video encoder 20 may be combined together.
  • the loop filter 220 is optional, and for lossless compression coding, the transform processing unit 206, the quantization unit 208, the inverse quantization unit 210, and the inverse transform processing unit 212 are optional. It should be understood that, according to different application scenarios, the inter prediction unit 244 and the intra prediction unit 254 may be selectively activated.
  • FIG. 3 shows a schematic/conceptual block diagram of an example of a decoder 30 for implementing an embodiment of the present application.
  • the video decoder 30 is used to receive, for example, encoded picture data (for example, an encoded bit stream) 21 encoded by the encoder 20 to obtain a decoded picture 231.
  • video decoder 30 receives video data from video encoder 20, such as an encoded video bitstream and associated syntax elements that represent picture blocks of an encoded video slice.
  • the decoder 30 includes an entropy decoding unit 304, an inverse quantization unit 310, an inverse transform processing unit 312, a reconstruction unit 314 (such as a summer 314), a buffer 316, a loop filter 320, and The decoded picture buffer 330 and the prediction processing unit 360.
  • the prediction processing unit 360 may include an inter prediction unit 344, an intra prediction unit 354, and a mode selection unit 362.
  • video decoder 30 may perform decoding passes that are substantially reciprocal of the encoding passes described with video encoder 20 of FIG. 2.
  • the entropy decoding unit 304 is configured to perform entropy decoding on the encoded picture data 21 to obtain, for example, quantized coefficients 309 and/or decoded encoding parameters (not shown in FIG. 3), for example, inter prediction, intra prediction parameters , Loop filter parameters and/or any one or all of other syntax elements (decoded).
  • the entropy decoding unit 304 is further configured to forward the inter prediction parameters, intra prediction parameters and/or other syntax elements to the prediction processing unit 360.
  • the video decoder 30 may receive syntax elements at the video slice level and/or the video block level.
  • the inverse quantization unit 310 can be functionally the same as the inverse quantization unit 110
  • the inverse transformation processing unit 312 can be functionally the same as the inverse transformation processing unit 212
  • the reconstruction unit 314 can be functionally the same as the reconstruction unit 214
  • the buffer 316 can be functionally identical.
  • the loop filter 320 may be functionally the same as the loop filter 220
  • the decoded picture buffer 330 may be functionally the same as the decoded picture buffer 230.
  • the prediction processing unit 360 may include an inter prediction unit 344 and an intra prediction unit 354.
  • the inter prediction unit 344 may be functionally similar to the inter prediction unit 244, and the intra prediction unit 354 may be functionally similar to the intra prediction unit 254.
  • the prediction processing unit 360 is generally used to perform block prediction and/or obtain a prediction block 365 from the encoded data 21, and to receive or obtain (explicitly or implicitly) prediction-related parameters and/or information about the prediction from the entropy decoding unit 304, for example. Information about the selected prediction mode.
  • the intra-prediction unit 354 of the prediction processing unit 360 is used for the intra-prediction mode based on the signal and the previous decoded block from the current frame or picture. Data to generate a prediction block 365 for the picture block of the current video slice.
  • the inter-frame prediction unit 344 eg, motion compensation unit
  • the prediction processing unit 360 is used for the motion vector and the received from the entropy decoding unit 304
  • the other syntax elements generate a prediction block 365 for the video block of the current video slice.
  • a prediction block can be generated from a reference picture in a reference picture list.
  • the video decoder 30 may use the default construction technique to construct a list of reference frames based on the reference pictures stored in the DPB 330: list 0 and list 1.
  • the prediction processing unit 360 is used to determine prediction information for the video block of the current video slice by parsing the motion vector and other syntax elements, and use the prediction information to generate the prediction block for the current video block being decoded.
  • the prediction processing unit 360 uses some syntax elements received to determine the prediction mode (for example, intra or inter prediction) and the inter prediction slice type ( For example, B slice, P slice or GPB slice), construction information for one or more of the reference picture list for the slice, motion vector for each inter-coded video block of the slice, The inter prediction status and other information of each inter-encoded video block of the slice to decode the video block of the current video slice.
  • the syntax elements received by the video decoder 30 from the bitstream include receiving adaptive parameter set (APS), sequence parameter set (sequence parameter set, SPS), and picture parameter set (picture parameter set).
  • APS adaptive parameter set
  • SPS sequence parameter set
  • PPS picture parameter set
  • the inverse quantization unit 310 may be used to inverse quantize (ie, inverse quantize) the quantized transform coefficients provided in the bitstream and decoded by the entropy decoding unit 304.
  • the inverse quantization process may include using the quantization parameter calculated by the video encoder 20 for each video block in the video slice to determine the degree of quantization that should be applied and also determine the degree of inverse quantization that should be applied.
  • the inverse transform processing unit 312 is used to apply an inverse transform (for example, an inverse DCT, an inverse integer transform, or a conceptually similar inverse transform process) to transform coefficients so as to generate a residual block in the pixel domain.
  • an inverse transform for example, an inverse DCT, an inverse integer transform, or a conceptually similar inverse transform process
  • the reconstruction unit 314 (for example, the summer 314) is used to add the inverse transform block 313 (that is, the reconstructed residual block 313) to the prediction block 365 to obtain the reconstructed block 315 in the sample domain, for example by adding The sample value of the reconstructed residual block 313 and the sample value of the prediction block 365 are added.
  • the loop filter unit 320 (during the encoding cycle or after the encoding cycle) is used to filter the reconstructed block 315 to obtain the filtered block 321, thereby smoothly performing pixel transformation or improving video quality.
  • the loop filter unit 320 may be used to perform any combination of the filtering techniques described below.
  • the loop filter unit 320 is intended to represent one or more loop filters, such as deblocking filters, sample-adaptive offset (SAO) filters or other filters, such as bilateral filters, auto Adaptive loop filter (ALF), or sharpening or smoothing filter, or collaborative filter.
  • the loop filter unit 320 is shown as an in-loop filter in FIG. 3, in other configurations, the loop filter unit 320 may be implemented as a post-loop filter.
  • the decoded video block 321 in a given frame or picture is then stored in a decoded picture buffer 330 that stores reference pictures for subsequent motion compensation.
  • the decoder 30 is used, for example, to output the decoded picture 31 through the output 332 for presentation or viewing by the user.
  • the decoder 30 may generate an output video stream without the loop filter unit 320.
  • the non-transform-based decoder 30 may directly inversely quantize the residual signal without the inverse transform processing unit 312 for certain blocks or frames.
  • the video decoder 30 may have an inverse quantization unit 310 and an inverse transform processing unit 312 combined into a single unit.
  • the decoder 30 is used to implement the video decoding method described in the following embodiments.
  • the video encoder in this application may only include part of the modules in the video encoder 30.
  • the video encoder in this application may include a division unit and an image encoding unit.
  • the image coding unit may be composed of one or more of a prediction unit, a transformation unit, a quantization unit, and an entropy coding unit.
  • the video decoder 30 may generate an output video stream without processing by the filter 320; or, for some image blocks or image frames, the entropy decoding unit 304 of the video decoder 30 does not decode the quantized coefficients, and accordingly does not It needs to be processed by the inverse quantization unit 310 and the inverse transform processing unit 312.
  • the loop filter 320 is optional; and for lossless compression, the inverse quantization unit 310 and the inverse transform processing unit 312 are optional. It should be understood that, according to different application scenarios, the inter prediction unit and the intra prediction unit may be selectively activated.
  • the processing result for a certain link can be further processed and output to the next link, for example, in interpolation filtering, motion vector derivation or loop filtering, etc.
  • the processing result of the corresponding link is further subjected to operations such as clamping (clip) or shifting (shift).
  • the motion vector of the control point of the current image block is derived from the motion vector of the adjacent affine coding block (the coding block predicted by the affine motion model can be called the affine coding block), or the current image is derived
  • the motion vector of the sub-block of the block can be further processed, which is not limited in this application. For example, restrict the value range of the motion vector so that it is within a certain bit width. Assuming that the bit width of the allowed motion vector is bitDepth, the range of the motion vector is -2 ⁇ (bitDepth-1) ⁇ 2 ⁇ (bitDepth-1)-1, where the " ⁇ " symbol represents the power. If bitDepth is 16, the value range is -32768 ⁇ 32767. If bitDepth is 18, the value range is -131072 ⁇ 131071.
  • the value of the motion vector (for example, the motion vector MV of the four 4x4 sub-blocks in an 8x8 image block) can be restricted, so that the maximum difference between the integer parts of the four 4x4 sub-blocks MV No more than N (for example, N can take 1) pixels.
  • FIG. 4 is an explanatory diagram of an example of a video coding system 40 including the encoder 20 of FIG. 2 and/or the decoder 30 of FIG. 3 according to an exemplary embodiment.
  • the video decoding system 40 can implement a combination of various technologies in the embodiments of the present application.
  • the video coding system 40 may include an imaging device 41, an encoder 20, a decoder 30 (and/or a video encoder/decoder implemented by the logic circuit 47 of the processing unit 46), and an antenna 42 , One or more processors 43, one or more memories 44 and/or display devices 45.
  • the imaging device 41, the antenna 42, the processing unit 46, the logic circuit 47, the encoder 20, the decoder 30, the processor 43, the memory 44, and/or the display device 45 can communicate with each other.
  • the encoder 20 and the decoder 30 are used to illustrate the video coding system 40, in different examples, the video coding system 40 may include only the encoder 20 or only the decoder 30.
  • antenna 42 may be used to transmit or receive an encoded bitstream of video data.
  • the display device 45 may be used to present video data.
  • the logic circuit 47 may be implemented by the processing unit 46.
  • the processing unit 46 may include application-specific integrated circuit (ASIC) logic, a graphics processor, a general-purpose processor, and so on.
  • the video decoding system 40 may also include an optional processor 43, and the optional processor 43 may similarly include application-specific integrated circuit (ASIC) logic, a graphics processor, a general-purpose processor, and the like.
  • the logic circuit 47 may be implemented by hardware, such as dedicated hardware for video encoding, and the processor 43 may be implemented by general software, an operating system, and the like.
  • the memory 44 may be any type of memory, such as volatile memory (for example, static random access memory (SRAM), dynamic random access memory (DRAM), etc.) or non-volatile memory. Memory (for example, flash memory, etc.), etc.
  • the memory 44 may be implemented by cache memory.
  • the logic circuit 47 may access the memory 44 (e.g., to implement an image buffer).
  • the logic circuit 47 and/or the processing unit 46 may include a memory (for example, a cache, etc.) for implementing an image buffer and the like.
  • the encoder 20 implemented by logic circuits may include an image buffer (e.g., implemented by the processing unit 46 or the memory 44) and a graphics processing unit (e.g., implemented by the processing unit 46).
  • the graphics processing unit may be communicatively coupled to the image buffer.
  • the graphics processing unit may include an encoder 20 implemented by a logic circuit 47 to implement the various modules discussed with reference to Figure 2 and/or any other encoder systems or subsystems described herein.
  • Logic circuits can be used to perform the various operations discussed herein.
  • decoder 30 may be implemented by logic circuit 47 in a similar manner to implement the various modules discussed with reference to decoder 30 of FIG. 3 and/or any other decoder systems or subsystems described herein.
  • the decoder 30 implemented by logic circuits may include an image buffer (implemented by the processing unit 2820 or the memory 44) and a graphics processing unit (implemented by the processing unit 46, for example).
  • the graphics processing unit may be communicatively coupled to the image buffer.
  • the graphics processing unit may include a decoder 30 implemented by a logic circuit 47 to implement the various modules discussed with reference to FIG. 3 and/or any other decoder systems or subsystems described herein.
  • antenna 42 may be used to receive an encoded bitstream of video data.
  • the encoded bitstream may include data, indicators, index values, mode selection data, etc., related to the encoded video frame discussed herein, such as data related to coded partitions (e.g., transform coefficients or quantized transform coefficients). , (As discussed) optional indicators, and/or data defining code partitions).
  • the video coding system 40 may also include a decoder 30 coupled to the antenna 42 and used to decode the encoded bitstream.
  • the display device 45 is used to present video frames.
  • the decoder 30 may be used to perform the reverse process.
  • the decoder 30 can be used to receive and parse such syntax elements, and decode related video data accordingly.
  • the encoder 20 may entropy encode the syntax elements into an encoded video bitstream. In such instances, the decoder 30 can parse such syntax elements and decode related video data accordingly.
  • FIG. 5 is a schematic structural diagram of a video decoding device 400 (for example, a video encoding device 400 or a video decoding device 400) provided by an embodiment of the present application.
  • the video coding device 400 is suitable for implementing the embodiments described herein.
  • the video coding device 400 may be a video decoder (for example, the decoder 30 of FIG. 3) or a video encoder (for example, the encoder 20 of FIG. 2).
  • the video coding device 400 may be one or more components of the decoder 30 of FIG. 3 or the encoder 20 of FIG. 2 described above.
  • the video decoding device 400 includes: an entry port 410 for receiving data and a receiving unit (Rx) 420, a processor, logic unit or central processing unit (CPU) 430 for processing data, and a transmitter unit for transmitting data (Tx) 440 and outlet port 450, and a memory 460 for storing data.
  • the video decoding device 400 may further include a photoelectric conversion component and an electro-optical (EO) component coupled with the inlet port 410, the receiver unit 420, the transmitter unit 440, and the outlet port 450 for the outlet or inlet of optical signals or electrical signals.
  • EO electro-optical
  • the processor 430 is implemented by hardware and software.
  • the processor 430 may be implemented as one or more CPU chips, cores (for example, multi-core processors), FPGA, ASIC, and DSP.
  • the processor 430 communicates with the ingress port 410, the receiver unit 420, the transmitter unit 440, the egress port 450, and the memory 460.
  • the processor 430 includes a decoding module 470 (for example, an encoding module 470 or a decoding module 470).
  • the encoding/decoding module 470 implements the embodiments disclosed herein to implement the encoding method/decoding method of the embodiments of the present application. For example, the encoding/decoding module 470 implements, processes, or provides various encoding operations.
  • the encoding/decoding module 470 provides a substantial improvement to the function of the video decoding device 400 and affects the conversion of the video decoding device 400 to different states.
  • the encoding/decoding module 470 is implemented by instructions stored in the memory 460 and executed by the processor 430.
  • the memory 460 includes one or more magnetic disks, tape drives, and solid-state hard disks, and can be used as an overflow data storage device for storing programs when these programs are selectively executed, and storing instructions and data read during program execution.
  • the memory 460 may be volatile and/or non-volatile, and may be read-only memory (ROM), random access memory (RAM), random access memory (ternary content-addressable memory, TCAM), and/or static Random Access Memory (SRAM).
  • FIG. 6 is a simplified block diagram of an apparatus 500 that can be used as either or both of the source device 12 and the destination device 14 in FIG. 1, according to an exemplary embodiment.
  • the apparatus 500 may implement the encoding method or the decoding method in the embodiments of the present application.
  • FIG. 6 is a schematic block diagram of an implementation manner of an encoding device or a decoding device (referred to as a decoding device 500 for short) according to an embodiment of the application.
  • the decoding device 500 may include a processor 510, a memory 530, and a bus system 550.
  • the processor and the memory are connected through a bus system, the memory is used to store instructions, and the processor is used to execute instructions stored in the memory.
  • the memory of the decoding device stores program codes, and the processor can call the program codes stored in the memory to execute various video encoding or decoding methods described in this application, especially various new image block division methods. In order to avoid repetition, it will not be described in detail here.
  • the processor 510 may be a central processing unit (CPU), and the processor 510 may also be other general-purpose processors, digital signal processors (DSP), or application-specific integrated circuits (ASIC). , Ready-made programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.
  • the general-purpose processor may be a microprocessor or the processor may also be any conventional processor or the like.
  • the memory 530 may include a read only memory (ROM) device or a random access memory (RAM) device. Any other suitable type of storage device can also be used as the memory 530.
  • the memory 530 may include code and data 531 accessed by the processor 510 using the bus 550.
  • the memory 530 may further include an operating system 533 and an application program 535.
  • the application program 535 includes at least one program that allows the processor 510 to execute the video encoding or decoding method described in this application.
  • the application program 535 may include applications 1 to N, which further include a video encoding or decoding application (referred to as a video coding application) that executes the video encoding or decoding method described in this application.
  • the bus system 550 may also include a power bus, a control bus, and a status signal bus. However, for clear description, various buses are marked as the bus system 550 in the figure.
  • the decoding device 500 may further include one or more output devices, such as a display 570.
  • the display 570 may be a touch-sensitive display that merges the display with a touch-sensitive unit operable to sense touch input.
  • the display 570 may be connected to the processor 510 via the bus 550.
  • Inter prediction refers to finding a matching reference block for the current image block in the current image in the reconstructed image, and use the pixel value of the pixel in the reference block as the predicted value of the pixel value of the pixel in the current image block , (This process is called Motion estimation (ME)).
  • ME Motion estimation
  • Motion estimation is to try multiple reference blocks in the reference image for the current image block, and then use rate-distortion optimization (RDO) or other methods to finally determine one or two reference blocks from the multiple reference blocks ( Two reference blocks are required for bidirectional prediction), and the reference block is used to perform inter-frame prediction on the current image block.
  • RDO rate-distortion optimization
  • the motion information of the current image block includes the indication information of the prediction direction (usually forward prediction, backward prediction or bidirectional prediction), one or two motion vectors (motion vectors, MV) pointing to the reference block, and the reference block
  • the indication information of the image in which it is located usually recorded as a reference frame index (reference index)).
  • Forward prediction means that the current image block selects a reference image from the forward reference image set to obtain a reference block.
  • Backward prediction means that the current image block selects a reference image from the backward reference image set to obtain a reference block.
  • Bidirectional prediction refers to selecting one reference image from the forward reference image set and the backward reference image set to obtain the reference block. When the bidirectional prediction method is used, there will be two reference blocks in the current coding block, and each reference block needs a motion vector and a reference frame index to indicate, and then the pixels in the current image block are determined according to the pixel values of the pixels in the two reference blocks The predicted value of the point pixel value.
  • AMVP mode In HEVC, there are two inter prediction modes, namely AMVP mode and merge mode.
  • the AMVP mode it first traverses the current coded block's spatial or temporal adjacent coded blocks (denoted as neighboring blocks), constructs a candidate motion vector list based on the motion information of each neighboring block, and then obtains the candidate motion information from the candidate motion information through the rate distortion cost
  • the optimal motion vector is determined in the list, and the candidate motion information with the smallest rate-distortion cost is used as the motion vector predictor (MVP) of the current coding block.
  • MVP motion vector predictor
  • the rate-distortion cost can be calculated according to formula (1), where J is the rate-distortion cost, and SAD is the difference between the pixel prediction value obtained after motion estimation using the candidate motion vector prediction value and the original pixel value
  • the sum of absolute differences (SAD) R is the code rate
  • ⁇ is the Lagrangian multiplier
  • the encoder transmits the index value of the selected motion vector predictor in the candidate motion vector list and the reference frame index value To the decoding end.
  • the encoding end may perform a motion search in the neighborhood centered on the MVP to obtain the actual motion vector of the current encoding block, and then transmit the difference between the MVP and the actual motion vector (motion vector difference) to the decoding end.
  • AMVP modes can be divided into AMVP modes based on translational models and AMVP modes based on non-translational models.
  • the candidate motion information list is constructed by using the motion information of the current coding unit adjacent to the coding unit in the spatial or temporal domain, and then the optimal motion information is determined from the candidate motion information list by the rate distortion cost as the current The motion information of the coding unit, and finally the index value (denoted as merge index, the same below) of the position of the optimal motion information in the candidate motion information list is passed to the decoding end.
  • the spatial and temporal candidate motion information of the current coding unit can be as shown in Figure 7, where the spatial candidate motion information comes from 5 adjacent blocks (A0, A1, B0, B1 and B2) in space. If the neighboring block is not available or the prediction mode is intra prediction, the neighboring block is not added to the candidate motion information list.
  • the temporal candidate motion information of the current coding unit can be obtained after scaling the MV of the corresponding block in the reference frame according to the picture order count (POC) of the reference frame and the current frame.
  • POC picture order count
  • Non-translational motion model prediction refers to the use of the same motion model on the codec side to derive the motion information of each sub-motion compensation unit in the current coding block, and then perform motion compensation according to the motion information of the sub-motion compensation unit to obtain each sub-block The prediction sub-block, thereby improving the prediction efficiency.
  • Commonly used non-translational motion models include 4-parameter affine motion model or 6-parameter affine motion model.
  • the Doford grid pictures near the same geographic location in the positioning layer are combined into an image sequence, and then inter-frame prediction coding is performed on the image sequence, which can be obtained according to the inter-frame prediction process.
  • the data amount of the residual picture of the grid picture is small, so that the data amount of the code stream generated by the final encoding is also relatively small, thereby reducing the storage overhead occupied by the code stream generated by the encoding.
  • Fig. 8 is a schematic diagram of a process of an image coding method according to an embodiment of the present application.
  • the method shown in FIG. 8 may be executed by an encoding device or an encoder.
  • Fig. 8 shows the main process of the image coding method according to the embodiment of the present application.
  • images with similar geographical locations can be combined into an image sequence (images with similar image content can also be combined into an image sequence).
  • the coding method based on inter-frame prediction is used for coding to obtain the code stream.
  • the encoding based on inter-frame prediction here refers to an encoding method that uses inter-frame prediction when predicting an image.
  • the predicted image is obtained by performing inter-frame prediction on the images in the image sequence, and the residual image of the image is obtained according to the obtained predicted image.
  • the data amount of the residual image finally obtained is small, and the data amount of the code stream generated by the final encoding is also small, so that the storage space occupied by the code stream can be reduced.
  • the pixel values of the image can be XORed or inverted after the image is obtained, or the geographically adjacent images can be formed into an image sequence after the image is obtained, and then the pictures in the image sequence can be processed XOR processing or negation processing.
  • the image is first XORed or inverted.
  • the images with similar geographic locations are selected from the processed images to form an image sequence, and then based on inter-frame prediction Encoding encodes the image sequence to obtain a bitstream.
  • the images with similar geographic locations are first formed into an image sequence, and then the images in the image sequence are XORed or inverted, and then based on the inter-frame prediction encoding method.
  • the processed image sequence is coded to obtain a code stream.
  • FIG. 11 is a schematic flowchart of an image decoding method according to an embodiment of the present application.
  • the method shown in FIG. 11 may be executed by a decoding device or a decoder.
  • the method shown in FIG. 11 includes steps 1001 to 1004, and steps 1001 to 1004 are described in detail below.
  • the code stream obtained in step 1001 may be a code stream obtained by encoding in the encoding method shown in FIG. 14 below.
  • step 1002 the residual block of the current image block can be obtained by parsing the code stream.
  • parsing process refer to the relevant decoding process shown in FIG. 3.
  • the aforementioned image sequence includes a plurality of grid images, and the geographical locations corresponding to the multiple grid images are similar or the image content of the multiple grid images is similar. Specifically, that the geographic locations corresponding to the multiple grid images are similar or the image content of the multiple grid images is similar may mean that the multiple grid images satisfy the first condition.
  • the above-mentioned first condition has many different specific manifestations.
  • the foregoing first condition may be that the distance between geographic locations corresponding to at least two of the multiple grid images in the foregoing image sequence is less than a preset distance.
  • the aforementioned preset distance may also become a distance threshold, and the size of the preset distance can be flexibly set according to actual needs.
  • the aforementioned preset distance may be set to 3m (3m).
  • the preset distance can also be set to 5m, 6m, etc. In short, any suitable size preset distance can be set as needed.
  • the foregoing first condition may also be that the distance between the geographic locations corresponding to at least two of the plurality of grid images is less than or equal to a preset distance.
  • the foregoing first condition may be that the similarity of the image content of the at least two grid images in the image sequence is greater than or equal to a preset similarity.
  • the aforementioned preset similarity may also be referred to as a similarity threshold, and the size of the preset similarity can be flexibly set according to actual needs.
  • the aforementioned preset similarity may be set to 50%.
  • the preset similarity can also be set to 55%, 60%, 65%, etc. In short, any suitable size of the preset similarity can be set as needed.
  • the above-mentioned first condition may also be that the similarity of the image content of at least two of the plurality of grid images is greater than the preset similarity.
  • the image sequence contains at least two grid images with similar image content
  • the data amount of the residual image obtained subsequently can be made smaller.
  • the foregoing first condition may be that the image content of at least two grid images in the plurality of grid images corresponds to the same geographic area.
  • the inter-frame prediction of the image sequence can make the residual image The data amount of the difference image is small.
  • the size of the aforementioned geographic area may be a preset size, and the size of the geographic area may be set according to actual needs.
  • the size of the aforementioned geographic area may be an area of 2m ⁇ 2m. It should be understood that the size of the geographic area of the 2m ⁇ 2m area here is only an example.
  • the size of the geographic area may also be set to an area of 1m ⁇ 1m, an area of 3m ⁇ 32m, etc., in short, any suitable size of geographic area can be set as needed. area.
  • the size of the aforementioned geographic area is an area of 2m ⁇ 2m.
  • the two grid images satisfy the first condition.
  • At least two grid images in the plurality of grid images may be grid images with adjacent frames between each other.
  • At least two grid images satisfying the first condition are adjacent frames between each other.
  • the grid image 1, the grid image 2, and the grid image 3 in the aforementioned image sequence satisfy the aforementioned first condition.
  • the grid image 1, the grid image 2 and the grid image 3 may be the i-th frame, the i+1-th frame and the i+2-th frame in the image sequence, respectively.
  • i is a positive integer.
  • step 1003 For the process of obtaining the predicted image of the grid image in the image sequence through inter-frame prediction in step 1003, refer to the relevant decoding process shown in FIG. 3.
  • the grid image in the image sequence can be obtained by superimposing the residual image of the grid image in the image sequence and the predicted image of the grid image in the image sequence.
  • the predicted image of the grid image may be composed of prediction blocks of each image block in the grid image
  • the residual image of the grid image may be composed of each image in the grid image.
  • the residual block composition of the block Therefore, in the method of FIG. 11, in the process of parsing the code stream to finally obtain the grid image in the image sequence, the decoding operation may be performed with the image block as the basic unit.
  • the decoding operation may be performed according to the code Obtain the residual block of the image block of the grid image in the image sequence, and then perform inter-frame prediction on the image block in step 1003 to obtain the prediction block of the image block.
  • step 1004 according to the residual Block and prediction block, and finally get the corresponding image block.
  • the image blocks can be spliced into a grid image. In this way, at the decoding end, it is equivalent to obtaining the grid image based on the residual image of the grid image and the predicted image of the grid image.
  • step 1004 For the specific implementation of the foregoing step 1004, reference may be made to the relevant decoding process shown in FIG. 3.
  • the image sequence contains grid images with similar geographic locations or similar image content
  • the amount of residual image data obtained can be made smaller, so that the final The code stream corresponding to the image sequence occupies a small storage space, which is convenient for storage or transmission.
  • the encoding end may also perform inversion processing or XOR processing on the pixel values of the grid image in the image sequence to To further reduce the storage space occupied by the code stream generated by encoding, correspondingly, the decoding end can also perform inversion processing or exclusive OR processing on the corresponding image during or after decoding, so as to obtain the final image.
  • This processing method is described in detail below.
  • the grid image in the image sequence can be processed to obtain the final grid image.
  • the method shown in FIG. 11 further includes:
  • the pixel value of the grid image in the above image sequence is represented by M bits, and the value of each bit is 0 or 1, and M is an integer greater than 1.
  • the processed grid image and grid image obtained in step 1005 above may satisfy the first relationship.
  • the first relationship the pixel value of the processed grid image is opposite to the pixel value of the grid image.
  • the value of the i-th bit among the N bits of the pixel value of the grid image in the image sequence is the same as the N bits of the pixel value of the grid image in the processed image sequence
  • the value of the i-th bit in is the opposite, and the N bits of the pixel value of the grid image in the image sequence are at the same position as the N bits of the pixel value of the grid image in the processed image sequence;
  • the N bits of the pixel value of the grid image in the sequence are located after and adjacent to the first bit of the pixel value of the grid image in the image sequence.
  • the first bit is the pixel of the grid image in the image sequence.
  • i and N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoder end by inverting the pixel value of the grid image can reduce the data volume of the grid image when the pixel value of the grid image contains continuous placeholders, thereby making the encoding generation
  • the code stream occupies less storage space, and the decoding end performs (inversion) processing on the decoded grid image, so as to restore the grid image processed (inversion processing) on the encoding end to obtain the final Grid image.
  • the pixel value of the grid image of the image sequence can also be XORed.
  • the processed grid image and grid image obtained in step 1005 can also satisfy the second relationship.
  • the second relationship the pixel value of the processed grid image is the XOR result of the pixel value.
  • the value of the first bit among the N bits of the grid image in the processed image sequence is the same as the value of the first bit among the N bits of the grid image in the image sequence
  • the value of the i+1th bit among the N bits of the grid image in the processed image sequence is the i+1th bit among the N bits of the grid image in the image sequence
  • the value of is the result of XOR processing the i-th bit of the N bits of the grid image in the processed image sequence
  • the N bits of the pixel value of the grid image in the image sequence are located in the image sequence
  • the first bit is the bit with the highest value of 1 in the pixel value of the grid image in the image sequence, or the image sequence
  • the N bits of the pixel value of the grid image in the image sequence are located after the highest bit of the pixel value of the grid image in the image sequence and adjacent to the highest bit of the pixel value of the grid image in the image sequence.
  • the N bits of the pixel value of the grid image in the image sequence are at the same position as the N bits of the pixel value of the grid image in the processed image sequence, and the i-th bit The number of bits of is higher than the number of bits of the i+1th bit, i and N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoding end performs exclusive OR processing on the pixel values of the grid image, so that when the pixel values of the grid image contain continuous placeholders, the data volume of the grid image can be reduced, thereby making the code generated
  • the code stream occupies less storage space
  • the decoder performs (exclusive OR) processing on the decoded grid image, so as to restore the grid image processed (exclusive or processed) on the encoder side to obtain the final Grid image.
  • step 1003a may be performed.
  • step 1004 is to obtain the grid image in the image sequence according to the processed residual image and the predicted image of the grid image in the image sequence.
  • the pixel value of the above residual image is represented by M bits, and the value of each bit is 0 or 1, and M is an integer greater than 1.
  • the processed residual image and residual image obtained in the above step 1003a may satisfy the third relationship.
  • the third relationship the value of the pixel value of the processed residual image is opposite to the value of the pixel value of the residual image.
  • the value of the i-th bit among the N bits of the pixel value of the residual image is equal to the value of the i-th bit among the N bits of the pixel value of the processed residual image
  • the values of the bits are opposite, and the positions of the N bits of the pixel value of the residual image are the same as the positions of the N bits of the pixel value of the processed residual image.
  • the N bits of the pixel value of the residual image are located after and adjacent to the first bit of the pixel value of the residual image.
  • the first bit is the pixel value of the residual image with the value 1 and the highest number of bits.
  • Bit position, i and N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoding end by inverting the pixel value of the residual image can reduce the amount of data of the residual image when the pixel value of the residual image contains continuous placeholders, thereby making the code generated
  • the code stream occupies less storage space, and the decoder can restore the residual image processed (inverted) by the encoding end by (inverting) the decoded residual image, and then according to the processing After the residual image gets the final image block.
  • the pixel value of the residual image may also be XORed.
  • the processed residual image and residual image obtained in step 1003a may also satisfy the fourth relationship.
  • the fourth relationship the pixel value of the processed residual image is the result of the exclusive OR of the pixel value.
  • the value of the first bit of the N bits of the processed residual image is opposite to the value of the first bit of the N bits of the residual image, and the processed The value of the i+1th bit among the N bits of the residual image is the value of the i+1th bit among the N bits of the residual image and the value of the N bits of the processed residual image The result of XORing the i-th bit.
  • the N bits of the pixel value of the residual image are located after and adjacent to the first bit of the pixel value of the residual image.
  • the first bit is the pixel value of the residual image with the value 1 and the highest number of bits.
  • the bit position, or, the N bits of the pixel value of the residual image are located after the highest bit of the pixel value of the residual image and adjacent to the highest bit of the pixel value of the residual image.
  • the N bits of the pixel value of the residual image are at the same position as the N bits of the pixel value of the processed residual image, and the number of bits of the i-th bit is higher than that of the i+th bit.
  • the number of bits in 1 bit, i and N are both positive integers, i ⁇ N, N ⁇ M;
  • the encoding end performs XOR processing on the pixel values of the residual image, so that when the pixel values of the residual image contain continuous placeholders, the data volume of the residual image can be reduced, so that the encoded
  • the code stream occupies less storage space
  • the decoding end performs (exclusive OR) processing on the decoded residual image, so as to restore the residual image processed (exclusive or processed) by the encoding end, and then according to the processing After the residual image gets the final image block.
  • the encoding end may use lossless encoding or lossy encoding when encoding the grid images in the image sequence. Accordingly, the decoding end shall use a matching method with the encoding end for decoding.
  • obtaining the residual image of the grid image in the image sequence includes: performing inverse transformation, inverse quantization and entropy decoding processing on the code stream to obtain the residual image .
  • the above-mentioned decoding processing corresponds to the lossy encoding of the image, which can make the code stream obtained by encoding occupy as little storage space as possible.
  • obtaining the residual image of the grid image in the image sequence according to the code stream in step 1002 includes: performing entropy decoding processing on the code stream to obtain the residual image.
  • the foregoing decoding method that only performs entropy decoding processing corresponds to lossless encoding.
  • This encoding method can avoid image distortion as much as possible and ensure the final display effect of the image.
  • the above code stream is obtained by encoding the positioning layer.
  • the pixel values of the above positioning layer include rasterized elevation data.
  • the pixel value of the above positioning layer contains M bits, and each bit represents the occupied position of each grid. Since the pixel value of the positioning layer contains the rasterized elevation data, and the character "11" in the high position of the elevation data has a higher probability, the pixel value of the positioning layer containing the elevation data can be processed. Reduce the data volume of the pixel value of the positioning layer, thereby reducing the storage space occupied by the finally obtained code stream.
  • the value of M may be any one of 8, 10, and 12.
  • FIG. 14 is a schematic flowchart of an image coding method according to an embodiment of the present application.
  • the method shown in FIG. 14 may be executed by an encoding device or an encoder.
  • the method shown in FIG. 14 includes steps 2001 to 2003, and steps 2001 to 2003 will be described in detail below.
  • performing inter-frame prediction on the grid images in the image sequence to obtain the residual image includes: performing inter-frame prediction on the grid images in the image sequence to obtain a predicted image; and according to the grid images in the image sequence Image and predicted image, get the residual image of the grid image.
  • the grid image and the residual image of the grid image may be subtracted to obtain the residual image of the grid image.
  • the aforementioned image sequence includes a plurality of grid images, and the geographical locations corresponding to the multiple grid images are similar or the image contents of the multiple grid images are similar.
  • that the geographic locations corresponding to the multiple grid images are similar or the image content of the multiple grid images is similar may mean that the multiple grid images satisfy the first condition.
  • the above-mentioned first condition has many different specific manifestations.
  • the foregoing first condition may be that the distance between geographic locations corresponding to at least two of the multiple grid images in the foregoing image sequence is less than a preset distance.
  • the aforementioned preset distance may also become a distance threshold, and the size of the preset distance can be flexibly set according to actual needs.
  • the aforementioned preset distance may be set to 3m.
  • the preset distance can also be set to 5m, 6m, etc. In short, any suitable size preset distance can be set as needed.
  • the foregoing first condition may also be that the distance between the geographic locations corresponding to at least two of the plurality of grid images is less than or equal to a preset distance.
  • the foregoing first condition may be that the similarity of the image content of the at least two grid images in the image sequence is greater than or equal to a preset similarity.
  • the aforementioned preset similarity may also be referred to as a similarity threshold, and the size of the preset similarity can be flexibly set according to actual needs.
  • the aforementioned preset similarity may be set to 50%.
  • the preset similarity can also be set to 55%, 60%, 65%, etc. In short, any suitable size of the preset similarity can be set as needed.
  • the above-mentioned first condition may also be that the similarity of the image content of at least two of the plurality of grid images is greater than the preset similarity.
  • the image sequence contains at least two grid images with similar image content
  • the data amount of the residual image obtained subsequently can be made smaller.
  • the foregoing first condition may be that the image content of at least two grid images in the plurality of grid images corresponds to the same geographic area.
  • the inter-frame prediction of the image sequence can make the residual image The data amount of the difference image is small.
  • the size of the aforementioned geographic area may be a preset size, and the size of the geographic area may be set according to actual needs.
  • the size of the aforementioned geographic area may be an area of 2m ⁇ 2m. It should be understood that the size of the geographic area of the 2m ⁇ 2m area here is only an example.
  • the size of the geographic area may also be set to an area of 1m ⁇ 1m, an area of 3m ⁇ 32m, etc., in short, any suitable size of geographic area can be set as needed. area.
  • the size of the aforementioned geographic area is an area of 2m ⁇ 2m.
  • the two grid images satisfy the first condition.
  • the aforementioned at least two grid images may be grid images with adjacent frames between each other.
  • At least two grid images satisfying the first condition are adjacent frames between each other.
  • grid image 1, grid image 2, and grid image 3 in the aforementioned image sequence satisfy the aforementioned first condition.
  • the grid image 1, the grid image 2 and the grid image 3 may be the i-th frame, the i+1-th frame and the i+2-th frame in the image sequence, respectively.
  • i is a positive integer.
  • the image sequence contains grid images with similar geographic locations or similar image content
  • the amount of residual image data obtained can be made smaller, so that the final The code stream obtained by encoding the image sequence occupies a small storage space, which is convenient for storage or transmission.
  • the predicted image of the grid image can be composed of the predicted blocks of each image block in the grid image
  • the residual image of the grid image can be composed of the prediction blocks of each image block in the grid image. Residual block composition.
  • the residual image can be divided into image blocks, and then the prediction block of each image block is obtained, and the residual block of each image block is obtained according to each image block and the residual block of each image block. Difference block, and then obtain the residual image of the grid image.
  • the encoding end may also perform inversion processing or XOR processing on the pixel values of the grid image in the image sequence to Further reduce the storage space occupied by the code stream generated by the encoding.
  • the grid image in the image sequence may be processed first, and then the processed grid image may be encoded. .
  • step 2002a is performed first.
  • step 2002 is to perform inter-frame prediction based on the processed grid image to obtain a residual image.
  • the pixel value of the grid image in the above image sequence is represented by M bits, and the value of each bit is 0 or 1, and M is an integer greater than 1.
  • the processed grid image and grid image obtained in the foregoing step 2002a may satisfy the fifth relationship.
  • the fifth relationship the pixel value of the processed grid image is opposite to the pixel value of the grid image.
  • the value of the i-th bit among the N bits of the pixel value of the grid image in the image sequence is equal to the N bits of the pixel value of the grid image in the processed image sequence
  • the value of the i-th bit in is the opposite, and the N bits of the pixel value of the grid image in the image sequence are at the same position as the N bits of the pixel value of the grid image in the processed image sequence.
  • the N bits of the pixel value of the grid image in the image sequence are located after and adjacent to the first bit of the pixel value of the grid image in the image sequence.
  • the first bit is The pixel value of the grid image in the image sequence is 1 and the bit with the highest number of bits, i and N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoding end uses the inverse processing of the pixel values of the grid image to reduce the data volume of the grid image when the pixel value of the grid image contains continuous placeholders, thereby making the code generated
  • the code stream takes up less storage space.
  • N the corresponding coding performance is different.
  • N takes a certain value
  • the corresponding coding performance is the best, and the number of bits reduced is the most.
  • the pixel values of the grid images in the image sequence can also be XORed.
  • the processed grid image and grid image obtained in the above step 2002a can also satisfy the sixth relationship.
  • the sixth relationship the pixel value of the processed grid image is the XOR result of the pixel value.
  • the value of the first bit among the N bits of the grid image in the processed image sequence is the same as the value of the first bit among the N bits of the grid image in the image sequence
  • the value of the i+1th bit among the N bits of the grid image in the processed image sequence is the i+1th bit among the N bits of the grid image in the image sequence
  • the value of is the result of XORing the i-th bit among the N bits of the grid image in the processed image sequence.
  • the N bits of the pixel value of the grid image in the image sequence are located after and adjacent to the first bit of the pixel value of the grid image in the image sequence.
  • the first bit is The pixel value of the grid image in the image sequence is 1 and the bit with the highest digit, or the N bits of the pixel value of the grid image in the image sequence are located in the pixel value of the grid image in the image sequence After the highest bit of and adjacent to the highest bit of the pixel value of the grid image in the image sequence.
  • the N bits of the pixel value of the grid image in the image sequence are at the same position as the N bits of the pixel value of the grid image in the processed image sequence, and the number of bits of the i-th bit is higher than that of the i+th bit
  • the number of bits in 1 bit, i and N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoding end performs exclusive OR processing on the pixel values of the grid image, so that when the pixel values of the grid image contain continuous placeholders, the data volume of the grid image can be reduced, thereby making the code generated
  • the code stream takes up less storage space.
  • the corresponding coding performance is different.
  • the corresponding coding performance is better and the number of bits reduced is also greater.
  • the value of N can be set according to the test results or experience. For example, when the pixel value of the grid image corresponds to a total of 8 bits, you can set a larger value for N, for example, set N Set to 5 or 6, which can achieve better coding performance and reduce the amount of grid image data as much as possible.
  • the grid images of the image sequence can also be obtained. After the residual image of the grid image, the residual image is inverted or XOR processed. The details are described below.
  • step 2003 may specifically include step 2003a and step 2003b.
  • the pixel value of the above residual image is represented by M bits, and the value of each bit is 0 or 1, and M is an integer greater than 1.
  • the processed residual image and residual image obtained in step 1003a above may satisfy the seventh relationship.
  • the seventh relationship the value of the pixel value of the processed residual image is opposite to the value of the pixel value of the residual image.
  • the value of the i-th bit among the N bits of the pixel value of the residual image is equal to the value of the i-th bit among the N bits of the pixel value of the residual image after processing.
  • the values are opposite, and the N bits of the pixel value of the residual image are at the same position as the N bits of the pixel value of the processed residual image.
  • the N bits of the pixel value of the residual image are located after and adjacent to the first bit of the pixel value of the residual image.
  • the first bit is the pixel value of the residual image with the value 1 and the highest number of bits.
  • Bit position, i and N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoding end performs XOR processing on the pixel values of the residual image, so that when the pixel values of the residual image contain continuous placeholders, the data amount of the residual image can be reduced, thereby enabling the encoding
  • the generated code stream takes up less storage space.
  • the pixel value of the residual image in addition to inverting the pixel value of the residual image, the pixel value of the residual image can also be XORed.
  • the processed residual image and residual image obtained in step 2003a may also satisfy the eighth relationship.
  • the eighth relationship the pixel value of the processed residual image is the result of the exclusive OR of the pixel value.
  • the value of the i-th bit among the N bits of the pixel value of the residual image is equal to the value of the i-th bit among the N bits of the pixel value of the residual image after processing.
  • the value is opposite, the value of the i+1th bit among the N bits of the processed residual image is the value of the i+1th bit among the N bits of the residual image and the processed residual image.
  • the N bits of the pixel value of the residual image are located after and adjacent to the first bit of the pixel value of the residual image, and the first bit is the pixel value of the residual image.
  • the bit with a value of 1 and the highest number of bits, or the N bits of the pixel value of the residual image are located after the highest bit of the pixel value of the residual image and adjacent to the highest bit of the pixel value of the residual image.
  • the N bits of the pixel value of the residual image are at the same position as the N bits of the pixel value of the processed residual image.
  • the number of bits of the i-th bit is higher than that of the i+1th bit, i And N are both positive integers, i ⁇ N, N ⁇ M.
  • the encoding end performs XOR processing on the pixel values of the residual image, so that when the pixel values of the residual image contain continuous placeholders, the data amount of the residual image can be reduced, thereby enabling the encoding
  • the generated code stream takes up less storage space.
  • lossless coding or lossy coding may be used.
  • encoding the residual image in step 2003 to obtain an encoded bitstream includes: performing transformation, quantization, and entropy encoding processing on the residual image to obtain an encoded bitstream.
  • the encoded code stream can occupy as little storage space as possible.
  • encoding the residual image in step 2003 to obtain an encoded bitstream includes: performing entropy encoding processing on the residual image to obtain an encoded bitstream.
  • the grid pictures in the aforementioned image sequence come from a positioning layer.
  • the pixel values of the above positioning layer include rasterized elevation data.
  • the pixel value of the above positioning layer contains M bits, and each bit represents the occupied position of each grid. Since the pixel value of the positioning layer contains the rasterized elevation data, and the character "11" in the high position of the elevation data has a higher probability, the pixel value of the positioning layer containing the elevation data can be processed. Reduce the data volume of the pixel value of the positioning layer, thereby reducing the storage space occupied by the finally obtained code stream.
  • the value of M can be any one of 8, 10, and 12.
  • the grid images in the image sequence may include I frame images and P frame images. As shown in FIG. 19, the image sequence contains 1 I frame and 3 P frames. For the P frames, the inter-frame prediction method can be used for prediction. It should be understood that the image sequence shown in FIG. 19 is only for illustration, and the number of grid images included in the image sequence is not limited in the embodiment of the present application.
  • image sequence in the embodiment of the present application may also include B frames.
  • the grid image in the image sequence may come from a positioning layer, and the positioning layer may be 2D plane data obtained by mapping 3D point cloud data.
  • the 3D point cloud data contains data such as three-dimensional coordinates (x, y, z) and reflectance (r).
  • the (x, y) of the 3D point cloud data can be directly As the (x, y) coordinates of the 2D plane data (x and y are equivalent to the position of the pixel in the picture), the height z in the 3D point cloud data is mapped to the R channel of the 2D plane data, and the reflectivity r is mapped to On the G channel, the conversion of 3D point cloud data to 2D plane data is thus realized.
  • Sequence 1 and Sequence 2 are two image sequences respectively. Both image sequences contain pictures in portable network graphics (PNG) format. Sequence 1 contains 4 grids. Pictures (1a.png, 1b.png, 1c.png, 1d.png), sequence 2 also includes 4 grid pictures (2a.png, 2b.png, 2c.png, 2d.png).
  • HEVC-SCC high efficiency video coding-screen content coding
  • HEVC-SCC combined compression (Equivalent to the coding method in the embodiment of the present application) when the image sequence is coded, the data volume of the obtained code stream is smaller.
  • the data volume after HEVC-SCC combined compression is reduced by 9.9% relative to the data volume of the original image sequence, and the data volume after HEVC-SCC alone compression is reduced by 9.5 relative to the data volume of the original image sequence. %.
  • the code stream obtained by using the HEVC-SCC combined compression + data preprocessing method is compared with that of using HEVC-SCC alone. Compared with the SCC combined compression method, the data volume of the obtained code stream is smaller.
  • the data volume of the code stream obtained by using the HEVC-SCC combined compression method alone is reduced by 9.9% relative to the data volume of the original image sequence, while the HEVC-SCC combined compression + data preprocessing method is used
  • the data volume of the obtained code stream is reduced by 10.3% relative to the data volume of the original image sequence.
  • FIGS. 21 to 24 The image decoding method and encoding method of the embodiments of the present application are described in detail above with reference to the drawings, and the image decoding apparatus and image encoding apparatus of the embodiments of the present application will be introduced below with reference to FIGS. 21 to 24. It should be understood that the image decoding device in FIG. 21 to FIG. 24 can execute the image decoding method in the embodiment of the present application, and the image encoding device in FIG. 21 to FIG. 24 can execute the image encoding method in the embodiment of the present application. In order to avoid unnecessary repetition, repetitive descriptions are appropriately omitted when introducing the image decoding device and the image encoding device of the embodiments of the present application.
  • FIG. 21 is a schematic block diagram of an image decoding device according to an embodiment of the present application.
  • the image decoding device 10000 shown in FIG. 21 includes an acquisition unit 10001 and a processing unit 10002.
  • the image decoding device 10000 may execute the image decoding method according to the embodiment of the present application. Specifically, the image decoding device 10000 may execute the image decoding method shown in FIG. 11 to FIG. 13.
  • Fig. 22 is a schematic block diagram of an image encoding device according to an embodiment of the present application.
  • the image encoding device 11000 shown in FIG. 22 includes an acquisition unit 11001 and a processing unit 11002.
  • the image encoding device 11000 can execute the image encoding method of the embodiment of the present application. Specifically, the image encoding device 11000 can execute the image encoding methods shown in FIG. 14, FIG. 15, and FIG. 18.
  • FIG. 23 is a schematic diagram of the hardware structure of an image decoding device provided by an embodiment of the present application.
  • the image decoding apparatus 12000 shown in FIG. 23 (the image decoding apparatus 12000 may specifically be a computer device) includes a memory 1201, a memory 1202, a communication interface 12003, and a bus 12004. Among them, the memory 1201, the memory 1202, and the communication interface 12003 realize the communication connection between each other through the bus 12004.
  • the memory 1201 may be a read only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM).
  • the memory 12001 may store a program. When the program stored in the memory 12001 is executed by the memory 1202, the memory 1202 is used to execute each step of the image decoding method in the embodiment of the present application.
  • the memory 1202 may adopt a general central processing unit (CPU), a microprocessor, an application specific integrated circuit (ASIC), a graphics processing unit (GPU), or one or more integrated circuits.
  • the circuit is used to execute related programs to implement the image decoding method in the method embodiment of the present application.
  • the memory 12002 may also be an integrated circuit chip with signal processing capability.
  • each step of the image decoding method of the present application can be completed by an integrated logic circuit of hardware in the memory 1202 or instructions in the form of software.
  • the above-mentioned memory 1202 may also be a general-purpose processor, a digital signal processing (digital signal processing, DSP), an application specific integrated circuit (ASIC), a ready-made programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices , Discrete hardware components.
  • DSP digital signal processing
  • ASIC application specific integrated circuit
  • FPGA ready-made programmable gate array
  • the methods, steps, and logical block diagrams disclosed in the embodiments of the present application can be implemented or executed.
  • the general-purpose processor may be a microprocessor or the processor may also be any conventional processor or the like.
  • the steps of the method disclosed in the embodiments of the present application may be directly embodied as being executed and completed by a hardware decoding processor, or executed and completed by a combination of hardware and software modules in the decoding processor.
  • the software module can be located in a mature storage medium in the field such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers.
  • the storage medium is located in the memory 12001, and the processor 12002 reads the information in the memory 12001, and combines its hardware to complete the functions required by the units included in the image decoding device, or execute the image decoding method in the method embodiment of the present application.
  • the communication interface 12003 uses a transceiving device such as but not limited to a transceiver to implement communication between the image decoding device 12000 and other devices or communication networks. For example, the information of the neural network to be constructed and the training data needed in the process of constructing the neural network can be obtained through the communication interface 12003.
  • a transceiving device such as but not limited to a transceiver to implement communication between the image decoding device 12000 and other devices or communication networks. For example, the information of the neural network to be constructed and the training data needed in the process of constructing the neural network can be obtained through the communication interface 12003.
  • the bus 12004 may include a path for transferring information between various components of the image decoding device 12000 (for example, the memory 1201, the memory 1202, and the communication interface 12003).
  • the acquisition unit 10001 and the processing unit 10002 in the image decoding device 10000 described above are equivalent to the processor 12002 in the image decoding device 12000.
  • FIG. 24 is a schematic diagram of the hardware structure of an image encoding device provided by an embodiment of the present application.
  • the image encoding apparatus 13000 shown in FIG. 24 (the image decoding apparatus 13000 may specifically be a computer device) includes a memory 13001, a processor 13002, a communication interface 13003, and a bus 13004. Among them, the memory 13001, the processor 13302, and the communication interface 13003 implement communication connections between each other through the bus 13004.
  • each module in the image decoding device 12000 is also applicable to the image encoding device 13000, and will not be described in detail here.
  • the above-mentioned memory 13001 may be used to store a program.
  • the processor 13002 is used to execute the program stored in the memory 13001.
  • the processor 13002 is used to execute each step of the image encoding method in the embodiment of the present application.
  • the image encoding device 13000 when it encodes an image, it can acquire the image through a communication interface, and then encode the acquired image to obtain encoded data.
  • the encoded data can be transmitted to the video decoding device through the communication interface 13003 .
  • the image encoding device 13000 When the image encoding device 13000 decodes an image, it can obtain a video image through a communication interface, and then decode the obtained image to obtain an image to be displayed.
  • the acquisition unit 11001 and the processing unit 11002 in the image encoding device 11000 described above are equivalent to the processor 13002 in the image encoding device 13000.
  • the disclosed system, device, and method may be implemented in other ways.
  • the device embodiments described above are only illustrative.
  • the division of the units is only a logical function division, and there may be other divisions in actual implementation, for example, multiple units or components can be combined or It can be integrated into another system, or some features can be ignored or not implemented.
  • the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, and may be in electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solutions of the embodiments.
  • each unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit.
  • the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium.
  • the technical solution of this application essentially or the part that contributes to the existing technology or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in each embodiment of the present application.
  • the aforementioned storage media include: U disk, mobile hard disk, read-only memory (read-only memory, ROM), random access memory (random access memory, RAM), magnetic disk or optical disk and other media that can store program code .

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Abstract

本申请提供了图像编码方法、解码方法、装置和存储介质。该图像解码方法包括获取码流，并根据码流获取图像序列中的网格图像的残差图像，其中，该图像序列包括多个网格图像，该多个网格图像对应的地理位置相近或者该多个网格图像的图像内容相近。对图像序列中的网格图像进行帧间预测，得到图像序列中的网格图像的预测图像；根据图像序列中的网格图像的残差图像和图像序列中的网格图像的预测图像，得到图像序列中的网格图像。本申请实施例能够减小码流的存储开销。

Description

图像编码方法、解码方法、装置和存储介质
本申请要求于2019年7月15日提交中国专利局、申请号为201910636152.3、申请名称为“图像编码方法、解码方法、装置和存储介质”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及图像编解码技术领域，并且更具体地，涉及一种图像编码方法、解码方法、装置和存储介质。
背景技术
激光探测及测距***(light laser detection and ranging，LiDAR)是采用激光器作为辐射源的雷达***，可以简称为激光雷达。激光雷达是激光技术与雷达技术相结合的产物，激光雷达具有检测精度高、测量范围大，非接触，3D和360度测量等特点。激光雷达常用于高精地图构建，高精度定位，目标检测，3D场景渲染等。
激光雷达测量产生的3D点云数据量巨大，这给点云数据存贮和传输带来巨大的挑战。为了降低点云数据的存储量，一般会将3D点云数据转化为2D点云数据作为定位图层。但是，位图层仍然覆盖了很大的地理区域，数据量仍然很大，点云数据中的图像编码得到的码流仍然会占用很大的存储开销。
发明内容
本申请提供一种图像编码方法、解码方法、装置和存储介质，以减少码流占用的存储空间。
第一方面，提供了一种图像解码方法，该方法包括：获取码流；根据码流，获取图像序列中的网格图像的残差图像；对图像序列中的网格图像进行帧间预测，得到图像序列中的网格图像的预测图像；根据图像序列中的网格图像的残差图像和图像序列中的网格图像的预测图像，得到图像序列中的网格图像。
其中，上述图像序列包括多个网格图像，该多个网格图像对应的地理位置相近或者该多个网格图像的图像内容相近。具体地，上述多个网格图像对应的地理位置相近或者该多个网格图像的图像内容相近可以是指上述多个网格图像满足第一条件。
应理解，上述对图像序列中的网格图像进行帧间预测，可以是先对网格图像进行预测，得到网格图像的残差图像，然后再将网格图像与该网格图像的残差图像进行做差，得到该网格图像的残差图像。
另外，在对图像序列中的网格图像进行帧间预测时，也可以是先将图像序列中的网格图像划分成图像块，然后采用帧间预测的方式确定每个图像块的预测块，进而确定每个图像块的残差块。本申请中，上述网格图像的预测图像可以是由网格图像中的各个图像块的 预测块组成，网格图像的残差图像可以由网格图像中的各个图像块的残差块组成。
本申请中，由于图像序列中包含地理位置相近或者图像内容相近的网格图像，因此，在对该图像序列进行帧间预测时，能够使得得到的残差图像的数据量较小，进而使得最终图像序列对应的码流占用的存储空间较小，便于存储或者传输。
结合第一方面，在第一方面的某些实现方式中，上述第一条件为多个网格图像中的至少两个网格图像对应的地理位置之间的间距小于预设距离。
上述预设距离也可以成为距离阈值，该预设距离的大小可以根据实际需要来灵活设置。例如，上述预设距离可以设置为3m(3米)，当两个网格图像的对应的地理位置之间的间距小于3m时，这两个网格图像满足第一条件。这里的3m仅仅为示例，预设距离还可以设置成5m和6m等等，总之可以根据需要设置任何合适大小的预设距离。
另外，上述第一条件还可以是多个网格图像中的至少两个网格图像对应的地理位置之间的间距小于或者等于预设距离。
由于地理位置相近的图像的相似度一般比较高，因此，当图像序列中包含对应地理位置相邻的至少两个网格图像时，通过对该图像序列进行帧间预测，能够使得后续得到的残差图像的数据量较小。
结合第一方面，在第一方面的某些实现方式中，上述第一条件为多个网格图像中的至少两个网格图像的图像内容的相似度大于或者等于预设相似度。
上述预设相似度还可以称为相似度阈值，该预设相似度的大小可以根据实际需要来灵活设置。例如，上述预设相似度可以设置为50％，当两个网格图像的图像内容的相似度大于或者等于50％时，这两个网格图像满足第一条件。这里的50％仅仅为示例，预设相似度还可以设置成55％，60％以及65％等等，总之可以根据需要设置任何合适大小的预设相似度。
另外，上述第一条件还可以是多个网格图像中的至少两个网格图像的图像内容的相似度大于预设相似度。
当图像序列中包含图像内容相近的至少两个网格图像时，通过对该图像序列进行帧间预测，能够使得后续得到的残差图像的数据量较小。
结合第一方面，在第一方面的某些实现方式中，上述第一条件为多个网格图像中的至少两个网格图像的图像内容对应于同一地理区域。
由于同一地理区域的图像的相似度一般会比较高，因此，当图像序列中包含位于同一地理区域的至少两个网格图像时，通过对该图像序列进行帧间预测，能够使得后续得到的残差图像的数据量较小。
上述地理区域的大小可以是预设大小，该地理区域的大小可以根据实际需要来设定。例如，上述地理区域的大小可以是2m×2m的区域。应理解，这里的2m×2m的区域的地理区域大小仅仅为示例，地理区域的大小还可能设置为1m×1m的区域，3m×32m的区域等等，总之可以根据需要设置任何合适大小的地理区域。
再如，上述地理区域的大小为2m×2m的区域，当两个网格图像均位于2m×2m的区域时，这两个网格图像满足第一条件。
结合第一方面，在第一方面的某些实现方式中，上述多个网格图像中的至少两个网格图像彼此之间为相邻帧的网格图像。
也就是说，上述满足第一条件的至少两个网格图像彼此之间为相邻帧。
例如，上述图像序列中的网格图像1、网格图像2和网格图像3满足上述第一条件。那么，网格图像1，网格图像2和网格图像3可以分别是图像序列中的第i帧，第i+1帧和第i+2帧。其中，i为正整数。
结合第一方面，在第一方面的某些实现方式中，上述图像序列中的网格图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，上述方法还包括：对图像序列中的网格图像进行处理，得到处理后的网格图像。
其中，图像序列中的网格图像的像素值的N个比特中第i个比特的取值，与处理后的图像序列中的网格图像的像素值的N个比特中的第i个比特的取值相反，图像序列中的网格图像的像素值的N个比特与处理后的图像序列中的网格图像的像素值的N个比特所处的位置相同。
图像序列中的网格图像的像素值的N个比特位于图像序列中的网格图像的像素值的第一比特之后并且与第一比特相邻，第一比特是图像序列中的网格图像的像素值中取值为1并且位数最高的比特位，i和N均为正整数，i≤N，N＜M。
在本申请中，编码端通过对网格图像的像素值进行取反处理，能够在网格图像的像素值包含连续的占位符的情况下，降低网格图像的数据量，进而使得编码生成的码流占用更少的存储空间，而解码端通过对解码得到的网格图像进行(取反)处理，从而能够将编码端处理(取反处理)过的网格图像进行还原，进而获得最终的网格图像。
结合第一方面，在第一方面的某些实现方式中，上述图像序列中的网格图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，上述方法还包括：对图像序列中的网格图像进行处理，得到处理后的网格图像。
其中，处理后的图像序列中的网格图像的N个比特中的第1个比特的取值与图像序列中的网格图像的N个比特中的第1个比特的取值相反，处理后的图像序列中的网格图像的N个比特中的第i+1个比特的取值是图像序列中的网格图像的N个比特中的第i+1个比特的取值与处理后的图像序列中的网格图像的N个比特中的第i个比特进行异或处理的结果。
图像序列中的网格图像的像素值的N个比特位于图像序列中的网格图像的像素值的第一比特之后并且与第一比特相邻，第一比特是图像序列中的网格图像的像素值中取值为1并且位数最高的比特位，或者，图像序列中的网格图像的像素值的N个比特位于图像序列中的网格图像的像素值的最高比特位之后并且与图像序列中的网格图像的像素值的最高比特位相邻。
图像序列中的网格图像的像素值的N个比特与处理后的图像序列中的网格图像的像素值的N个比特所处的位置相同，第i个比特的位数高于第i+1个比特的位数，i和N均为正整数，i≤N，N＜M。
本申请中，编码端通过对网格图像的像素值进行异或处理，能够在网格图像的像素值包含连续的占位符的情况下，降低网格图像的数据量，进而使得编码生成的码流占用更少的存储空间，而解码端通过对解码得到的网格图像进行(异或)处理，从而能够将编码端处理(异或处理)过的网格图像进行还原，进而获得最终的网格图像。
结合第一方面，在第一方面的某些实现方式中，上述残差图像的像素值采用M个比 特表示，每个比特的取值为0或1，M为大于1的整数，上述根据图像序列中的网格图像的残差图像和图像序列中的网格图像的预测图像，得到图像序列中的网格图像，具体包括：对残差图像进行处理，得到处理后的残差图像；根据处理后的残差图像和图像序列中的网格图像的预测图像，得到图像序列中的网格图像。
其中，上述残差图像的像素值的N个比特中的第i个比特的取值，与处理后的残差图像的像素值的N个比特中的第i个比特的取值相反，残差图像的像素值的N个比特与处理后的残差图像的像素值的N个比特所处的位置相同。
残差图像的像素值的N个比特位于残差图像的像素值的第一比特之后并且与第一比特相邻，第一比特是残差图像的像素值中取值为1并且位数最高的比特位，i和N均为正整数，i≤N，N＜M。
本申请中，编码端通过对残差图像的像素值进行取反处理，能够在残差图像的像素值包含连续的占位符的情况下，降低残差图像的数据量，进而使得编码生成的码流占用更少的存储空间，而解码端通过对解码得到的残差图像进行(取反)处理，从而能够将编码端处理(取反处理)过的残差图像进行还原，进而根据该处理后的残差图像得到最终的图像块。
结合第一方面，在第一方面的某些实现方式中，上述残差图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，上述根据图像序列中的网格图像的残差图像和图像序列中的网格图像的预测图像，得到图像序列中的网格图像，包括：对残差图像进行处理，得到处理后的残差图像；根据处理后的残差图像和图像序列中的网格图像的预测图像，得到图像序列中的网格图像。
其中，上述处理后的残差图像的N个比特中的第1个比特的取值与残差图像的N个比特中的第1个比特的取值相反，处理后的残差图像的N个比特中的第i+1个比特的取值是残差图像的N个比特中的第i+1个比特的取值与处理后的残差图像的N个比特中的第i个比特进行异或处理的结果。
残差图像的像素值的N个比特位于残差图像的像素值的第一比特之后并且与第一比特相邻，第一比特是残差图像的像素值中取值为1并且位数最高的比特位，或者，残差图像的像素值的N个比特位于残差图像的像素值的最高比特位之后并且与残差图像的像素值的最高比特位相邻。
残差图像的像素值的N个比特与处理后的残差图像的像素值的N个比特所处的位置相同，第i个比特的位数高于第i+1个比特的位数，i和N均为正整数，i≤N，N＜M；
本申请中，编码端通过对残差图像的像素值进行异或处理，能够在残差图像的像素值包含连续的占位符的情况下，降低残差图像的数据量，进而使得编码生成的码流占用更少的存储空间，而解码端通过对解码得到的残差图像进行(异或)处理，从而能够将编码端处理(异或处理)过的残差图像进行还原，进而根据该处理后的残差图像得到最终的图像块。
结合第一方面，在第一方面的某些实现方式中，上述根据码流，获取图像序列中的网格图像的残差图像，包括：对码流进行反变换、反量化和熵解码处理，得到残差图像。
上述解码处理对应于图像的有损编码，这种方式能够使得编码得到的码流尽可能的占用较小的存储空间。
结合第一方面，在第一方面的某些实现方式中，上述根据码流，获取图像序列中的网格图像的残差图像，包括：对码流进行熵解码处理，得到残差图像。
上述仅进行熵解码处理的解码方式对应于无损编码，这种编码方式能够尽可能的避免图像失真，保证图像最终的显示效果。
结合第一方面，在第一方面的某些实现方式中，上述码流是对定位图层进行编码得到的。
结合第一方面，在第一方面的某些实现方式中，上述定位图层的像素值包含栅格化后的高程数据。
上述定位图层的像素值包含M个比特，每个比特表示每个栅格的占有位。由于定位图层的像素值中包含栅格化后的高程数据，而高程数据中高位出现字符“11”的概率比较高，因此，通过对包含高程数据的定位图层的像素值进行处理，能够降低定位图层的像素值的数据量，进而减少最终得到的码流占用的存储空间。
结合第一方面，在第一方面的某些实现方式中，上述M的取值为8、10和12中的任意一个。
第二方面，提供了一种图像编码方法，该方法包括：获取图像序列；对图像序列中的网格图像进行帧间预测，得到残差图像；对残差图像进行编码，得到编码码流。
其中，上述图像序列包括多个网格图像，该多个网格图像对应的地理位置相近或者该多个网格图像的图像内容相近。具体地，上述多个网格图像对应的地理位置相近或者该多个网格图像的图像内容相近可以是指上述多个网格图像满足第一条件。
应理解，上述对图像序列中的网格图像进行帧间预测，可以是先对网格图像进行预测，得到网格图像的残差图像，然后再将网格图像与该网格图像的残差图像进行做差，得到该网格图像的残差图像。
具体地，上述网格图像的预测图像可以是由网格图像中的各个图像块的预测块组成，网格图像的残差图像可以由网格图像中的各个图像块的残差块组成。在编码端进行编码时，可以将残差图像划分成图像块，然后获取每个图像块的预测块，并根据每个图像块和每个图像块的残差块，得到每个图像块的残差块，进而得到网格图像的残差图像。
本申请中，由于图像序列中包含地理位置相近或者图像内容相近的网格图像，因此，在对该图像序列进行帧间预测时，能够使得得到的残差图像的数据量较小，进而使得最终对图像序列进行编码得到的码流占用的存储空间较小，便于存储或者传输。
结合第二方面，在第二方面的某些实现方式中，上述第一条件为多个网格图像中的至少两个网格图像对应的地理位置之间的间距小于预设距离。
上述预设距离也可以成为距离阈值，该预设距离的大小可以根据实际需要来灵活设置。
例如，上述预设距离可以设置为3m(3米)，当两个网格图像的对应的地理位置之间的间距小于3m时，这两个网格图像满足第一条件。这里的3m仅仅为示例，预设距离还可以设置成5m和6m等等，总之可以根据需要设置任何合适大小的预设距离。
另外，上述第一条件还可以是多个网格图像中的至少两个网格图像对应的地理位置之间的间距小于或者等于预设距离。
由于地理位置相近的图像的相似度一般比较高，因此，当图像序列中包含对应地理位 置相邻的至少两个网格图像时，通过对该图像序列进行帧间预测，能够使得后续得到的残差图像的数据量较小。
结合第二方面，在第二方面的某些实现方式中，上述第一条件为多个网格图像中的至少两个网格图像的图像内容的相似度大于或者等于预设相似度。
当图像序列中包含图像内容相近的至少两个网格图像时，通过对该图像序列进行帧间预测，能够使得后续得到的残差图像的数据量较小。
上述预设相似度还可以称为相似度阈值，该预设相似度的大小可以根据实际需要来灵活设置。
例如，上述预设相似度可以设置为50％，当两个网格图像的图像内容的相似度大于或者等于50％时，这两个网格图像满足第一条件。这里的50％仅仅为示例，预设相似度还可以设置成55％，60％以及65％等等，总之可以根据需要设置任何合适大小的预设相似度。
另外，上述第一条件还可以是多个网格图像中的至少两个网格图像的图像内容的相似度大于预设相似度。
当图像序列中包含图像内容相近的至少两个网格图像时，通过对该图像序列进行帧间预测，能够使得后续得到的残差图像的数据量较小。
结合第二方面，在第二方面的某些实现方式中，上述第一条件为图像序列中的至少两个网格图像的图像内容对应于同一地理区域。
由于同一地理区域的图像的相似度一般会比较高，因此，当图像序列中包含位于同一地理区域的至少两个网格图像时，通过对该图像序列进行帧间预测，能够使得后续得到的残差图像的数据量较小。
上述地理区域的大小可以是预设大小，该地理区域的大小可以根据实际需要来设定。例如，上述地理区域的大小可以是2m×2m的区域。应理解，这里的2m×2m的区域的地理区域大小仅仅为示例，地理区域的大小还可能设置为1m×1m的区域，3m×32m的区域等等，总之可以根据需要设置任何合适大小的地理区域。
再如，上述地理区域的大小为2m×2m的区域，当两个网格图像均位于2m×2m的区域时，这两个网格图像满足第一条件。
结合第二方面，在第二方面的某些实现方式中，上述多个网格图像中的至少两个网格图像彼此间为相邻帧的网格图像。
应理解，上述满足第一条件的至少两个网格图像彼此之间可以为相邻帧。例如，上述图像序列中的网格图像1、网格图像2和网格图像3满足上述第一条件。那么，网格图像1，网格图像2和网格图像3可以分别是图像序列中的第i帧，第i+1帧和第i+2帧。其中，i为正整数。
结合第二方面，在第二方面的某些实现方式中，图像序列中的网格图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，在对图像序列中的网格图像进行帧间预测之前，上述方法还包括：对图像序列中的网格图像进行处理，得到处理后的网格图像；对图像序列中的网格图像进行帧间预测，包括：对处理后的网格图像进行帧间预测，得到残差图像。
其中，图像序列中的网格图像的像素值的N个比特中第i个比特的取值，与处理后的图像序列中的网格图像的像素值的N个比特中的第i个比特的取值相反，图像序列中的网 格图像的像素值的N个比特与处理后的图像序列中的网格图像的像素值的N个比特所处的位置相同。
图像序列中的网格图像的像素值的N个比特位于图像序列中的网格图像的像素值的第一比特之后并且与第一比特相邻，第一比特是图像序列中的网格图像的像素值中取值为1并且位数最高的比特位，i和N均为正整数，i≤N，N＜M。
本申请中，编码端通过对网格图像的像素值进行取反处理，能够在网格图像的像素值包含连续的占位符的情况下，降低网格图像的数据量，进而使得编码生成的码流占用更少的存储空间。
结合第二方面，在第二方面的某些实现方式中，图像序列中的网格图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，在对图像序列中的网格图像进行帧间预测之前，上述方法还包括：对图像序列中的网格图像进行处理，得到处理后的网格图像；对图像序列中的网格图像进行帧间预测，包括：对处理后的网格图像进行帧间预测，得到残差图像。
其中，处理后的图像序列中的网格图像的N个比特中的第1个比特的取值与图像序列中的网格图像的N个比特中的第1个比特的取值相反，处理后的图像序列中的网格图像的N个比特中的第i+1个比特的取值是图像序列中的网格图像的N个比特中的第i+1个比特的取值与处理后的图像序列中的网格图像的N个比特中的第i个比特进行异或处理的结果。
图像序列中的网格图像的像素值的N个比特位于图像序列中的网格图像的像素值的第一比特之后并且与第一比特相邻，第一比特是图像序列中的网格图像的像素值中取值为1并且位数最高的比特位，或者，图像序列中的网格图像的像素值的N个比特位于图像序列中的网格图像的像素值的最高比特位之后并且与图像序列中的网格图像的像素值的最高比特位相邻。
图像序列中的网格图像的像素值的N个比特与处理后的图像序列中的网格图像的像素值的N个比特所处的位置相同，第i个比特的位数高于第i+1个比特的位数，i和N均为正整数，i≤N，N＜M。
本申请中，编码端通过对网格图像的像素值进行异或处理，能够在网格图像的像素值包含连续的占位符的情况下，降低网格图像的数据量，进而使得编码生成的码流占用更少的存储空间。
结合第二方面，在第二方面的某些实现方式中，残差图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，其特征在于，上述对残差图像进行编码，得到编码码流，包括：对残差图像进行处理，得到处理后的残差图像；对处理后的残差图像进行编码，得到编码码流。
其中，残差图像的像素值的N个比特中的第i个比特的取值，与处理后的残差图像的像素值的N个比特中的第i个比特的取值相反，残差图像的像素值的N个比特与处理后的残差图像的像素值的N个比特所处的位置相同，
残差图像的像素值的N个比特位于残差图像的像素值的第一比特之后并且与第一比特相邻，第一比特是残差图像的像素值中取值为1并且位数最高的比特位，i和N均为正整数，i≤N，N＜M。
本申请实施例中，编码端通过对残差图像的像素值进行异或处理，能够在残差图像的像素值包含连续的占位符的情况下，降低残差图像的数据量，进而使得编码生成的码流占用更少的存储空间。
结合第二方面，在第二方面的某些实现方式中，残差图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，其特征在于，上述对残差图像进行编码，得到编码码流，包括：对残差图像进行处理，得到处理后的残差图像；对处理后的残差图像进行编码，得到编码码流。
其中，残差图像的像素值的N个比特中第i个比特的取值，与处理后的残差图像的像素值的N个比特中的第i个比特的取值相反，处理后的残差图像的N个比特中的第i+1个比特的取值是残差图像的N个比特中的第i+1个比特的取值与处理后的残差图像的N个比特中的第i个比特进行异或处理的结果。
残差图像的像素值的N个比特位于残差图像的像素值的第一比特之后并且与第一比特相邻，第一比特是残差图像的像素值中取值为1并且位数最高的比特位，或者，残差图像的像素值的N个比特位于残差图像的像素值的最高比特位之后并且与残差图像的像素值的最高比特位相邻。
残差图像的像素值的N个比特与处理后的残差图像的像素值的N个比特所处的位置相同，第i个比特的位数高于第i+1个比特的位数，i和N均为正整数，i≤N，N＜M。
本申请实施例中，编码端通过对残差图像的像素值进行异或处理，能够在残差图像的像素值包含连续的占位符的情况下，降低残差图像的数据量，进而使得编码生成的码流占用更少的存储空间。
结合第二方面，在第二方面的某些实现方式中，对残差图像进行编码，得到编码码流，包括：对残差图像进行变换、量化和熵编码处理，得到编码码流。
通过采用有损编码，能够使得编码得到的码流尽可能的占用较小的存储空间。
结合第二方面，在第二方面的某些实现方式中，对残差图像进行编码，得到编码码流，包括：对残差图像进行熵编码处理，得到编码码流。
通过采用无损编码，能够尽可能的避免图像失真，保证图像最终的显示效果。
结合第二方面，在第二方面的某些实现方式中，上述图像序列中的网格图片来自定位图层。
结合第二方面，在第二方面的某些实现方式中，上述定位图层的像素值包含栅格化后的高程数据。
上述定位图层的像素值包含M个比特，每个比特表示每个栅格的占有位。由于定位图层的像素值中包含栅格化后的高程数据，而高程数据中高位出现字符“11”的概率比较高，因此，通过对包含高程数据的定位图层的像素值进行处理，能够降低定位图层的像素值的数据量，进而减少最终得到的码流占用的存储空间。
结合第二方面，在第二方面的某些实现方式中，M的取值为8、10和12中的任意一个。
第三方面，提供了一种图像解码装置，该装置包括与上述第一方面的方法对应的模块，该对应的模块能够实现上述第一方面的方法的各个步骤。
第四方面，提供了一种图像编码装置，该装置包括与上述第二方面的方法对应的模块， 该对应的模块能够实现上述第二方面的方法的各个步骤。
上述第三方面中的图像解码装置或者上述第四方面中的图像编码装置可以包含一个或者多个模块，该一个或者多个模块中的任意一个模块可以由电路、现场可编程门阵列FPGA、特殊应用集成电路ASIC以及通用处理器中的任意一种构成。
第五方面，提供了一种图像解码装置，包括存储器和处理器，所述处理器调用存储在所述存储器中的程序代码以执行第一方面的方法。
第六方面，提供了一种图像编码装置，包括存储器和处理器，所述处理器调用存储在所述存储器中的程序代码以执行第二方面的方法。
可选地，上述存储器为非易失性存储器。
可选地，上述存储器与处理器互相耦合在一起。
上述图像解码装置也可以称为图像解码器，上述图像编码装置也可以称为图像编码器。
第七方面，本申请实施例提供一种计算机可读存储介质，所述计算机可读存储介质存储有指令，所述指令使得一个或多个处理器执行第一方面或第二方面中的方法。
上述一个或者多个处理器中的任意一个处理器可以由电路、现场可编程门阵列FPGA、特殊应用集成电路ASIC以及通用处理器中的任意一种构成。
第八方面，本申请实施例提供一种计算机程序产品，当所述计算机程序产品在计算机上运行时，使得所述计算机执行第一方面或第二方面中的方法的部分或全部步骤。
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图1是用于实现本申请实施例的视频编码***实例的示意性框图；
图2是用于实现本申请实施例的视频编码器实例的示意性结构框图；
图3是用于实现本申请实施例的视频解码器实例的示意性结构框图；
图4是用于实现本申请实施例的视频译码***实例的示意性结构框图；
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图8是本申请实施例的图像编码方法的过程的示意图；
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图10是本申请实施例的图像编码方法的过程的示意图；
图11是本申请实施例的图像解码方法的示意性流程图；
图12是本申请实施例的图像解码方法的示意性流程图；
图13是本申请实施例的图像解码方法的示意性流程图；
图14是本申请实施例的图像编码方法的示意性流程图；
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图16是采用取反操作对应的编码性能的示意图；
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图19是图像序列中包含I帧和P帧的示意图；
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具体实施方式
下面将结合附图，对本申请中的技术方案进行描述。
在以下描述中，将会参考形成本申请一部分并以说明之方式示出本申请实施例的具体方面或可使用本申请实施例的具体方面的附图。应理解，本申请实施例还可以在在其它方面中使用，并且可以包括附图中未描绘的结构或逻辑变化。因此，以下详细描述不应以限制性的意义来理解，本申请的范围应由所附权利要求书界定。
例如，应理解，结合所描述方法的揭示内容可以同样适用于执行所述方法的对应设备或***，反之亦然。
再如，如果描述一个或多个具体方法步骤，则对应的设备可以包含如功能单元等一个或多个单元，来执行所描述的一个或多个方法步骤(例如，一个单元执行一个或多个步骤，或多个单元，其中每个都执行多个步骤中的一个或多个)，即使附图中未明确描述或说明这种一个或多个单元。
此外，如果基于如功能单元等一个或多个单元描述具体装置，则对应的方法可以包含一个步骤来执行一个或多个单元的功能(例如，一个步骤执行一个或多个单元的功能，或多个步骤，其中每个执行多个单元中一个或多个单元的功能)，即使附图中未明确描述或说明这种一个或多个步骤。进一步，应理解的是，除非另外明确提出，本文中所描述的各示例性实施例和/或方面的特征可以相互组合。
本申请实施例所涉及的技术方案可以应用于H.266标准以及未来的视频编码标准中。本申请的实施方式部分使用的术语仅用于对本申请的具体实施例进行解释，而非旨在限定本申请。下面先对本申请实施例可能涉及的一些概念进行简单介绍。
本申请中的图像编码和解码与视频图像的编码和解码相同，下面对视频图像的编码和解码的一些基本过程和相关内容进行详细的介绍。
视频编码通常是指处理形成视频或视频序列的图片序列。在视频编码领域，术语“图片(picture)”、“帧(frame)”或“图像(image)”可以用作同义词。本文中使用的视频编码表示视频编码或视频解码。视频编码在源侧执行，通常包括处理(例如，通过压缩)原始视频图片以减少表示该视频图片所需的数据量，从而更高效地存储和/或传输。视频解码在目的地侧执行，通常包括相对于编码器作逆处理，以重构视频图片。实施例涉及的视频图片“编码”应理解为涉及视频序列的“编码”或“解码”。编码部分和解码部分的组合也称为编解码(编码和解码)。
视频序列包括一系列图像(picture)，图像被进一步划分为切片(slice)，切片再被划分为块(block)。视频编码以块为单位进行编码处理，在一些新的视频编码标准中，块的概念被进一步扩展。比如，在H.264标准中有宏块(macroblock，MB)，宏块可进一步划分成多个可用于预测编码的预测块(partition)。在高性能视频编码(high efficiency  video coding，HEVC)标准中，采用编码单元(coding unit，CU)，预测单元(prediction unit，PU)和变换单元(transform unit，TU)等基本概念，从功能上划分了多种块单元，并采用全新的基于树结构进行描述。比如CU可以按照四叉树进行划分为更小的CU，而更小的CU还可以继续划分，从而形成一种四叉树结构，CU是对编码图像进行划分和编码的基本单元。对于PU和TU也有类似的树结构，PU可以对应预测块，是预测编码的基本单元。对CU按照划分模式进一步划分成多个PU。TU可以对应变换块，是对预测残差进行变换的基本单元。然而，无论CU，PU还是TU，本质上都属于块(或称图像块)的概念。
例如，在HEVC中，通过使用表示为编码树的四叉树结构将CTU拆分为多个CU。在CU层级处作出是否使用图片间(时间)或图片内(空间)预测对图片区域进行编码的决策。每个CU可以根据PU拆分类型进一步拆分为一个、两个或四个PU。一个PU内应用相同的预测过程，并在PU基础上将相关信息传输到解码器。在通过基于PU拆分类型应用预测过程获取残差块之后，可以根据类似于用于CU的编码树的其它四叉树结构将CU分割成变换单元(transform unit，TU)。在视频压缩技术最新的发展中，使用四叉树和二叉树(quad-tree and binary tree，QTBT)分割帧来分割编码块。在QTBT块结构中，CU可以为正方形或矩形形状。
本文中，为了便于描述和理解，可将当前编码图像中待编码的图像块称为当前图像块，例如在编码中，指当前正在编码的块；在解码中，指当前正在解码的块。将参考图像中用于对当前图像块进行预测的已解码的图像块称为参考块，即参考块是为当前图像块提供参考信号的块，其中，参考信号表示图像块内的像素值。可将参考图像中为当前图像块提供预测信号的块为预测块，其中，预测信号表示预测块内的像素值或者采样值或者采样信号。例如，在遍历多个参考块以后，找到了最佳参考块，此最佳参考块将为当前图像块提供预测，此块称为预测块。
无损视频编码情况下，可以重构原始视频图片，即经重构视频图片具有与原始视频图片相同的质量(假设存储或传输期间没有传输损耗或其它数据丢失)。在有损视频编码情况下，通过例如量化执行进一步压缩，来减少表示视频图片所需的数据量，而解码器侧无法完全重构视频图片，即经重构视频图片的质量相比原始视频图片的质量较低或较差。
H.261的几个视频编码标准属于“有损混合型视频编解码”(即，将样本域中的空间和时间预测与变换域中用于应用量化的2D变换编码结合)。视频序列的每个图片通常分割成不重叠的块集合，通常在块层级上进行编码。换句话说，编码器侧通常在块(视频块)层级处理亦即编码视频，例如，通过空间(图片内)预测和时间(图片间)预测来产生预测块，从当前图像块(当前处理或待处理的块)减去预测块以获取残差块，在变换域变换残差块并量化残差块，以减少待传输(压缩)的数据量，而解码器侧将相对于编码器的逆处理部分应用于经编码或经压缩块，以重构用于表示的当前图像块。另外，编码器复制解码器处理循环，使得编码器和解码器生成相同的预测(例如帧内预测和帧间预测)和/或重构，用于处理亦即编码后续块。
下面描述本申请实施例所应用的***架构。参见图1，图1示例性地给出了本申请实施例所应用的视频编码及解码***10的示意性框图。如图1所示，视频编码及解码***10可包括源设备12和目的地设备14，源设备12产生经编码视频数据，因此，源设备12 可被称为视频编码装置。目的地设备14可对由源设备12所产生的经编码的视频数据进行解码，因此，目的地设备14可被称为视频解码装置。源设备12、目的地设备14或两个的各种实施方案可包含一个或多个处理器以及耦合到所述一个或多个处理器的存储器。所述存储器可包含但不限于只读存储器(read-only memory，ROM)、随机存取存储器(random access memory，RAM)、可擦写可编程只读存储器(erasable programmable read-only memory，EPROM)、快闪存储器或可用于以可由计算机存取的指令或数据结构的形式存储所要的程序代码的任何其它媒体，如本文所描述。源设备12和目的地设备14可以包括各种装置，包含桌上型计算机、移动计算装置、笔记型(例如，膝上型)计算机、平板计算机、机顶盒、例如所谓的“智能”电话等电话手持机、电视机、相机、显示装置、数字媒体播放器、视频游戏控制台、车载计算机、无线通信设备或其类似者。
虽然图1将源设备12和目的地设备14绘示为单独的设备，但设备实施例也可以同时包括源设备12和目的地设备14或同时包括两者的功能，即源设备12或对应的功能以及目的地设备14或对应的功能。在此类实施例中，可以使用相同硬件和/或软件，或使用单独的硬件和/或软件，或其任何组合来实施源设备12或对应的功能性以及目的地设备14或对应的功能性。
源设备12和目的地设备14之间可通过链路13进行通信连接，目的地设备14可经由链路13从源设备12接收经编码视频数据。链路13可包括能够将经编码视频数据从源设备12移动到目的地设备14的一个或多个媒体或装置。在一个实例中，链路13可包括使得源设备12能够实时将经编码视频数据直接发射到目的地设备14的一个或多个通信媒体。在此实例中，源设备12可根据通信标准(例如无线通信协议)来调制经编码视频数据，且可将经调制的视频数据发射到目的地设备14。所述一个或多个通信媒体可包含无线和/或有线通信媒体，例如射频(RF)频谱或一个或多个物理传输线。所述一个或多个通信媒体可形成基于分组的网络的一部分，基于分组的网络例如为局域网、广域网或全球网络(例如，因特网)。所述一个或多个通信媒体可包含路由器、交换器、基站或促进从源设备12到目的地设备14的通信的其它设备。
源设备12包括编码器20，另外可选地，源设备12还可以包括图片源16、图片预处理器18、以及通信接口22。具体实现形态中，所述编码器20、图片源16、图片预处理器18、以及通信接口22可能是源设备12中的硬件部件，也可能是源设备12中的软件程序。分别描述如下：
图片源16，可以包括或可以为任何类别的图片捕获设备，用于例如捕获现实世界图片，和/或任何类别的图片或评论(对于屏幕内容编码，屏幕上的一些文字也认为是待编码的图片或图像的一部分)生成设备，例如，用于生成计算机动画图片的计算机图形处理器，或用于获取和/或提供现实世界图片、计算机动画图片(例如，屏幕内容、虚拟现实(virtual reality，VR)图片)的任何类别设备，和/或其任何组合(例如，实景(augmented reality，AR)图片)。图片源16可以为用于捕获图片的相机或者用于存储图片的存储器，图片源16还可以包括存储先前捕获或产生的图片和/或获取或接收图片的任何类别的(内部或外部)接口。当图片源16为相机时，图片源16可例如为本地的或集成在源设备中的集成相机；当图片源16为存储器时，图片源16可为本地的或例如集成在源设备中的集成存储器。当所述图片源16包括接口时，接口可例如为从外部视频源接收图片的外部接口， 外部视频源例如为外部图片捕获设备，比如相机、外部存储器或外部图片生成设备，外部图片生成设备例如为外部计算机图形处理器、计算机或服务器。接口可以为根据任何专有或标准化接口协议的任何类别的接口，例如有线或无线接口、光接口。
其中，图片可以视为像素点(picture element)的二维阵列或矩阵。阵列中的像素点也可以称为采样点。阵列或图片在水平和垂直方向(或轴线)上的采样点数目定义图片的尺寸和/或分辨率。为了表示颜色，通常采用三个颜色分量，即图片可以表示为或包含三个采样阵列。例如在RBG格式或颜色空间中，图片包括对应的红色、绿色及蓝色采样阵列。但是，在视频编码中，每个像素通常以亮度/色度格式或颜色空间表示，例如对于YUV格式的图片，包括Y指示的亮度分量(有时也可以用L指示)以及U和V指示的两个色度分量。亮度(luma)分量Y表示亮度或灰度水平强度(例如，在灰度等级图片中两者相同)，而两个色度(chroma)分量U和V表示色度或颜色信息分量。相应地，YUV格式的图片包括亮度采样值(Y)的亮度采样阵列，和色度值(U和V)的两个色度采样阵列。RGB格式的图片可以转换或变换为YUV格式，反之亦然，该过程也称为色彩变换或转换。如果图片是黑白的，该图片可以只包括亮度采样阵列。本申请实施例中，由图片源16传输至图片处理器的图片也可称为原始图片数据17。
图片预处理器18，用于接收原始图片数据17并对原始图片数据17执行预处理，以获取经预处理的图片19或经预处理的图片数据19。例如，图片预处理器18执行的预处理可以包括整修、色彩格式转换(例如，从RGB格式转换为YUV格式)、调色或去噪。
编码器20(或称视频编码器20)，用于接收经预处理的图片数据19，采用相关预测模式(如本文各个实施例中的预测模式)对经预处理的图片数据19进行处理，从而提供经编码图片数据21(下文将进一步基于图2或图4或图5描述编码器20的结构细节)。在一些实施例中，编码器20可以用于执行后文所描述的各个实施例，以实现本申请所描述的编码方法在编码侧的应用。
通信接口22，可用于接收经编码图片数据21，并可通过链路13将经编码图片数据21传输至目的地设备14或任何其它设备(如存储器)，以用于存储或直接重构，所述其它设备可为任何用于解码或存储的设备。通信接口22例如可用于将经编码图片数据21封装成合适的格式，例如数据包，以在链路13上传输。
目的地设备14包括解码器30，另外可选地，目的地设备14还可以包括通信接口28、图片后处理器32和显示设备34。分别描述如下：
通信接口28，可用于从源设备12或任何其它源接收经编码图片数据21，所述任何其它源例如为存储设备，存储设备例如为经编码图片数据存储设备。通信接口28可以用于藉由源设备12和目的地设备14之间的链路13或经由任何类别的网络传输或接收经编码图片数据21，链路13例如为直接有线或无线连接，任何类别的网络例如为有线或无线网络或其任何组合，或任何类别的私网和公网，或其任何组合。通信接口28可以例如用于解封装通信接口22所传输的数据包以获取经编码图片数据21。
通信接口28和通信接口22都可以配置为单向通信接口或者双向通信接口，以及可以用于例如发送和接收消息来建立连接、确认和交换任何其它与通信链路和/或例如经编码图片数据传输的数据传输有关的信息。
解码器30(或称为解码器30)，用于接收经编码图片数据21并提供经解码图片数据 31或经解码图片31(下文将进一步基于图3或图4或图5描述解码器30的结构细节)。在一些实施例中，解码器30可以用于执行后文所描述的各个实施例，以实现本申请所描述的解码方法在解码侧的应用。
图片后处理器32，用于对经解码图片数据31(也称为经重构图片数据)执行后处理，以获得经后处理图片数据33。图片后处理器32执行的后处理可以包括：色彩格式转换(例如，从YUV格式转换为RGB格式)、调色、整修或重采样，或任何其它处理，还可用于将将经后处理图片数据33传输至显示设备34。
显示设备34，用于接收经后处理图片数据33以向例如用户或观看者显示图片。显示设备34可以为或可以包括任何类别的用于呈现经重构图片的显示器，例如，集成的或外部的显示器或监视器。例如，显示器可以包括液晶显示器(liquid crystal display，LCD)、有机发光二极管(organic light emitting diode，OLED)显示器、等离子显示器、投影仪、微LED显示器、硅基液晶(liquid crystal on silicon，LCoS)、数字光处理器(digital light processor，DLP)或任何类别的其它显示器。
虽然，图1中将源设备12和目的地设备14绘示为单独的设备，但设备实施例也可以同时包括源设备12和目的地设备14或同时包括两者的功能性，即源设备12或对应的功能性以及目的地设备14或对应的功能性。在此类实施例中，可以使用相同硬件和/或软件，或使用单独的硬件和/或软件，或其任何组合来实施源设备12或对应的功能性以及目的地设备14或对应的功能性。
本领域技术人员基于描述明显可知，不同单元的功能性或图1所示的源设备12和/或目的地设备14的功能性的存在和(准确)划分可能根据实际设备和应用有所不同。源设备12和目的地设备14可以包括各种设备中的任一个，包含任何类别的手持或静止设备，例如，笔记本或膝上型计算机、移动电话、智能手机、平板或平板计算机、摄像机、台式计算机、机顶盒、电视机、相机、车载设备、显示设备、数字媒体播放器、视频游戏控制台、视频流式传输设备(例如内容服务服务器或内容分发服务器)、广播接收器设备、广播发射器设备等，并可以不使用或使用任何类别的操作***。
编码器20和解码器30都可以实施为各种合适电路中的任一个，例如，一个或多个微处理器、数字信号处理器(digital signal processor，DSP)、专用集成电路(application-specific integrated circuit，ASIC)、现场可编程门阵列(field-programmable gate array，FPGA)、离散逻辑、硬件或其任何组合。如果部分地以软件实施所述技术，则设备可将软件的指令存储于合适的非暂时性计算机可读存储介质中，且可使用一个或多个处理器以硬件执行指令从而执行本申请的技术。前述内容(包含硬件、软件、硬件与软件的组合等)中的任一者可视为一个或多个处理器。
在一些情况下，图1中所示视频编码及解码***10仅为示例，本申请的技术可以适用于不必包含编码和解码设备之间的任何数据通信的视频编码设置(例如，视频编码或视频解码)。在其它实例中，数据可从本地存储器检索、在网络上流式传输等。视频编码设备可以对数据进行编码并且将数据存储到存储器，和/或视频解码设备可以从存储器检索数据并且对数据进行解码。在一些实例中，由并不彼此通信而是仅编码数据到存储器和/或从存储器检索数据且解码数据的设备执行编码和解码。
参见图2，图2示出用于实现本申请实施例的编码器20的实例的示意性/概念性框图。 在图2的实例中，编码器20包括残差计算单元204、变换处理单元206、量化单元208、逆量化单元210、逆变换处理单元212、重构单元214、缓冲器216、环路滤波器单元220、经解码图片缓冲器(decoded picture buffer，DPB)230、预测处理单元260和熵编码单元270。预测处理单元260可以包含帧间预测单元244、帧内预测单元254和模式选择单元262。帧间预测单元244可以包含运动估计单元和运动补偿单元(图中未示出)。图2所示的编码器20也可以称为混合型视频编码器或根据混合型视频编解码器的视频编码器。
例如，残差计算单元204、变换处理单元206、量化单元208、预测处理单元260和熵编码单元270形成编码器20的前向信号路径，而例如逆量化单元210、逆变换处理单元212、重构单元214、缓冲器216、环路滤波器220、经解码图片缓冲器(decoded picture buffer，DPB)230、预测处理单元260形成编码器的后向信号路径，其中编码器的后向信号路径对应于解码器的信号路径(参见图3中的解码器30)。
编码器20通过例如输入202，接收图片201或图片201的图像块203，例如，形成视频或视频序列的图片序列中的图片。图像块203也可以称为当前图片块或待编码图片块，图片201可以称为当前图片或待编码图片(尤其是在视频编码中将当前图片与其它图片区分开时，其它图片例如同一视频序列亦即也包括当前图片的视频序列中的先前经编码和/或经解码图片)。
编码器20的实施例可以包括分割单元(图2中未示出)，用于将图片201分割成多个例如图像块203的块，通常分割成多个不重叠的块。分割单元可以用于对视频序列中所有图片使用相同的块大小以及定义块大小的对应栅格，或用于在图片或子集或图片群组之间更改块大小，并将每个图片分割成对应的块。
在一个实例中，编码器20的预测处理单元260可以用于执行上述分割技术的任何组合。
如图片201，图像块203也是或可以视为具有采样值的采样点的二维阵列或矩阵，虽然其尺寸比图片201小。换句话说，图像块203可以包括，例如，一个采样阵列(例如黑白图片201情况下的亮度阵列)或三个采样阵列(例如，彩色图片情况下的一个亮度阵列和两个色度阵列)或依据所应用的色彩格式的任何其它数目和/或类别的阵列。图像块203的水平和垂直方向(或轴线)上采样点的数目定义图像块203的尺寸。
如图2所示的编码器20用于逐块编码图片201，例如，对每个图像块203执行编码和预测。
残差计算单元204用于基于图片图像块203和预测块265(下文提供预测块265的其它细节)计算残差块205，例如，通过逐样本(逐像素)将图片图像块203的样本值减去预测块265的样本值，以在样本域中获取残差块205。
变换处理单元206用于在残差块205的样本值上应用例如离散余弦变换(discrete cosine transform，DCT)或离散正弦变换(discrete sine transform，DST)的变换，以在变换域中获取变换系数207。变换系数207也可以称为变换残差系数，并在变换域中表示残差块205。
变换处理单元206可以用于应用DCT/DST的整数近似值，例如为HEVC/H.265指定的变换。与正交DCT变换相比，这种整数近似值通常由某一因子按比例缩放。为了维持经正变换和逆变换处理的残差块的范数，应用额外比例缩放因子作为变换过程的一部分。 比例缩放因子通常是基于某些约束条件选择的，例如，比例缩放因子是用于移位运算的2的幂、变换系数的位深度、准确性和实施成本之间的权衡等。例如，在解码器30侧通过例如逆变换处理单元212为逆变换(以及在编码器20侧通过例如逆变换处理单元212为对应逆变换)指定具体比例缩放因子，以及相应地，可以在编码器20侧通过变换处理单元206为正变换指定对应比例缩放因子。
量化单元208用于例如通过应用标量量化或向量量化来量化变换系数207，以获取经量化变换系数209。经量化变换系数209也可以称为经量化残差系数209。量化过程可以减少与部分或全部变换系数207有关的位深度。例如，可在量化期间将n位变换系数向下舍入到m位变换系数，其中n大于m。可通过调整量化参数(quantization parameter，QP)修改量化程度。例如，对于标量量化，可以应用不同的标度来实现较细或较粗的量化。较小量化步长对应较细量化，而较大量化步长对应较粗量化。可以通过量化参数(quantization parameter，QP)指示合适的量化步长。例如，量化参数可以为合适的量化步长的预定义集合的索引。例如，较小的量化参数可以对应精细量化(较小量化步长)，较大量化参数可以对应粗糙量化(较大量化步长)，反之亦然。量化可以包含除以量化步长以及例如通过逆量化210执行的对应的量化或逆量化，或者可以包含乘以量化步长。根据例如HEVC的一些标准的实施例可以使用量化参数来确定量化步长。一般而言，可以基于量化参数使用包含除法的等式的定点近似来计算量化步长。可以引入额外比例缩放因子来进行量化和反量化，以恢复可能由于在用于量化步长和量化参数的等式的定点近似中使用的标度而修改的残差块的范数。在一个实例实施方式中，可以合并逆变换和反量化的标度。或者，可以使用自定义量化表并在例如比特流中将其从编码器通过信号发送到解码器。量化是有损操作，其中量化步长越大，损耗越大。
逆量化单元210用于在经量化系数上应用量化单元208的逆量化，以获取经反量化系数211，例如，基于或使用与量化单元208相同的量化步长，应用量化单元208应用的量化方案的逆量化方案。经反量化系数211也可以称为经反量化残差系数211，对应于变换系数207，虽然由于量化造成的损耗通常与变换系数不相同。
逆变换处理单元212用于应用变换处理单元206应用的变换的逆变换，例如，逆离散余弦变换(discrete cosine transform，DCT)或逆离散正弦变换(discrete sine transform，DST)，以在样本域中获取逆变换块213。逆变换块213也可以称为逆变换经反量化块213或逆变换残差块213。
重构单元214(例如，求和器214)用于将逆变换块213(即经重构残差块213)添加至预测块265，以在样本域中获取经重构块215，例如，将经重构残差块213的样本值与预测块265的样本值相加。
可选地，线缓冲器216的缓冲器单元216(或简称“缓冲器”216)可以用于缓冲或存储经重构块215和对应的样本值，用于例如帧内预测。在其它的实施例中，编码器可以用于使用存储在缓冲器单元216中的未经滤波的经重构块和/或对应的样本值来进行任何类别的估计和/或预测，例如帧内预测。
例如，编码器20的实施例可以经配置以使得缓冲器单元216不只用于存储用于帧内预测254的经重构块215，也用于环路滤波器单元220(在图2中未示出)，和/或，例如使得缓冲器单元216和经解码图片缓冲器单元230形成一个缓冲器。其它实施例可以用于 将经滤波块221和/或来自经解码图片缓冲器230的块或样本(图2中均未示出)用作帧内预测254的输入或基础。
环路滤波器单元220(或简称环路滤波器220)用于对经重构块215进行滤波以获取经滤波块221，从而顺利进行像素转变或提高视频质量。环路滤波器单元220旨在表示一个或多个环路滤波器，例如去块滤波器、样本自适应偏移(sample-adaptive offset，SAO)滤波器或其它滤波器，例如双边滤波器、自适应环路滤波器(adaptive loop filter，ALF)，或锐化或平滑滤波器，或协同滤波器。尽管环路滤波器单元220在图2中示出为环内滤波器，但在其它配置中，环路滤波器单元220可实施为环后滤波器。经滤波块221也可以称为经滤波的经重构块221。经解码图片缓冲器230可以在环路滤波器单元220对经重构编码块执行滤波操作之后存储经重构编码块。
编码器20(对应地，环路滤波器单元220)的实施例可以用于输出环路滤波器参数(例如，样本自适应偏移信息)，例如，直接输出或由熵编码单元270或任何其它熵编码单元熵编码后输出，例如使得解码器30可以接收并应用相同的环路滤波器参数用于解码。
经解码图片缓冲器(decoded picture buffer，DPB)230可以为存储参考图片数据供编码器20编码视频数据之用的参考图片存储器。DPB 230可由多种存储器设备中的任一个形成，例如动态随机存储器(dynamic random access memory，DRAM)(包含同步DRAM(synchronous DRAM，SDRAM)、磁阻式RAM(magnetoresistive RAM，MRAM)、电阻式RAM(resistive RAM，RRAM))或其它类型的存储器设备。可以由同一存储器设备或单独的存储器设备提供DPB 230和缓冲器216。在某一实例中，经解码图片缓冲器(decoded picture buffer，DPB)230用于存储经滤波块221。经解码图片缓冲器230可以进一步用于存储同一当前图片或例如先前经重构图片的不同图片的其它先前的经滤波块，例如先前经重构和经滤波块221，以及可以提供完整的先前经重构亦即经解码图片(和对应参考块和样本)和/或部分经重构当前图片(和对应参考块和样本)，例如用于帧间预测。在某一实例中，如果经重构块215无需环内滤波而得以重构，则经解码图片缓冲器(decoded picture buffer，DPB)230用于存储经重构块215。
预测处理单元260，也称为块预测处理单元260，用于接收或获取图像块203(当前图片201的当前图像块203)和经重构图片数据，例如来自缓冲器216的同一(当前)图片的参考样本和/或来自经解码图片缓冲器230的一个或多个先前经解码图片的参考图片数据231，以及用于处理这类数据进行预测，即提供可以为经帧间预测块245或经帧内预测块255的预测块265。
模式选择单元262可以用于选择预测模式(例如帧内或帧间预测模式)和/或对应的用作预测块265的预测块245或255，以计算残差块205和重构经重构块215。
模式选择单元262的实施例可以用于选择预测模式(例如，从预测处理单元260所支持的那些预测模式中选择)，所述预测模式提供最佳匹配或者说最小残差(最小残差意味着传输或存储中更好的压缩)，或提供最小信令开销(最小信令开销意味着传输或存储中更好的压缩)，或同时考虑或平衡以上两者。模式选择单元262可以用于基于码率失真优化(rate distortion optimization，RDO)确定预测模式，即选择提供最小码率失真优化的预测模式，或选择相关码率失真至少满足预测模式选择标准的预测模式。
下文将详细解释编码器20的实例(例如，通过预测处理单元260)执行的预测处理 和(例如，通过模式选择单元262)执行的模式选择。
如上文所述，编码器20用于从(预先确定的)预测模式集合中确定或选择最好或最优的预测模式。预测模式集合可以包括例如帧内预测模式和/或帧间预测模式。
帧内预测模式集合可以包括35种不同的帧内预测模式，例如，如DC(或均值)模式和平面模式的非方向性模式，或如H.265中定义的方向性模式，或者可以包括67种不同的帧内预测模式，例如，如DC(或均值)模式和平面模式的非方向性模式，或如正在发展中的H.266中定义的方向性模式。
在可能的实现中，帧间预测模式集合取决于可用参考图片(即，例如前述存储在DBP230中的至少部分经解码图片)和其它帧间预测参数，例如取决于是否使用整个参考图片或只使用参考图片的一部分，例如围绕当前图像块的区域的搜索窗区域，来搜索最佳匹配参考块，和/或例如取决于是否应用如半像素和/或四分之一像素内插的像素内插，帧间预测模式集合例如可包括先进运动矢量(advanced motion vector prediction，AMVP)模式和融合(merge)模式。具体实施中，帧间预测模式集合可包括本申请实施例改进的基于控制点的AMVP模式，以及，改进的基于控制点的merge模式。在一个实例中，帧内预测单元254可以用于执行下文描述的帧间预测技术的任意组合。
除了以上预测模式，本申请实施例也可以应用跳过模式和/或直接模式。
预测处理单元260可以进一步用于将图像块203分割成较小的块分区或子块，例如，通过迭代使用四叉树(quad-tree，QT)分割、二进制树(binary-tree，BT)分割或三叉树(triple-tree，TT)分割，或其任何组合，以及用于例如为块分区或子块中的每一个执行预测，其中模式选择包括选择分割的图像块203的树结构和选择应用于块分区或子块中的每一个的预测模式。
帧间预测单元244可以包含运动估计(motion estimation，ME)单元(图2中未示出)和运动补偿(motion compensation，MC)单元(图2中未示出)。运动估计单元用于接收或获取图片图像块203(当前图片201的当前图片图像块203)和经解码图片231，或至少一个或多个先前经重构块，例如，一个或多个其它/不同先前经解码图片231的经重构块，来进行运动估计。例如，视频序列可以包括当前图片和先前经解码图片31，或换句话说，当前图片和先前经解码图片31可以是形成视频序列的图片序列的一部分，或者形成该图片序列。
例如，编码器20可以用于从多个其它图片中的同一或不同图片的多个参考块中选择参考块，并向运动估计单元(图2中未示出)提供参考图片和/或提供参考块的位置(X、Y坐标)与当前图像块的位置之间的偏移(空间偏移)作为帧间预测参数。该偏移也称为运动向量(motion vector，MV)。
运动补偿单元用于获取帧间预测参数，并基于或使用帧间预测参数执行帧间预测来获取帧间预测块245。由运动补偿单元(图2中未示出)执行的运动补偿可以包含基于通过运动估计(可能执行对子像素精确度的内插)确定的运动/块向量取出或生成预测块。内插滤波可从已知像素样本产生额外像素样本，从而潜在地增加可用于编码图片块的候选预测块的数目。一旦接收到用于当前图片块的PU的运动向量，运动补偿单元246可以在一个参考图片列表中定位运动向量指向的预测块。运动补偿单元246还可以生成与块和视频条带相关联的语法元素，以供解码器30在解码视频条带的图片块时使用。
具体的，上述帧间预测单元244可向熵编码单元270传输语法元素，所述语法元素包括帧间预测参数(比如遍历多个帧间预测模式后选择用于当前图像块预测的帧间预测模式的指示信息)。可能应用场景中，如果帧间预测模式只有一种，那么也可以不在语法元素中携带帧间预测参数，此时解码端30可直接使用默认的预测模式进行解码。可以理解的，帧间预测单元244可以用于执行帧间预测技术的任意组合。
帧内预测单元254用于获取，例如接收同一图片的图片块203(当前图片块)和一个或多个先前经重构块，例如经重构相相邻块，以进行帧内估计。例如，编码器20可以用于从多个(预定)帧内预测模式中选择帧内预测模式。
编码器20的实施例可以用于基于优化标准选择帧内预测模式，例如基于最小残差(例如，提供最类似于当前图片块203的预测块255的帧内预测模式)或最小码率失真。
帧内预测单元254进一步用于基于如所选择的帧内预测模式的帧内预测参数确定帧内预测块255。在任何情况下，在选择用于块的帧内预测模式之后，帧内预测单元254还用于向熵编码单元270提供帧内预测参数，即提供指示所选择的用于块的帧内预测模式的信息。在一个实例中，帧内预测单元254可以用于执行帧内预测技术的任意组合。
具体的，上述帧内预测单元254可向熵编码单元270传输语法元素，所述语法元素包括帧内预测参数(比如遍历多个帧内预测模式后选择用于当前图像块预测的帧内预测模式的指示信息)。可能应用场景中，如果帧内预测模式只有一种，那么也可以不在语法元素中携带帧内预测参数，此时解码端30可直接使用默认的预测模式进行解码。
熵编码单元270用于将熵编码算法或方案(例如，可变长度编码(variable length coding，VLC)方案、上下文自适应VLC(context adaptive VLC，CAVLC)方案、算术编码方案、上下文自适应二进制算术编码(context adaptive binary arithmetic coding，CABAC)、基于语法的上下文自适应二进制算术编码(syntax-based context-adaptive binary arithmetic coding，SBAC)、概率区间分割熵(probability interval partitioning entropy，PIPE)编码或其它熵编码方法或技术)应用于经量化残差系数209、帧间预测参数、帧内预测参数和/或环路滤波器参数中的单个或所有上(或不应用)，以获取可以通过输出272以例如经编码比特流21的形式输出的经编码图片数据21。可以将经编码比特流传输到视频解码器30，或将其存档稍后由视频解码器30传输或检索。熵编码单元270还可用于熵编码正被编码的当前视频条带的其它语法元素。
视频编码器20的其它结构变型可用于编码视频流。例如，基于非变换的编码器20可以在没有针对某些块或帧的变换处理单元206的情况下直接量化残差信号。在另一实施方式中，编码器20可具有组合成单个单元的量化单元208和逆量化单元210。
具体的，在本申请实施例中，编码器20可用于实现后文实施例中描述的视频编码过程。
应当理解的是，本申请中的视频编码器可以只包括视频编码器20中的部分模块，例如，本申请中的视频编码器可以包括图像解码单元和划分单元。其中，图像解码单元可以由熵解码单元、预测单元、反变换单元和反量化单元中的一种或者多种单元组成。
另外，视频编码器20的其它的结构变化可用于编码视频流。例如，对于某些图像块或者图像帧，视频编码器20可以直接地量化残差信号而不需要经变换处理单元206处理，相应地也不需要经逆变换处理单元212处理；或者，对于某些图像块或者图像帧，视频编 码器20没有产生残差数据，相应地不需要经变换处理单元206、量化单元208、逆量化单元210和逆变换处理单元212处理；或者，视频编码器20可以将经重构图像块作为参考块直接地进行存储而不需要经滤波器220处理；或者，视频编码器20中量化单元208和逆量化单元210可以合并在一起。环路滤波器220是可选的，以及针对无损压缩编码的情况下，变换处理单元206、量化单元208、逆量化单元210和逆变换处理单元212是可选的。应当理解的是，根据不同的应用场景，帧间预测单元244和帧内预测单元254可以是被选择性的启用。
参见图3，图3示出用于实现本申请实施例的解码器30的实例的示意性/概念性框图。视频解码器30用于接收例如由编码器20编码的经编码图片数据(例如，经编码比特流)21，以获取经解码图片231。在解码过程期间，视频解码器30从视频编码器20接收视频数据，例如表示经编码视频条带的图片块的经编码视频比特流及相关联的语法元素。
在图3的实例中，解码器30包括熵解码单元304、逆量化单元310、逆变换处理单元312、重构单元314(例如求和器314)、缓冲器316、环路滤波器320、经解码图片缓冲器330以及预测处理单元360。预测处理单元360可以包含帧间预测单元344、帧内预测单元354和模式选择单元362。在一些实例中，视频解码器30可执行大体上与参照图2的视频编码器20描述的编码遍次互逆的解码遍次。
熵解码单元304用于对经编码图片数据21执行熵解码，以获取例如经量化系数309和/或经解码的编码参数(图3中未示出)，例如，帧间预测、帧内预测参数、环路滤波器参数和/或其它语法元素中(经解码)的任意一个或全部。熵解码单元304进一步用于将帧间预测参数、帧内预测参数和/或其它语法元素转发至预测处理单元360。视频解码器30可接收视频条带层级和/或视频块层级的语法元素。
逆量化单元310功能上可与逆量化单元110相同，逆变换处理单元312功能上可与逆变换处理单元212相同，重构单元314功能上可与重构单元214相同，缓冲器316功能上可与缓冲器216相同，环路滤波器320功能上可与环路滤波器220相同，经解码图片缓冲器330功能上可与经解码图片缓冲器230相同。
预测处理单元360可以包括帧间预测单元344和帧内预测单元354，其中帧间预测单元344功能上可以类似于帧间预测单元244，帧内预测单元354功能上可以类似于帧内预测单元254。预测处理单元360通常用于执行块预测和/或从经编码数据21获取预测块365，以及从例如熵解码单元304(显式地或隐式地)接收或获取预测相关参数和/或关于所选择的预测模式的信息。
当视频条带经编码为经帧内编码(I)条带时，预测处理单元360的帧内预测单元354用于基于信号表示的帧内预测模式及来自当前帧或图片的先前经解码块的数据来产生用于当前视频条带的图片块的预测块365。当视频帧经编码为经帧间编码(即B或P)条带时，预测处理单元360的帧间预测单元344(例如，运动补偿单元)用于基于运动向量及从熵解码单元304接收的其它语法元素生成用于当前视频条带的视频块的预测块365。对于帧间预测，可从一个参考图片列表内的一个参考图片中产生预测块。视频解码器30可基于存储于DPB 330中的参考图片，使用默认建构技术来建构参考帧列表：列表0和列表1。
预测处理单元360用于通过解析运动向量和其它语法元素，确定用于当前视频条带的 视频块的预测信息，并使用预测信息产生用于正经解码的当前视频块的预测块。在本申请的一实例中，预测处理单元360使用接收到的一些语法元素确定用于编码视频条带的视频块的预测模式(例如，帧内或帧间预测)、帧间预测条带类型(例如，B条带、P条带或GPB条带)、用于条带的参考图片列表中的一个或多个的建构信息、用于条带的每个经帧间编码视频块的运动向量、条带的每个经帧间编码视频块的帧间预测状态以及其它信息，以解码当前视频条带的视频块。在本申请的另一实例中，视频解码器30从比特流接收的语法元素包含接收自适应参数集(adaptive parameter set，APS)、序列参数集(sequence parameter set，SPS)、图片参数集(picture parameter set，PPS)或条带标头中的一个或多个中的语法元素。
逆量化单元310可用于逆量化(即，反量化)在比特流中提供且由熵解码单元304解码的经量化变换系数。逆量化过程可包含使用由视频编码器20针对视频条带中的每一视频块所计算的量化参数来确定应该应用的量化程度并同样确定应该应用的逆量化程度。
逆变换处理单元312用于将逆变换(例如，逆DCT、逆整数变换或概念上类似的逆变换过程)应用于变换系数，以便在像素域中产生残差块。
重构单元314(例如，求和器314)用于将逆变换块313(即经重构残差块313)添加到预测块365，以在样本域中获取经重构块315，例如通过将经重构残差块313的样本值与预测块365的样本值相加。
环路滤波器单元320(在编码循环期间或在编码循环之后)用于对经重构块315进行滤波以获取经滤波块321，从而顺利进行像素转变或提高视频质量。在一个实例中，环路滤波器单元320可以用于执行下文描述的滤波技术的任意组合。环路滤波器单元320旨在表示一个或多个环路滤波器，例如去块滤波器、样本自适应偏移(sample-adaptive offset，SAO)滤波器或其它滤波器，例如双边滤波器、自适应环路滤波器(adaptive loop filter，ALF)，或锐化或平滑滤波器，或协同滤波器。尽管环路滤波器单元320在图3中示出为环内滤波器，但在其它配置中，环路滤波器单元320可实施为环后滤波器。
随后将给定帧或图片中的经解码视频块321存储在存储用于后续运动补偿的参考图片的经解码图片缓冲器330中。
解码器30用于例如，藉由输出332输出经解码图片31，以向用户呈现或供用户查看。
视频解码器30的其它变型可用于对压缩的比特流进行解码。例如，解码器30可以在没有环路滤波器单元320的情况下生成输出视频流。例如，基于非变换的解码器30可以在没有针对某些块或帧的逆变换处理单元312的情况下直接逆量化残差信号。在另一实施方式中，视频解码器30可以具有组合成单个单元的逆量化单元310和逆变换处理单元312。
具体的，在本申请实施例中，解码器30用于实现后文实施例中描述的视频解码法。
应当理解的是，本申请中的视频编码器可以只包括视频编码器30中的部分模块，例如，本申请中的视频编码器可以包括划分单元和图像编码单元。其中，图像编码单元可以由预测单元、变换单元、量化单元和熵编码单元中的一种或者多种单元组成。
另外，视频解码器30的其它结构变化可用于解码经编码视频位流。例如，视频解码器30可以不经滤波器320处理而生成输出视频流；或者，对于某些图像块或者图像帧，视频解码器30的熵解码单元304没有解码出经量化的系数，相应地不需要经逆量化单元310和逆变换处理单元312处理。环路滤波器320是可选的；以及针对无损压缩的情况下， 逆量化单元310和逆变换处理单元312是可选的。应当理解的是，根据不同的应用场景，帧间预测单元和帧内预测单元可以是被选择性的启用。
应当理解的是，本申请的编码器20和解码器30中，针对某个环节的处理结果可以经过进一步处理后，输出到下一个环节，例如，在插值滤波、运动矢量推导或环路滤波等环节之后，对相应环节的处理结果进一步进行钳位(clip)或移位(shift)等操作。
例如，按照相邻仿射编码块(采用仿射运动模型进行预测的编码块可以称为仿射编码块)的运动矢量推导得到的当前图像块的控制点的运动矢量，或者推导得到的当前图像块的子块的运动矢量，可以做进一步的处理，本申请对此不做限定。例如，对运动矢量的取值范围进行约束，使其在一定的位宽内。假设允许的运动矢量的位宽为bitDepth，则运动矢量的范围为-2^(bitDepth-1)～2^(bitDepth-1)-1，其中“^”符号表示幂次方。如bitDepth为16，则取值范围为-32768～32767。如bitDepth为18，则取值范围为-131072～131071。
再如，还可以对运动矢量(例如一个8x8图像块内的四个4x4子块的运动矢量MV)的取值进行约束，使得所述四个4x4子块MV的整数部分之间的最大差值不超过N(例如，N可以取1)个像素。
参见图4，图4是根据一示例性实施例的包含图2的编码器20和/或图3的解码器30的视频译码***40的实例的说明图。视频译码***40可以实现本申请实施例的各种技术的组合。在所说明的实施方式中，视频译码***40可以包含成像设备41、编码器20、解码器30(和/或藉由处理单元46的逻辑电路47实施的视频编/解码器)、天线42、一个或多个处理器43、一个或多个存储器44和/或显示设备45。
如图4所示，成像设备41、天线42、处理单元46、逻辑电路47、编码器20、解码器30、处理器43、存储器44和/或显示设备45能够互相通信。如所论述，虽然用编码器20和解码器30绘示视频译码***40，但在不同实例中，视频译码***40可以只包含编码器20或只包含解码器30。
在一些实例中，天线42可以用于传输或接收视频数据的经编码比特流。另外，在一些实例中，显示设备45可以用于呈现视频数据。在一些实例中，逻辑电路47可以通过处理单元46实施。处理单元46可以包含专用集成电路(application-specific integrated circuit，ASIC)逻辑、图形处理器、通用处理器等。视频译码***40也可以包含可选的处理器43，该可选处理器43类似地可以包含专用集成电路(application-specific integrated circuit，ASIC)逻辑、图形处理器、通用处理器等。在一些实例中，逻辑电路47可以通过硬件实施，如视频编码专用硬件等，处理器43可以通过通用软件、操作***等实施。另外，存储器44可以是任何类型的存储器，例如易失性存储器(例如，静态随机存取存储器(static random access memory，SRAM)、动态随机存储器(dynamic random access memory，DRAM)等)或非易失性存储器(例如，闪存等)等。在非限制性实例中，存储器44可以由超速缓存内存实施。在一些实例中，逻辑电路47可以访问存储器44(例如用于实施图像缓冲器)。在其它实例中，逻辑电路47和/或处理单元46可以包含存储器(例如，缓存等)用于实施图像缓冲器等。
在一些实例中，通过逻辑电路实施的编码器20可以包含(例如，通过处理单元46或存储器44实施的)图像缓冲器和(例如，通过处理单元46实施的)图形处理单元。图形处理单元可以通信耦合至图像缓冲器。图形处理单元可以包含通过逻辑电路47实施的编 码器20，以实施参照图2和/或本文中所描述的任何其它编码器***或子***所论述的各种模块。逻辑电路可以用于执行本文所论述的各种操作。
在一些实例中，解码器30可以以类似方式通过逻辑电路47实施，以实施参照图3的解码器30和/或本文中所描述的任何其它解码器***或子***所论述的各种模块。在一些实例中，逻辑电路实施的解码器30可以包含(通过处理单元2820或存储器44实施的)图像缓冲器和(例如，通过处理单元46实施的)图形处理单元。图形处理单元可以通信耦合至图像缓冲器。图形处理单元可以包含通过逻辑电路47实施的解码器30，以实施参照图3和/或本文中所描述的任何其它解码器***或子***所论述的各种模块。
在一些实例中，天线42可以用于接收视频数据的经编码比特流。如所论述，经编码比特流可以包含本文所论述的与编码视频帧相关的数据、指示符、索引值、模式选择数据等，例如与编码分割相关的数据(例如，变换系数或经量化变换系数，(如所论述的)可选指示符，和/或定义编码分割的数据)。视频译码***40还可包含耦合至天线42并用于解码经编码比特流的解码器30。显示设备45用于呈现视频帧。
应理解，本申请实施例中对于参考编码器20所描述的实例，解码器30可以用于执行相反过程。关于信令语法元素，解码器30可以用于接收并解析这种语法元素，相应地解码相关视频数据。在一些例子中，编码器20可以将语法元素熵编码成经编码视频比特流。在此类实例中，解码器30可以解析这种语法元素，并相应地解码相关视频数据。
参见图5，图5是本申请实施例提供的视频译码设备400(例如视频编码设备400或视频解码设备400)的结构示意图。视频译码设备400适于实施本文所描述的实施例。在一个实施例中，视频译码设备400可以是视频解码器(例如图3的解码器30)或视频编码器(例如图2的编码器20)。在另一个实施例中，视频译码设备400可以是上述图3的解码器30或图2的编码器20中的一个或多个组件。
视频译码设备400包括：用于接收数据的入口端口410和接收单元(Rx)420，用于处理数据的处理器、逻辑单元或中央处理器(CPU)430，用于传输数据的发射器单元(Tx)440和出口端口450，以及，用于存储数据的存储器460。视频译码设备400还可以包括与入口端口410、接收器单元420、发射器单元440和出口端口450耦合的光电转换组件和电光(EO)组件，用于光信号或电信号的出口或入口。
处理器430通过硬件和软件实现。处理器430可以实现为一个或多个CPU芯片、核(例如，多核处理器)、FPGA、ASIC和DSP。处理器430与入口端口410、接收器单元420、发射器单元440、出口端口450和存储器460通信。处理器430包括译码模块470(例如编码模块470或解码模块470)。编码/解码模块470实现本文中所公开的实施例，以实现本申请实施例的编码方法/解码方法。例如，编码/解码模块470实现、处理或提供各种编码操作。因此，通过编码/解码模块470为视频译码设备400的功能提供了实质性的改进，并影响了视频译码设备400到不同状态的转换。或者，以存储在存储器460中并由处理器430执行的指令来实现编码/解码模块470。
存储器460包括一个或多个磁盘、磁带机和固态硬盘，可以用作溢出数据存储设备，用于在选择性地执行这些程序时存储程序，并存储在程序执行过程中读取的指令和数据。存储器460可以是易失性和/或非易失性的，可以是只读存储器(ROM)、随机存取存储器(RAM)、随机存取存储器(ternary content-addressable memory，TCAM)和/或静态随 机存取存储器(SRAM)。
参见图6，图6是根据一示例性实施例的可用作图1中的源设备12和目的地设备14中的任一个或两个的装置500的简化框图。装置500可以实现本申请实施例的编码方法或者解码方法。换言之，图6为本申请实施例的编码设备或解码设备(简称为译码设备500)的一种实现方式的示意性框图。其中，译码设备500可以包括处理器510、存储器530和总线***550。其中，处理器和存储器通过总线***相连，该存储器用于存储指令，该处理器用于执行该存储器存储的指令。译码设备的存储器存储程序代码，且处理器可以调用存储器中存储的程序代码执行本申请描述的各种视频编码或解码方法，尤其是各种新的图像块的划分方法。为避免重复，这里不再详细描述。
在本申请实施例中，该处理器510可以是中央处理单元(central processing unit，CPU)，该处理器510还可以是其他通用处理器、数字信号处理器(DSP)、专用集成电路(ASIC)、现成可编程门阵列(FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。
该存储器530可以包括只读存储器(ROM)设备或者随机存取存储器(RAM)设备。任何其他适宜类型的存储设备也可以用作存储器530。存储器530可以包括由处理器510使用总线550访问的代码和数据531。存储器530可以进一步包括操作***533和应用程序535，该应用程序535包括允许处理器510执行本申请描述的视频编码或解码方法的至少一个程序。例如，应用程序535可以包括应用1至N，其进一步包括执行在本申请描述的视频编码或解码方法的视频编码或解码应用(简称视频译码应用)。
该总线***550除包括数据总线之外，还可以包括电源总线、控制总线和状态信号总线等。但是为了清楚说明起见，在图中将各种总线都标为总线***550。
可选的，译码设备500还可以包括一个或多个输出设备，诸如显示器570。在一个示例中，显示器570可以是触感显示器，其将显示器与可操作地感测触摸输入的触感单元合并。显示器570可以经由总线550连接到处理器510。
为了更好地理解本申请实施例的编码方法和解码方法中的图像预测过程，下面先对帧间预测的一些相关概念和基本内容进行详细介绍。
帧间预测是指在已重建的图像中，为当前图像中的当前图像块寻找匹配的参考块，将该参考块中的像素点的像素值作为当前图像块中像素点的像素值的预测值，(此过程称为运动估计(Motion estimation，ME))。
运动估计是为当前图像块在参考图像中尝试多个参考块，然后采用率失真优化(rate-distortion optimization，RDO)或者其他方法从该多个参考块中最终确定出一个或者两个参考块(双向预测时需要两个参考块)，并利用该参考块对当前图像块进行帧间预测。
其中，当前图像块的运动信息包括了预测方向的指示信息(通常为前向预测、后向预测或者双向预测)，一个或两个指向参考块的运动矢量(motion vector，MV)，以及参考块所在图像的指示信息(通常记采用参考帧索引(reference index)来表示)。
前向预测是指当前图像块从前向参考图像集合中选择一个参考图像获取参考块。后向预测是指当前图像块从后向参考图像集合中选择一个参考图像获取参考块。双向预测是指从前向参考图像集合和后向参考图像集合中各选择一个参考图像来获取参考块。当使用双向预测方法时，当前编码块会存在两个参考块，每个参考块各自需要运动矢量和参考帧索 引进行指示，然后根据两个参考块内像素点的像素值确定当前图像块内像素点像素值的预测值。
在HEVC中，存在两种帧间预测模式，分别为AMVP模式和merge模式。
在AMVP模式中，是先遍历当前编码块空域或者时域相邻的已编码块(记为邻块)，根据各个邻块的运动信息构建候选运动矢量列表，然后通过率失真代价从候选运动信息列表中确定出最优的运动矢量，将率失真代价最小的候选运动信息作为当前编码块的运动矢量预测值(motion vector predictor，MVP)。
其中，邻块的位置及其遍历顺序都是预先定义好的。率失真代价可以根据公式(1)来计算获得，其中J为率失真代价(rate-distortion cost)，SAD为使用候选运动矢量预测值进行运动估计后得到的像素预测值与原始像素值之间的绝对误差和(sum of absolute differences，SAD)，R为码率，λ为拉格朗日乘子，编码端将选择的运动矢量预测值在候选运动矢量列表中的索引值和参考帧索引值传递到解码端。进一步地，编码端可以在MVP为中心的邻域内进行运动搜索获得当前编码块实际的运动矢量，然后将MVP与实际运动矢量之间的差值(motion vector difference)传递到解码端。
J＝SAD+λR               (1)
另外，根据运动模型的不同，AMVP模式可以分为基于平动模型的AMVP模式以及基于非平动模型的AMVP模式。
在merge模式中，是先通过当前编码单元空域或者时域相邻的已编码单元的运动信息，构建候选运动信息列表，然后通过率失真代价从候选运动信息列表中确定最优的运动信息作为当前编码单元的运动信息，最后再将最优的运动信息在候选运动信息列表中位置的索引值(记为merge index，下同)传递到解码端。
在merge模式中，当前编码单元空域和时域候选运动信息可以如图7所示，其中，空域候选运动信息来自空间相邻的5个块(A0,A1,B0,B1和B2)，若相邻块不可得或者为预测模式为帧内预测，则不将该相邻块加入候选运动信息列表。
当前编码单元的时域候选运动信息可以根据参考帧和当前帧的图序计数(picture order count，POC)对参考帧中对应位置块的MV进行缩放后获得。在获取参考帧对应位置块可以先判断参考帧中位置为T的块是否可得，若不可得则选择位置在C的块。
当采用平动模型进行预测时，编码单元内的所有像素都采用了相同的运动信息，然后根据运动信息进行运动补偿，得到编码单元的像素的预测值。但是在现实世界中，运动多种多样，存在很多非平动运动的物体，如旋转的物体，在不同方向旋转的过山车，投放的烟花和电影中的一些特技动作，特别是在用户生成内容(user generated content，UGC)场景中的运动物体，对它们的编码，如果采用当前编码标准中的基于平动运动模型的块运动补偿技术，编码效率会受到很大的影响，因此，为了提高编码效果，提出了一种基于非平动运动模型的预测。
非平动运动模型预测指在编解码端使用相同的运动模型推导出当前编码块内每一个子运动补偿单元的运动信息，然后根据子运动补偿单元的运动信息进行运动补偿，得到每一个子块的预测子块，从而提高预测效率。常用的非平动运动模型有4参数仿射运动模型或者6参数仿射运动模型。
一般来说，在同一地理位置附近，往往存在相同或相近的地形地貌特征。因此，对于 定位图层来说，定位图层中在同一地理位置附近的多幅网格图片之间往往存在着一定的相关性(例如相似的纹理)。如果在对定位图层进行编码时，将定位图层中的同一地理位置附近的多福网格图片组成一个图像序列，然后对该图像序列进行帧间预测编码，能够使得根据帧间预测过程得到的网格图片的残差图片的数据量较小，进而使得最终编码生成的码流的数据量也比较小，从而能够减少编码生成的码流占用的存储开销。
下面结合附图对本申请实施例的图像编码方法和图像解码方法进行详细的描述。
图8是本申请实施例的图像编码方法的过程的示意图。
图8所示的方法可以由编码装置或者编码器执行。图8示出了本申请实施例的图像编码方法的主要过程，在图8所示的方法中，可以将地理位置相近的图像组成图像序列(也可以将图像内容相似的图像组成图像序列)，然后再采用基于帧间预测的编码方式进行编码，得到码流。这里的基于帧间预测的编码是指在对图像进行预测时采用帧间预测方式的编码方法。
由于地理位置相邻的图像的图像内容的相似度较高，因此，通过对图像序列中的图像进行帧间预测，得到预测图像，并根据得到预测图像获取图像的残差图像。使得最终得到的残差图像的数据量较小，使得最终编码生成的码流的数据量也较小，从而能够减少编码得到的码流占用的存储空间。
为了进一步的减少编码得到的码流占用的存储空间，还可以在对图像序列中的图像进行编码之前或者对图像序列中的图像的编码过程中进行异或处理或者取反处理，然后再对图像序列中的图像进行编码。这样能够在图像序列中的图像的像素值包含连续的占位符的情况下，降低图像的数据量，进而使得编码生成的码流占用更少的存储空间。
具体地，可以在得到图像之后就对图像的像素值进行异或处理或者取反处理，也可以在得到图片之后先将地理位置相邻的图像组成图像序列，然后再对图像序列中的图片进行异或处理或者取反处理。
如图9所示，在获取图像之后，先对该图像进行异或处理或者取反处理，接下来，从处理后的图像中选择地理位置相近的图像组成图像序列，然后再基于帧间预测的编码对该图像序列进行编码，得到码流。
如图10所示，在获取图像之后，先将地理位置相近的图像组成图像序列，然后再对图像序列中的图像进行异或处理或者取反处理，接下来再基于帧间预测的编码方式对处理后的图像序列进行编码得到码流。
下面先结合图11对本申请实施例的图像解码方法的进行详细的介绍。
图11是本申请实施例的图像解码方法的示意性流程图。图11所示的方法可以由解码装置或者解码器执行。图11所示的方法包括步骤1001至1004，下面对步骤1001至1004进行详细的介绍。
1001、获取码流。
步骤1001中获取的码流可以是下文中图14所示的编码方法中编码得到的码流。
1002、根据码流，获取图像序列中的网格图像的残差图像。
步骤1002中可以通过解析码流的方式获取当前图像块的残差块，具体的解析过程可以参见图3所示的解码的相关过程。
上述图像序列包括多个网格图像，该多个网格图像对应的地理位置相近或者该多个网 格图像的图像内容相近。具体地，上述多个网格图像对应的地理位置相近或者该多个网格图像的图像内容相近可以是指上述多个网格图像满足第一条件。
上述第一条件有多种不同的具体表现形式。
可选地，上述第一条件可以为上述图像序列中的多个网格图像中的至少两个网格图像对应的地理位置之间的间距小于预设距离。
上述预设距离也可以成为距离阈值，该预设距离的大小可以根据实际需要来灵活设置。例如，上述预设距离可以设置为3m(3米)，当两个网格图像的对应的地理位置之间的间距小于3m时，这两个网格图像满足第一条件。这里的3m仅仅为示例，预设距离还可以设置成5m和6m等等，总之可以根据需要设置任何合适大小的预设距离。
另外，上述第一条件还可以是多个网格图像中的至少两个网格图像对应的地理位置之间的间距小于或者等于预设距离。
由于地理位置相近的图像的相似度一般比较高，因此，当图像序列中包含对应地理位置相邻的至少两个网格图像时，通过对该图像序列进行帧间预测，能够使得后续得到的残差图像的数据量较小。
可选地，上述第一条件可以为上述图像序列中的至少两个网格图像的图像内容的相似度大于或者等于预设相似度。
上述预设相似度还可以称为相似度阈值，该预设相似度的大小可以根据实际需要来灵活设置。例如，上述预设相似度可以设置为50％，当两个网格图像的图像内容的相似度大于或者等于50％时，这两个网格图像满足第一条件。这里的50％仅仅为示例，预设相似度还可以设置成55％，60％以及65％等等，总之可以根据需要设置任何合适大小的预设相似度。
另外，上述第一条件还可以是多个网格图像中的至少两个网格图像的图像内容的相似度大于预设相似度。
当图像序列中包含图像内容相近的至少两个网格图像时，通过对该图像序列进行帧间预测，能够使得后续得到的残差图像的数据量较小。
可选地，上述第一条件可以为多个网格图像中的至少两个网格图像的图像内容对应于同一地理区域。
由于同一地理区域的图像的相似度一般会比较高，因此，当图像序列中包含位于同一地理区域的至少两个网格图像时，通过对该图像序列进行帧间预测，能够使得后续得到的残差图像的数据量较小。
上述地理区域的大小可以是预设大小，该地理区域的大小可以根据实际需要来设定。例如，上述地理区域的大小可以是2m×2m的区域。应理解，这里的2m×2m的区域的地理区域大小仅仅为示例，地理区域的大小还可能设置为1m×1m的区域，3m×32m的区域等等，总之可以根据需要设置任何合适大小的地理区域。
再如，上述地理区域的大小为2m×2m的区域，当两个网格图像均位于2m×2m的区域时，这两个网格图像满足第一条件。
进一步的，上述多个网格图像中的至少两个网格图像可以是彼此之间为相邻帧的网格图像。
也就是说，上述满足第一条件的至少两个网格图像彼此之间为相邻帧。例如，上述图 像序列中的网格图像1、网格图像2和网格图像3满足上述第一条件。那么，网格图像1，网格图像2和网格图像3可以分别是图像序列中的第i帧，第i+1帧和第i+2帧。其中，i为正整数。
1003、对图像序列中的网格图像进行帧间预测，得到图像序列中的网格图像的预测图像。
步骤1003中通过帧间预测，进而获取图像序列中的网格图像的预测图像的过程可以参见图3所示的解码的相关过程。
1004、根据图像序列中的网格图像的残差图像和图像序列中的网格图像的预测图像，得到图像序列中的网格图像。
在步骤1004中，可以通过将图像序列中的网格图像的残差图像和图像序列中的网格图像的预测图像进行叠加，来得到图像序列中的网格图像。应理解，在图11所示的方法中，网格图像的预测图像可以是由网格图像中的各个图像块的预测块组成，网格图像的残差图像可以由网格图像中的各个图像块的残差块组成。因此，在图11的方法中，在解析码流最终得到图像序列中的网格图像的过程中，可以是以图像块为基本单位进行解码操作的，具体地，在步骤1002中，可以根据码流获取到图像序列中的网格图像的图像块的残差块，然后再步骤1003中对该图像块进行帧间预测，得到该图像块的预测块，接下来，在步骤1004中根据残差块和预测块，最终得到相应的图像块。在得到各个图像块之后，可以将图像块拼接成网格图像，这样，在解码端就相当于是根据网格图像的残差图像和网格图像的预测图像来得到网格图像了。
上述步骤1004的具体实现可以参见图3所示的解码的相关过程。
本申请中，由于图像序列中包含地理位置相近或者图像内容相近的网格图像，因此，在对该图像序列进行帧间预测时，能够使得得到的残差图像的数据量较小，进而使得最终图像序列对应的码流占用的存储空间较小，便于存储或者传输。
在本申请实施例中，编码端在对图像序列中的网格图像进行编码之前或者编码的过程中，还可以对图像序列中的网格图像的像素值进行取反处理或者异或处理，以进一步降低编码生成的码流占用的存储空间，相应的，解码端在解码过程中或者解码之后也可以对相应的图像进行取反处理或者异或处理，从而得到最终的图像。下面对这种处理方式进行详细的介绍。
具体地，在图11所示的方法中，可以在解码得到图像序列的网格图像之后，再对图像序列中的网格图像进行处理，以得到最终的网格图像。
如图12所示，在通过解码得到图像序列的网格图像之后，图11所示的方法还包括：
1005、对图像序列中的网格图像进行处理，得到处理后的网格图像。
其中，上述图像序列中的网格图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数。
上述步骤1005中得到的处理后的网格图像和网格图像可以满足第一关系。
第一关系：处理后的网格图像的像素值的取值和网格图像的像素值的取值相反。
具体地，在第一关系下，图像序列中的网格图像的像素值的N个比特中第i个比特的取值，与处理后的图像序列中的网格图像的像素值的N个比特中的第i个比特的取值相反，图像序列中的网格图像的像素值的N个比特与处理后的图像序列中的网格图像的像素值 的N个比特所处的位置相同；图像序列中的网格图像的像素值的N个比特位于图像序列中的网格图像的像素值的第一比特之后并且与第一比特相邻，第一比特是图像序列中的网格图像的像素值中取值为1并且位数最高的比特位，i和N均为正整数，i≤N，N＜M。
在本申请中，编码端通过对网格图像的像素值进行取反处理，能够在网格图像的像素值包含连续的占位符的情况下，降低网格图像的数据量，进而使得编码生成的码流占用更少的存储空间，而解码端通过对解码得到的网格图像进行(取反)处理，从而能够将编码端处理(取反处理)过的网格图像进行还原，进而获得最终的网格图像。
在解码得到图像序列的网格图像之后，除了可以对图像序列的网格图像的像素值进行取反处理之外，还可以对图像序列的网格图像的像素值进行异或处理。
因此，上述步骤1005中得到的处理后的网格图像和网格图像除了满足第一关系之外，还可以满足第二关系。
第二关系：处理后的网格图像的像素值是像素值的异或结果。
具体地，在第二关系下，处理后的图像序列中的网格图像的N个比特中的第1个比特的取值与图像序列中的网格图像的N个比特中的第1个比特的取值相反，处理后的图像序列中的网格图像的N个比特中的第i+1个比特的取值是图像序列中的网格图像的N个比特中的第i+1个比特的取值与处理后的图像序列中的网格图像的N个比特中的第i个比特进行异或处理的结果；图像序列中的网格图像的像素值的N个比特位于图像序列中的网格图像的像素值的第一比特之后并且与第一比特相邻，第一比特是图像序列中的网格图像的像素值中取值为1并且位数最高的比特位，或者，图像序列中的网格图像的像素值的N个比特位于图像序列中的网格图像的像素值的最高比特位之后并且与图像序列中的网格图像的像素值的最高比特位相邻。
另外，在第二关系下，图像序列中的网格图像的像素值的N个比特与处理后的图像序列中的网格图像的像素值的N个比特所处的位置相同，第i个比特的位数高于第i+1个比特的位数，i和N均为正整数，i≤N，N＜M。
本申请中，编码端通过对网格图像的像素值进行异或处理，能够在网格图像的像素值包含连续的占位符的情况下，降低网格图像的数据量，进而使得编码生成的码流占用更少的存储空间，而解码端通过对解码得到的网格图像进行(异或)处理，从而能够将编码端处理(异或处理)过的网格图像进行还原，进而获得最终的网格图像。
在图11所示的方法中，除了可以在解码得到图像序列中的网格图像之后再对该图像序列中的网格图像进行处理，也可以在解码得到网格图像中的网格图像的残差图像之后就对该残差图像进行处理，下面进行详细介绍。
如图13所示，在步骤1002之后，可以执行步骤步骤1003a。
1003a、对残差图像进行处理，得到处理后的残差图像。
在步骤1003a之后再执行步骤1004时，步骤1004是根据处理后的残差图像和图像序列中的网格图像的预测图像，来得到图像序列中的网格图像。
其中，上述残差图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数。
上述步骤1003a得到的处理后的残差图像和残差图像可以满足第三关系。
第三关系：处理后的残差图像的像素值的取值和残差图像的像素值的取值相反。
具体地，在第三关系下，其中，残差图像的像素值的N个比特中的第i个比特的取值，与处理后的残差图像的像素值的N个比特中的第i个比特的取值相反，残差图像的像素值的N个比特与处理后的残差图像的像素值的N个比特所处的位置相同。残差图像的像素值的N个比特位于残差图像的像素值的第一比特之后并且与第一比特相邻，第一比特是残差图像的像素值中取值为1并且位数最高的比特位，i和N均为正整数，i≤N，N＜M。
本申请中，编码端通过对残差图像的像素值进行取反处理，能够在残差图像的像素值包含连续的占位符的情况下，降低残差图像的数据量，进而使得编码生成的码流占用更少的存储空间，而解码端通过对解码得到的残差图像进行(取反)处理，从而能够将编码端处理(取反处理)过的残差图像进行还原，进而根据该处理后的残差图像得到最终的图像块。
在上述步骤1003a中除了对残差图像的像素值进行取反处理之外，还可以对残差图像的像素值进行异或处理。
因此，上述步骤1003a中得到的处理后的残差图像和残差图像除了满足第三关系之外，还可以满足第四关系。
第四关系：处理后的残差图像的像素值是像素值的异或结果。
具体地，在第四关系下，处理后的残差图像的N个比特中的第1个比特的取值与残差图像的N个比特中的第1个比特的取值相反，处理后的残差图像的N个比特中的第i+1个比特的取值是残差图像的N个比特中的第i+1个比特的取值与处理后的残差图像的N个比特中的第i个比特进行异或处理的结果。残差图像的像素值的N个比特位于残差图像的像素值的第一比特之后并且与第一比特相邻，第一比特是残差图像的像素值中取值为1并且位数最高的比特位，或者，残差图像的像素值的N个比特位于残差图像的像素值的最高比特位之后并且与残差图像的像素值的最高比特位相邻。
另外，在第四关系下，残差图像的像素值的N个比特与处理后的残差图像的像素值的N个比特所处的位置相同，第i个比特的位数高于第i+1个比特的位数，i和N均为正整数，i≤N，N＜M；
本申请中，编码端通过对残差图像的像素值进行异或处理，能够在残差图像的像素值包含连续的占位符的情况下，降低残差图像的数据量，进而使得编码生成的码流占用更少的存储空间，而解码端通过对解码得到的残差图像进行(异或)处理，从而能够将编码端处理(异或处理)过的残差图像进行还原，进而根据该处理后的残差图像得到最终的图像块。
在本申请中，编码端在对图像序列中的网格图像进行编码时既可以采用无损编码也可以采用有损编码，相应的，解码端要采用与编码端匹配的方式进行解码。
可选地，作为一个实施例，上述步骤1002中根据码流，获取图像序列中的网格图像的残差图像，包括：对码流进行反变换、反量化和熵解码处理，得到残差图像。
上述解码处理对应于图像的有损编码，这种方式能够使得编码得到的码流尽可能的占用较小的存储空间。
可选地，作为一个实施例，上述步骤1002中根据码流，获取图像序列中的网格图像的残差图像，包括：对码流进行熵解码处理，得到残差图像。
上述仅进行熵解码处理的解码方式对应于无损编码，这种编码方式能够尽可能的避免 图像失真，保证图像最终的显示效果。
可选地，作为一个实施例，上述码流是对定位图层进行编码得到的。
可选地，作为一个实施例，上述定位图层的像素值包含栅格化后的高程数据。
上述定位图层的像素值包含M个比特，每个比特表示每个栅格的占有位。由于定位图层的像素值中包含栅格化后的高程数据，而高程数据中高位出现字符“11”的概率比较高，因此，通过对包含高程数据的定位图层的像素值进行处理，能够降低定位图层的像素值的数据量，进而减少最终得到的码流占用的存储空间。
可选地，在上述第一关系至第四关系中，M的取值可以为8、10和12中的任意一个。
上文结合图11至图13对本申请实施例的图像解码方法进行了详细描述，下面结合图14从编码端的角度对本申请实施例的图像编码方法进行详细的描述。
图14是本申请实施例的图像编码方法的示意性流程图。图14所示的方法可以由编码装置或者编码器执行。图14所示的方法包括步骤2001至2003，下面对步骤2001至2003进行详细的介绍。
2001、获取图像序列。
2002、对图像序列中的网格图像进行帧间预测，得到残差图像。
可选地，上述对图像序列中的网格图像进行帧间预测，得到残差图像，包括：对图像序列中的网格图像进行帧间预测，得到预测图像；根据该图像序列中的网格图像和预测图像，得到该网格图像的残差图像。
在得到预测图像之后，可以是将网格图像与该网格图像的残差图像进行做差，得到该网格图像的残差图像。
另外，上述图像序列包括多个网格图像，该多个网格图像对应的地理位置相近或者该多个网格图像的图像内容相近。具体地，上述多个网格图像对应的地理位置相近或者该多个网格图像的图像内容相近可以是指上述多个网格图像满足第一条件。
上述第一条件有多种不同的具体表现形式。
可选地，上述第一条件可以为上述图像序列中的多个网格图像中的至少两个网格图像对应的地理位置之间的间距小于预设距离。
上述预设距离也可以成为距离阈值，该预设距离的大小可以根据实际需要来灵活设置。例如，上述预设距离可以设置为3m，当两个网格图像的对应的地理位置之间的间距小于3m时，这两个网格图像满足第一条件。这里的3m仅仅为示例，预设距离还可以设置成5m和6m等等，总之可以根据需要设置任何合适大小的预设距离。
另外，上述第一条件还可以是多个网格图像中的至少两个网格图像对应的地理位置之间的间距小于或者等于预设距离。
由于地理位置相近的图像的相似度一般比较高，因此，当图像序列中包含对应地理位置相邻的至少两个网格图像时，通过对该图像序列进行帧间预测，能够使得后续得到的残差图像的数据量较小。
可选地，上述第一条件可以为上述图像序列中的至少两个网格图像的图像内容的相似度大于或者等于预设相似度。
上述预设相似度还可以称为相似度阈值，该预设相似度的大小可以根据实际需要来灵活设置。例如，上述预设相似度可以设置为50％，当两个网格图像的图像内容的相似度大 于或者等于50％时，这两个网格图像满足第一条件。这里的50％仅仅为示例，预设相似度还可以设置成55％，60％以及65％等等，总之可以根据需要设置任何合适大小的预设相似度。
另外，上述第一条件还可以是多个网格图像中的至少两个网格图像的图像内容的相似度大于预设相似度。
当图像序列中包含图像内容相近的至少两个网格图像时，通过对该图像序列进行帧间预测，能够使得后续得到的残差图像的数据量较小。
可选地，上述第一条件可以为多个网格图像中的至少两个网格图像的图像内容对应于同一地理区域。
由于同一地理区域的图像的相似度一般会比较高，因此，当图像序列中包含位于同一地理区域的至少两个网格图像时，通过对该图像序列进行帧间预测，能够使得后续得到的残差图像的数据量较小。
上述地理区域的大小可以是预设大小，该地理区域的大小可以根据实际需要来设定。例如，上述地理区域的大小可以是2m×2m的区域。应理解，这里的2m×2m的区域的地理区域大小仅仅为示例，地理区域的大小还可能设置为1m×1m的区域，3m×32m的区域等等，总之可以根据需要设置任何合适大小的地理区域。
再如，上述地理区域的大小为2m×2m的区域，当两个网格图像均位于2m×2m的区域时，这两个网格图像满足第一条件。
进一步的，上述至少两个网格图像可以是彼此之间为相邻帧的网格图像。
也就是说，上述满足第一条件的至少两个网格图像彼此之间为相邻帧。例如，上述图像序列中的网格图像1、网格图像2和网格图像3满足上述第一条件。那么，网格图像1，网格图像2和网格图像3可以分别是图像序列中的第i帧，第i+1帧和第i+2帧。其中，i为正整数。
2003、对残差图像进行编码，得到编码码流。
本申请中，由于图像序列中包含地理位置相近或者图像内容相近的网格图像，因此，在对该图像序列进行帧间预测时，能够使得得到的残差图像的数据量较小，进而使得最终对图像序列进行编码得到的码流占用的存储空间较小，便于存储或者传输。
在图14所示的方法中，上述网格图像的预测图像可以是由网格图像中的各个图像块的预测块组成，网格图像的残差图像可以由网格图像中的各个图像块的残差块组成。在编码端进行编码时，可以将残差图像划分成图像块，然后获取每个图像块的预测块，并根据每个图像块和每个图像块的残差块，得到每个图像块的残差块，进而得到网格图像的残差图像。
在本申请实施例中，编码端在对图像序列中的网格图像进行编码之前或者编码的过程中，还可以对图像序列中的网格图像的像素值进行取反处理或者异或处理，以进一步降低编码生成的码流占用的存储空间。
具体地，在图14所示的方法中，可以在对图像序列中的网格图像进行编码之前，先对该图像序列中的网格图像进行处理，然后再对处理后的网格图像进行编码。
如图15所示，在执行步骤2002之前，先执行步骤2002a。
2002a、对图像序列中的网格图像进行处理，得到处理后的网格图像。
在步骤2002a之后，再执行步骤2002时，步骤2002就是根据处理后的网格图像进行帧间预测，以得到残差图像了。
其中，上述图像序列中的网格图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数。
上述步骤2002a得到的处理后的网格图像和网格图像可以满足第五关系。
第五关系：处理后的网格图像的像素值的取值和网格图像的像素值的取值相反。
具体地，在第五关系下，图像序列中的网格图像的像素值的N个比特中第i个比特的取值，与处理后的图像序列中的网格图像的像素值的N个比特中的第i个比特的取值相反，图像序列中的网格图像的像素值的N个比特与处理后的图像序列中的网格图像的像素值的N个比特所处的位置相同。
另外，在第五关系下，图像序列中的网格图像的像素值的N个比特位于图像序列中的网格图像的像素值的第一比特之后并且与第一比特相邻，第一比特是图像序列中的网格图像的像素值中取值为1并且位数最高的比特位，i和N均为正整数，i≤N，N＜M。
本申请中，编码端通过对网格图像的像素值进行取反处理，能够在网格图像的像素值包含连续的占位符的情况下，降低网格图像的数据量，进而使得编码生成的码流占用更少的存储空间。
进一步的，上述N在不同的取值下，对应的编码性能也不相同，当N取某个特定的数值时，对应的编码性能最优，减少的比特是最多的。
如图16，当网格图像的像素值共对应8个比特时，对网格图像的像素值中的N个比特进行取反处理时，能够减小一定的比特数，当N＝3时，比特数减小的程度最大，相应的编码性能也是最优的。
在实际编码过程中，可以根据测试的结果或者经验来设置N的数值，例如，当网格图像的像素值共对应8个比特位时，可以选择N＝3或者N＝4，这样能够取得较好的编码性能，可以尽可能的降低网格图像的数据量。
在本申请中，除了可以对图像序列中的网格图像的像素值进行取反处理之后，还可以对图像序列中的网格图像的像素值进行异或处理。
因此，上述步骤2002a得到的处理后的网格图像和网格图像除了满足第五关系之外，还可以满足第六关系。
第六关系：处理后的网格图像的像素值是像素值的异或结果。
具体地，在第六关系下，处理后的图像序列中的网格图像的N个比特中的第1个比特的取值与图像序列中的网格图像的N个比特中的第1个比特的取值相反，处理后的图像序列中的网格图像的N个比特中的第i+1个比特的取值是图像序列中的网格图像的N个比特中的第i+1个比特的取值与处理后的图像序列中的网格图像的N个比特中的第i个比特进行异或处理的结果。
另外，在第六关系下，图像序列中的网格图像的像素值的N个比特位于图像序列中的网格图像的像素值的第一比特之后并且与第一比特相邻，第一比特是图像序列中的网格图像的像素值中取值为1并且位数最高的比特位，或者，图像序列中的网格图像的像素值的N个比特位于图像序列中的网格图像的像素值的最高比特位之后并且与图像序列中的网格图像的像素值的最高比特位相邻。图像序列中的网格图像的像素值的N个比特与处理后 的图像序列中的网格图像的像素值的N个比特所处的位置相同，第i个比特的位数高于第i+1个比特的位数，i和N均为正整数，i≤N，N＜M。
本申请中，编码端通过对网格图像的像素值进行异或处理，能够在网格图像的像素值包含连续的占位符的情况下，降低网格图像的数据量，进而使得编码生成的码流占用更少的存储空间。
进一步的，上述N在不同的取值下，对应的编码性能也不相同，当N的取值越大时，对应的编码性能越好，减少的比特也越多。
如图17，当网格图像的像素值共对应8个比特时，对网格图像的像素值中的N个比特进行异或处理时，能够减小一定的比特数，当N＝6时，比特数减小的程度最大，相应的编码性能也是最优的。
在实际编码过程中，可以根据测试的结果或者经验来设置N的数值，例如，当网格图像的像素值共对应8个比特位时，可以为N设置一个较大的数值，例如，将N设置为5或者6，这样能够取得较好的编码性能，可以尽可能的降低网格图像的数据量。
在本申请的图像编码方法中，除了可以在对图像序列中的网格图像进行编码之前对图像序列中的网格图像进行取反处理或者异或处理之外，还可以在得到图像序列的网格图像的残差图像之后，对残差图像进行取反处理或者异或处理。下面进行详细介绍。
如图18所示，步骤2003具体可以包括步骤2003a和步骤2003b。
2003a、对残差图像进行处理，得到处理后的残差图像。
2003b、对处理后的残差图像进行编码，得到编码码流。
其中，上述残差图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数。
上述步骤1003a得到的处理后的残差图像和残差图像可以满足第七关系。
第七关系：处理后的残差图像的像素值的取值和残差图像的像素值的取值相反。
具体地，在第七关系下，残差图像的像素值的N个比特中的第i个比特的取值，与处理后的残差图像的像素值的N个比特中的第i个比特的取值相反，残差图像的像素值的N个比特与处理后的残差图像的像素值的N个比特所处的位置相同。残差图像的像素值的N个比特位于残差图像的像素值的第一比特之后并且与第一比特相邻，第一比特是残差图像的像素值中取值为1并且位数最高的比特位，i和N均为正整数，i≤N，N＜M。
本申请实施例中，编码端通过对残差图像的像素值进行异或处理，能够在残差图像的像素值包含连续的占位符的情况下，降低残差图像的数据量，进而使得编码生成的码流占用更少的存储空间。
在上述步骤2003a中除了对残差图像的像素值进行取反处理之外，还可以对残差图像的像素值进行异或处理。
因此，上述步骤2003a中得到的处理后的残差图像和残差图像除了满足第七关系之外，还可以满足第八关系。
第八关系：处理后的残差图像的像素值是像素值的异或结果。
具体地，在第八关系下，残差图像的像素值的N个比特中第i个比特的取值，与处理后的残差图像的像素值的N个比特中的第i个比特的取值相反，处理后的残差图像的N个比特中的第i+1个比特的取值是残差图像的N个比特中的第i+1个比特的取值与处理后的 残差图像的N个比特中的第i个比特进行异或处理的结果。
另外，在第八关系下，残差图像的像素值的N个比特位于残差图像的像素值的第一比特之后并且与第一比特相邻，第一比特是残差图像的像素值中取值为1并且位数最高的比特位，或者，残差图像的像素值的N个比特位于残差图像的像素值的最高比特位之后并且与残差图像的像素值的最高比特位相邻。残差图像的像素值的N个比特与处理后的残差图像的像素值的N个比特所处的位置相同，第i个比特的位数高于第i+1个比特的位数，i和N均为正整数，i≤N，N＜M。
本申请实施例中，编码端通过对残差图像的像素值进行异或处理，能够在残差图像的像素值包含连续的占位符的情况下，降低残差图像的数据量，进而使得编码生成的码流占用更少的存储空间。
在本申请实施例的图像编码方法中，既可以采用无损编码，也可以采用有损编码。
可选地，作为一个实施例，上述步骤2003中对残差图像进行编码，得到编码码流，包括：对残差图像进行变换、量化和熵编码处理，得到编码码流。
通过进行有损编码，能够使得编码得到的码流尽可能的占用较小的存储空间。
可选地，作为一个实施例，上述步骤2003中对残差图像进行编码，得到编码码流，包括：对残差图像进行熵编码处理，得到编码码流。
通过无损编码，能够尽可能的避免图像失真，保证图像最终的显示效果。
可选地，作为一个实施例，上述图像序列中的网格图片来自定位图层。
可选地，作为一个实施例，上述定位图层的像素值包含栅格化后的高程数据。
上述定位图层的像素值包含M个比特，每个比特表示每个栅格的占有位。由于定位图层的像素值中包含栅格化后的高程数据，而高程数据中高位出现字符“11”的概率比较高，因此，通过对包含高程数据的定位图层的像素值进行处理，能够降低定位图层的像素值的数据量，进而减少最终得到的码流占用的存储空间。
可选地，在上述第五关系至第八关系中，M的取值可以为8、10和12中的任意一个。
在本申请实施例中，图像序列中的网格图像可以包含I帧图像和P帧图像。如图19所示，该图像序列中包含1个I帧和3个P帧，对于其中的P帧，可以采用帧间预测的方式进行预测。应理解，图19所示的图像序列中仅为示意，本申请实施例中对图像序列包含的网格图像的数量不做限制。
另外，本申请实施例中的图像序列还可以包括B帧。
在本申请实施例中，图像序列中的网格图像可以来自定位图层，该定位图层可以是3D点云数据映射得到的2D平面数据。
一般来说，3D点云数据由于数据量巨大，经常需要先将3D点云数据转化为2D平面数据作为定位图层。如图20所示，3D点云数据包含三维坐标(x，y，z)和反射率(r)等数据，在转化为2D平面数据时，可以将3D点云数据的(x，y)直接作为2D平面数据的(x，y)坐标(x和y相当于像素在图片中的位置)，将3D点云数据中的高度z映射到2D平面数据的R通道上，将反射率r映射到G通道上，这样就实现了将3D点云数据到2D平面数据的转换。
下面结合具体的测试结果对本申请实施例的图像编码方法的效果进行说明。
如表1所示，序列1和序列2分别为两个图像序列，这两个图像序列均包含的是便携 式网络图形(portable network graphics，PNG)格式的图片，其中，序列1包含4个网格图片(1a.png、1b.png、1c.png、1d.png)，序列2也包括4个网格图片(2a.png、2b.png、2c.png、2d.png)。
在对序列1和序列2进行编码时，与采用高效视频编码-屏幕内容编码(high efficiency video coding-screen content coding，HEVC-SCC)单独压缩(传统方案)相比，采用HEVC-SCC组合压缩(相当于本申请实施例的编码方法)对图像序列进行编码时，得到的码流的数据量更小一些。
例如，对于序列1，HEVC-SCC组合压缩后的数据量相对于原图像序列的数据量减小了9.9％，HEVC-SCC单独压缩后的数据量相对于原图像序列的数据量减小了9.5％。而采用了HEVC-SCC组合压缩+数据预处理的方式(相当于本申请实施例的图像编码方法中对网格图像进行了异或处理或者取反处理)得到的码流相对于单独采用HEVC-SCC组合压缩的方式相比，得到的码流的数据量更小。例如，对于序列1来说，单独采用HEVC-SCC组合压缩方式得到的码流的数据量相对于原图像序列的数据量减小了9.9％，而采用HEVC-SCC组合压缩+数据预处理的方式得到的码流的数据量相对于原图像序列的数据量减小了10.3％。
表1
Figure PCTCN2020101886-appb-000001
上文结合附图对本申请实施例的图像解码方法和编码方法进行了详细的介绍，下面结合图21至图24对对本申请实施例的图像解码装置和图像编码装置进行介绍。应理解，图21至图24中的图像解码装置能够执行本申请实施例的图像解码方法，图21至图24中的图像编码装置能够执行本申请实施例的图像编码方法。为了避免不必要的重复，下面在介绍本申请实施例的图像解码装置和图像编码装置时适当省略重复的描述。
图21是本申请实施例的图像解码装置的示意性框图。
图21所示的图像解码装置10000包括获取单元10001和处理单元10002。图像解码装置10000可以执行本申请实施例的图像解码方法，具体地，图像解码装置10000可以执行图11至图13所示的图像解码方法。
图22是本申请实施例的图像编码装置的示意性框图。
图22所示的图像编码装置11000包括获取单元11001和处理单元11002。图像编码装置11000可以执行本申请实施例的图像编码方法。具体地，图像编码装置11000可以执 行图14、图15和图18所示的图像编码方法。
图23是本申请实施例提供的图像解码装置的硬件结构示意图。
图23所示的图像解码装置12000(该图像解码装置12000具体可以是一种计算机设备)包括存储器12001、存储器12002、通信接口12003以及总线12004。其中，存储器12001、存储器12002、通信接口12003通过总线12004实现彼此之间的通信连接。
存储器12001可以是只读存储器(read only memory，ROM)，静态存储设备，动态存储设备或者随机存取存储器(random access memory，RAM)。存储器12001可以存储程序，当存储器12001中存储的程序被存储器12002执行时，存储器12002用于执行本申请实施例的图像解码方法的各个步骤。
存储器12002可以采用通用的中央处理器(central processing unit，CPU)，微处理器，应用专用集成电路(application specific integrated circuit，ASIC)，图形处理器(graphics processing unit，GPU)或者一个或多个集成电路，用于执行相关程序，以实现本申请方法实施例的图像解码方法。
存储器12002还可以是一种集成电路芯片，具有信号的处理能力。在实现过程中，本申请的图像解码方法的各个步骤可以通过存储器12002中的硬件的集成逻辑电路或者软件形式的指令完成。
上述存储器12002还可以是通用处理器、数字信号处理器(digital signal processing，DSP)、专用集成电路(ASIC)、现成可编程门阵列(FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件。可以实现或者执行本申请实施例中的公开的各方法、步骤及逻辑框图。
通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。结合本申请实施例所公开的方法的步骤可以直接体现为硬件译码处理器执行完成，或者用译码处理器中的硬件及软件模块组合执行完成。软件模块可以位于随机存储器，闪存、只读存储器，可编程只读存储器或者电可擦写可编程存储器、寄存器等本领域成熟的存储介质中。该存储介质位于存储器12001，处理器12002读取存储器12001中的信息，结合其硬件完成本图像解码装置中包括的单元所需执行的功能，或者执行本申请方法实施例的图像解码方法。
通信接口12003使用例如但不限于收发器一类的收发装置，来实现图像解码装置12000与其他设备或通信网络之间的通信。例如，可以通过通信接口12003获取待构建的神经网络的信息以及构建神经网络过程中需要的训练数据。
总线12004可包括在图像解码装置12000各个部件(例如，存储器12001、存储器12002、通信接口12003)之间传送信息的通路。
上述图像解码装置10000中的获取单元10001和处理单元10002相当于图像解码装置12000中的处理器12002。
图24是本申请实施例提供的图像编码装置的硬件结构示意图。图24所示的图像编码装置13000(该图像解码装置13000具体可以是一种计算机设备)包括存储器13001、处理器13002、通信接口13003以及总线13004。其中，存储器13001、处理器13002、通信接口13003通过总线13004实现彼此之间的通信连接。
上文中对图像解码装置12000中的各个模块的限定和解释同样也适用于图像编码装 置13000，这里不再详细描述。
上述存储器13001可以用于存储程序，处理器13002用于执行存储器13001存储的程序，当存储器13001存储的程序被执行时，处理器13002用于执行本申请实施例的图像编码方法的各个步骤。
另外，当图像编码装置13000对图像进行编码时，可以通过通信接口获取图像，然后对获取到的图像进行编码后得到编码后的数据，编码后的数据可以通过该通信接口13003传输给视频解码设备。
当图像编码装置13000对图像进行解码时，可以通过通信接口获取视频图像，然后对获取到的图像进行解码后得到待显示的图像。
上述图像编码装置11000中的获取单元11001和处理单元11002相当于图像编码装置13000中的处理器13002。
本领域普通技术人员可以意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以硬件还是软件方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
所属领域的技术人员可以清楚地了解到，为描述的方便和简洁，上述描述的***、装置和单元的具体工作过程，可以参考前述方法实施例中的对应过程，在此不再赘述。
在本申请所提供的几个实施例中，应该理解到，所揭露的***、装置和方法，可以通过其它的方式实现。例如，以上所描述的装置实施例仅仅是示意性的，例如，所述单元的划分，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式，例如多个单元或组件可以结合或者可以集成到另一个***，或一些特征可以忽略，或不执行。另一点，所显示或讨论的相互之间的耦合或直接耦合或通信连接可以是通过一些接口，装置或单元的间接耦合或通信连接，可以是电性，机械或其它的形式。
所述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。
另外，在本申请各个实施例中的各功能单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以两个或两个以上单元集成在一个单元中。
所述功能如果以软件功能单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本申请的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，服务器，或者网络设备等)执行本申请各个实施例所述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(read-only memory，ROM)、随机存取存储器(random access memory，RAM)、磁碟或者光盘等各种可以存储程序代码的介质。
以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员在本申请揭露的技术范围内，可轻易想到变化或替换，都应涵盖 在本申请的保护范围之内。因此，本申请的保护范围应以所述权利要求的保护范围为准。

Claims (34)

  1. 一种图像解码方法，其特征在于，包括：
    获取码流；
    根据所述码流，获取图像序列中的网格图像的残差图像，所述图像序列包括多个网格图像，所述多个网格图像满足第一条件；
    对所述图像序列中的网格图像进行帧间预测，得到所述图像序列中的网格图像的预测图像；
    根据所述图像序列中的网格图像的残差图像和所述图像序列中的网格图像的预测图像，得到所述图像序列中的网格图像。
  2. 如权利要求1所述的方法，其特征在于，所述第一条件为所述多个网格图像中的至少两个网格图像对应的地理位置之间的间距小于预设距离。
  3. 如权利要求1所述的方法，其特征在于，所述第一条件为所述多个网格图像中的至少两个网格图像的图像内容的相似度大于或者等于预设相似度。
  4. 如权利要求1所述的方法，其特征在于，所述第一条件为所述多个网格图像中的至少两个网格图像的图像内容对应于同一地理区域。
  5. 如权利要求2-4中任一项所述的方法，其特征在于，所述多个网格图像中的至少两个网格图像彼此之间为相邻帧的网格图像。
  6. 如权利要求1-5中任一项所述的方法，其特征在于，所述图像序列中的网格图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，所述方法还包括：
    对所述图像序列中的网格图像进行处理，得到处理后的网格图像；
    其中，所述图像序列中的网格图像的像素值的N个比特中第i个比特的取值，与所述处理后的图像序列中的网格图像的像素值的N个比特中的第i个比特的取值相反，所述图像序列中的网格图像的像素值的N个比特与所述处理后的图像序列中的网格图像的像素值的N个比特所处的位置相同，
    所述图像序列中的网格图像的像素值的N个比特位于所述图像序列中的网格图像的像素值的第一比特之后并且与所述第一比特相邻，所述第一比特是所述图像序列中的网格图像的像素值中取值为1并且位数最高的比特位，i和N均为正整数，i≤N，N＜M。
  7. 如权利要求1-5中任一项所述的方法，其特征在于，所述图像序列中的网格图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，所述方法还包括：
    对所述图像序列中的网格图像进行处理，得到处理后的网格图像；
    其中，所述处理后的图像序列中的网格图像的N个比特中的第1个比特的取值与所述图像序列中的网格图像的N个比特中的第1个比特的取值相反，所述处理后的图像序列中的网格图像的N个比特中的第i+1个比特的取值是所述图像序列中的网格图像的N个比特中的第i+1个比特的取值与处理后的图像序列中的网格图像的N个比特中的第i个比特进行异或处理的结果，
    所述图像序列中的网格图像的像素值的N个比特位于所述图像序列中的网格图像的像素值的第一比特之后并且与所述第一比特相邻，所述第一比特是所述图像序列中的网格图像的像素值中取值为1并且位数最高的比特位，或者，所述图像序列中的网格图像的像素值的N个比特位于所述图像序列中的网格图像的像素值的最高比特位之后并且与所述图像序列中的网格图像的像素值的最高比特位相邻，
    所述图像序列中的网格图像的像素值的N个比特与所述处理后的图像序列中的网格图像的像素值的N个比特所处的位置相同，第i个比特的位数高于第i+1个比特的位数，i和N均为正整数，i≤N，N＜M。
  8. 如权利要求1-5中任一项所述的方法，其特征在于，所述残差图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，所述根据所述图像序列中的网格图像的残差图像和所述图像序列中的网格图像的预测图像，得到所述图像序列中的网格图像，包括：
    对所述残差图像进行处理，得到处理后的残差图像；
    根据所述处理后的残差图像和所述图像序列中的网格图像的预测图像，得到所述图像序列中的网格图像；
    其中，所述残差图像的像素值的N个比特中的第i个比特的取值，与所述处理后的残差图像的像素值的N个比特中的第i个比特的取值相反，所述残差图像的像素值的N个比特与所述处理后的残差图像的像素值的N个比特所处的位置相同，
    所述残差图像的像素值的N个比特位于所述残差图像的像素值的第一比特之后并且与所述第一比特相邻，所述第一比特是所述残差图像的像素值中取值为1并且位数最高的比特位，i和N均为正整数，i≤N，N＜M。
  9. 如权利要求1-5中任一项所述的方法，其特征在于，所述残差图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，所述根据所述图像序列中的网格图像的残差图像和所述图像序列中的网格图像的预测图像，得到所述图像序列中的网格图像，包括：
    对所述残差图像进行处理，得到处理后的残差图像；
    根据所述处理后的残差图像和所述图像序列中的网格图像的预测图像，得到所述图像序列中的网格图像；
    其中，所述处理后的残差图像的N个比特中的第1个比特的取值与所述残差图像的N个比特中的第1个比特的取值相反，所述处理后的残差图像的N个比特中的第i+1个比特的取值是所述残差图像的N个比特中的第i+1个比特的取值与处理后的残差图像的N个比特中的第i个比特进行异或处理的结果，
    所述残差图像的像素值的N个比特位于所述残差图像的像素值的第一比特之后并且与所述第一比特相邻，所述第一比特是所述残差图像的像素值中取值为1并且位数最高的比特位，或者，所述残差图像的像素值的N个比特位于所述残差图像的像素值的最高比特位之后并且与所述残差图像的像素值的最高比特位相邻，
    所述残差图像的像素值的N个比特与所述处理后的残差图像的像素值的N个比特所处的位置相同，第i个比特的位数高于第i+1个比特的位数，i和N均为正整数，i≤N，N＜M。
  10. 如权利要求1-9中任一项所述的方法，其特征在于，所述根据所述码流，获取图像序列中的网格图像的残差图像，包括：
    对所述码流进行反变换、反量化和熵解码处理，得到所述残差图像。
  11. 如权利要求1-9中任一项所述的方法，其特征在于，所述根据所述码流，获取图像序列中的网格图像的残差图像，包括：
    对所述码流进行熵解码处理，得到所述残差图像。
  12. 如权利要求1-11中任一项所述的方法，其特征在于，所述码流是对定位图层进行编码得到的。
  13. 如权利要求12所述的方法，其特征在于，所述定位图层的像素值包含栅格化后的高程数据。
  14. 如权利要求1-13中任一项所述的方法，其特征在于，M的取值为8、10和12中的任意一个。
  15. 一种图像编码方法，其特征在于，包括：
    获取图像序列，所述图像序列包括多个网格图像，所述多个网格图像满足第一条件；
    对所述图像序列中的网格图像进行帧间预测，得到残差图像；
    对所述残差图像进行编码，得到编码码流。
  16. 如权利要求15所述的方法，其特征在于，所述第一条件为所述多个网格图像中的至少两个网格图像对应的地理位置之间的间距小于预设距离。
  17. 如权利要求15所述的方法，其特征在于，所述第一条件为所述多个网格图像中的至少两个网格图像的图像内容的相似度大于或者等于预设相似度。
  18. 如权利要求15所述的方法，其特征在于，所述第一条件为所述多个网格图像中的至少两个网格图像的图像内容对应于同一地理区域。
  19. 如权利要求16-18中任一项所述的方法，其特征在于，所述多个网格图像中的至少两个网格图像彼此间为相邻帧的网格图像。
  20. 如权利要求15-19中任一项所述的方法，其特征在于，所述图像序列中的网格图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，在对所述图像序列中的网格图像进行帧间预测之前，所述方法还包括：
    对所述图像序列中的网格图像进行处理，得到处理后的网格图像；
    其中，所述图像序列中的网格图像的像素值的N个比特中第i个比特的取值，与所述处理后的图像序列中的网格图像的像素值的N个比特中的第i个比特的取值相反，所述图像序列中的网格图像的像素值的N个比特与所述处理后的图像序列中的网格图像的像素值的N个比特所处的位置相同，
    所述图像序列中的网格图像的像素值的N个比特位于所述图像序列中的网格图像的像素值的第一比特之后并且与所述第一比特相邻，所述第一比特是所述图像序列中的网格图像的像素值中取值为1并且位数最高的比特位，i和N均为正整数，i≤N，N＜M；
    所述对所述图像序列中的网格图像进行帧间预测，包括：
    对所述处理后的网格图像进行帧间预测，得到所述残差图像。
  21. 如权利要求15-19中任一项所述的方法，其特征在于，所述图像序列中的网格图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，在对所 述图像序列中的网格图像进行帧间预测之前，所述方法还包括：
    对所述图像序列中的网格图像进行处理，得到处理后的网格图像；
    其中，所述处理后的图像序列中的网格图像的N个比特中的第1个比特的取值与所述图像序列中的网格图像的N个比特中的第1个比特的取值相反，所述处理后的图像序列中的网格图像的N个比特中的第i+1个比特的取值是所述图像序列中的网格图像的N个比特中的第i+1个比特的取值与处理后的图像序列中的网格图像的N个比特中的第i个比特进行异或处理的结果，
    所述图像序列中的网格图像的像素值的N个比特位于所述图像序列中的网格图像的像素值的第一比特之后并且与所述第一比特相邻，所述第一比特是所述图像序列中的网格图像的像素值中取值为1并且位数最高的比特位，或者，所述图像序列中的网格图像的像素值的N个比特位于所述图像序列中的网格图像的像素值的最高比特位之后并且与所述图像序列中的网格图像的像素值的最高比特位相邻，
    所述图像序列中的网格图像的像素值的N个比特与所述处理后的图像序列中的网格图像的像素值的N个比特所处的位置相同，第i个比特的位数高于第i+1个比特的位数，i和N均为正整数，i≤N，N＜M；
    所述对所述图像序列中的网格图像进行帧间预测，包括：
    对所述处理后的网格图像进行帧间预测，得到所述残差图像。
  22. 如权利要求15-19中任一项所述的方法，其特征在于，所述残差图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，所述对所述残差图像进行编码，得到编码码流，包括：
    对所述残差图像进行处理，得到处理后的残差图像；
    对所述处理后的残差图像进行编码，得到所述编码码流；
    其中，所述残差图像的像素值的N个比特中的第i个比特的取值，与所述处理后的残差图像的像素值的N个比特中的第i个比特的取值相反，所述残差图像的像素值的N个比特与所述处理后的残差图像的像素值的N个比特所处的位置相同，
    所述残差图像的像素值的N个比特位于所述残差图像的像素值的第一比特之后并且与所述第一比特相邻，所述第一比特是所述残差图像的像素值中取值为1并且位数最高的比特位，i和N均为正整数，i≤N，N＜M。
  23. 如权利要求15-19中任一项所述的方法，其特征在于，所述残差图像的像素值采用M个比特表示，每个比特的取值为0或1，M为大于1的整数，所述对所述残差图像进行编码，得到编码码流，包括：
    对所述残差图像进行处理，得到处理后的残差图像；
    对所述处理后的残差图像进行编码，得到所述编码码流；
    其中，所述残差图像的像素值的N个比特中第i个比特的取值，与所述处理后的残差图像的像素值的N个比特中的第i个比特的取值相反，所述处理后的残差图像的N个比特中的第i+1个比特的取值是所述残差图像的N个比特中的第i+1个比特的取值与处理后的残差图像的N个比特中的第i个比特进行异或处理的结果，
    所述残差图像的像素值的N个比特位于所述残差图像的像素值的第一比特之后并且与所述第一比特相邻，所述第一比特是所述残差图像的像素值中取值为1并且位数最高的 比特位，或者，所述残差图像的像素值的N个比特位于所述残差图像的像素值的最高比特位之后并且与所述残差图像的像素值的最高比特位相邻，
    所述残差图像的像素值的N个比特与所述处理后的残差图像的像素值的N个比特所处的位置相同，第i个比特的位数高于第i+1个比特的位数，i和N均为正整数，i≤N，N＜M。
  24. 如权利要求15-23中任一项所述的方法，其特征在于，对所述残差图像进行编码，得到编码码流，包括：
    对所述残差图像进行变换、量化和熵编码处理，得到编码码流。
  25. 如权利要求15-23中任一项所述的方法，其特征在于，对所述残差图像进行编码，得到编码码流，包括：
    对所述残差图像进行熵编码处理，得到编码码流。
  26. 如权利要求15-25中任一项所述的方法，其特征在于，所述图像序列中的网格图片来自定位图层。
  27. 如权利要求26所述的方法，其特征在于，所述定位图层的像素值包含栅格化后的高程数据。
  28. 如权利要求15-27中任一项所述的方法，其特征在于，M的取值为8、10和12中的任意一个。
  29. 一种图像解码装置，其特征在于，所述图像解码装置包括用于执行如权利要求1-14中任一项所述的方法的模块。
  30. 一种图像编码装置，其特征在于，所述图像编码装置包括用于执行如权利要求15-28中任一项所述的方法的模块。
  31. 一种图像解码装置，其特征在于，包括：
    存储器，用于存储程序；
    处理器，用于执行所述存储器存储的程序，当所述存储器存储的程序被所述处理器执行时，所述处理器执行如权利要求1-14中任一项所述的方法。
  32. 一种图像编码装置，其特征在于，包括：
    存储器，用于存储程序；
    处理器，用于执行所述存储器存储的程序，当所述存储器存储的程序被所述处理器执行时，所述处理器执行如权利要求15-28中任一项所述的方法。
  33. 一种电子设备，其特征在于，所述电子设备包括如权利要求31所述的图像解码装置和/或如权利要求32所述的图像编码装置。
  34. 一种计算机可读存储介质，其特征在于，所述计算机可读存储介质存储有可被处理器执行的计算机程序，当所述计算机程序被所述处理器执行时，所述处理器执行如权利要求1-14或者15-28中任一项所述的方法。
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