WO2013108688A1 - 画像処理装置および方法 - Google Patents
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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
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
- H04N19/124—Quantisation
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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
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/134—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or criterion affecting or controlling the adaptive coding
- H04N19/154—Measured or subjectively estimated visual quality after decoding, e.g. measurement of distortion
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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
- H04N19/10—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
- H04N19/186—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 a colour or a chrominance component
Definitions
- the present disclosure relates to an image processing apparatus and method, and relates to an image processing apparatus and method for improving the image quality of a color difference signal.
- MPEG compressed by orthogonal transform such as discrete cosine transform and motion compensation
- a device that conforms to a method such as Moving (Pictures Experts Group) has been widely used for both information distribution in broadcasting stations and information reception in general households.
- MPEG2 International Organization for Standardization
- IEC International Electrotechnical Commission
- MPEG2 was mainly intended for high-quality encoding suitable for broadcasting, but it did not support encoding methods with a lower code amount (bit rate) than MPEG1, that is, a higher compression rate. With the widespread use of mobile terminals, the need for such an encoding system is expected to increase in the future, and the MPEG4 encoding system has been standardized accordingly. Regarding the image coding system, the standard was approved as an international standard in December 1998 as ISO / IEC 14496-2.
- H.26L International Telecommunication Union Telecommunication Standardization Sector
- Q6 / 16 VCEG Video Coding Expert Group
- H.26L is known to achieve higher encoding efficiency than the conventional encoding schemes such as MPEG2 and MPEG4, although a large amount of calculation is required for encoding and decoding.
- Joint ⁇ ⁇ ⁇ ⁇ Model of Enhanced-Compression Video Coding has been implemented based on this H.26L and incorporating functions not supported by H.26L to achieve higher coding efficiency. It was broken.
- AVC Advanced Video Coding
- encoding unit a hierarchical structure including macroblocks and sub-macroblocks is defined as an encoding processing unit (encoding unit).
- this macroblock size is set to 16 pixels ⁇ 16 pixels for a large image frame such as UHD (Ultra High Definition: 4000 pixels ⁇ 2000 pixels), which is the target of the next generation encoding method. Not optimal.
- coding unit (Coding Unit)
- CU Coding Unit
- the quantization parameter for the color difference signal is generated by converting the quantization parameter for the luminance signal using an offset value called chroma_qp_index_offset.
- the quantization parameter for the color difference signal as the quantization parameter for the luminance signal, a larger value is set for a larger block so as to reduce the code amount.
- a block having a large orthogonal transform size is often a uniform image with little motion, and is frequently referred to by a motion vector. Therefore, by setting the quantization parameter for the color difference signal as described above, the block that is more likely to be referenced is quantized using a larger quantization parameter, and the image quality of the color difference signal is further improved. There was a risk of significant reduction.
- This disclosure has been made in view of such a situation, and an object thereof is to suppress a reduction in image quality of a color difference signal due to quantization.
- One aspect of the present disclosure provides an offset setting that sets an offset of a quantization parameter for a color difference signal based on a quantization parameter for a luminance signal according to the size or shape of a transform unit when orthogonally transforming image data And the quantization parameter for the chrominance signal obtained from the quantization parameter for the luminance signal using the offset set by the offset setting unit, and quantizing the orthogonal transform coefficient of the image data
- An image processing apparatus including a quantization unit.
- the offset setting unit can set the offset so that quantization is performed by a finer quantization step with respect to the larger transform unit.
- the offset setting unit can set the offset of the larger conversion unit to a smaller value.
- the offset setting unit quantizes the orthogonal transform coefficient having a size that is more easily referred to by a finer quantization step according to the bit rate of the encoded data obtained by encoding the image data.
- the offset can be set.
- the offset setting unit can correct the predetermined initial value of the offset according to the size of the conversion unit.
- the offset setting unit can set the offset value for a square conversion unit having the same or approximate size as the conversion unit as the offset for the rectangular conversion unit.
- the offset setting unit can set the offset in accordance with the size and shape of a conversion unit when orthogonally transforming the image data.
- One aspect of the present disclosure is also an image processing method of an image processing device, in which an offset setting unit performs quantization parameters on a luminance signal according to the size or shape of a transform unit when performing orthogonal transform on image data.
- the quantization parameter offset with respect to the color difference signal is set with respect to the color difference signal, and the quantization unit calculates the quantization parameter with respect to the color difference signal obtained from the quantization parameter with respect to the luminance signal using the set offset.
- an image processing method for quantizing orthogonal transform coefficients of the image data in which an offset setting unit performs quantization parameters on a luminance signal according to the size or shape of a transform unit when performing orthogonal transform on image data.
- Another aspect of the present disclosure provides an offset that sets an offset of a quantization parameter for a color difference signal based on a quantization parameter for a luminance signal according to the size or shape of a transform unit when orthogonally transforming image data.
- An image processing apparatus includes an inverse quantization unit that inversely quantizes a coefficient.
- Another aspect of the present disclosure is also an image processing method of an image processing device, in which an offset setting unit quantizes a luminance signal according to the size or shape of a transform unit when performing orthogonal transform on image data.
- a quantization parameter offset with respect to the color difference signal is set based on the parameter, and the inverse quantization unit uses the set offset to quantize the color difference signal obtained from the quantization parameter with respect to the luminance signal.
- the quantized orthogonal transform coefficient of the image data is inversely quantized using a parameter.
- an offset of a quantization parameter for a color difference signal is set based on a quantization parameter for a luminance signal in accordance with the size or shape of a transform unit when orthogonally transforming image data.
- An image comprising an offset setting unit, an encoding unit that encodes the image data, a transmission unit that transmits the offset set by the offset setting unit and the encoded data generated by the encoding unit It is a processing device.
- the transmission unit can transmit the offset set by the offset setting unit as a parameter set of the encoded data.
- the transmission unit can transmit a plurality of the offsets set by the offset setting unit as one parameter set.
- the transmission unit can transmit the offset set by the offset setting unit as a sequence parameter set of the encoded data.
- the transmission unit can transmit the offset set by the offset setting unit as a picture parameter set of the encoded data.
- the transmission unit can transmit the offset set by the offset setting unit as an adaptation parameter set of the encoded data.
- the transmission unit can transmit the offset set by the offset setting unit as a slice header of the encoded data.
- Still another aspect of the present disclosure is also an image processing method of an image processing device, in which an offset setting unit performs quantum quantization on a luminance signal according to the size or shape of a transform unit when orthogonally transforming image data.
- An offset of the quantization parameter with respect to the color difference signal is set with reference to the quantization parameter, the encoding unit encodes the image data, and the transmission unit sets the set offset and the generated encoded data.
- An image processing method for transmission in which an offset setting unit performs quantum quantization on a luminance signal according to the size or shape of a transform unit when orthogonally transforming image data.
- Still another aspect of the present disclosure provides an offset of a quantization parameter for a color difference signal based on a quantization parameter for a luminance signal, which is set according to the size or shape of a transform unit when orthogonally transforming image data.
- a receiving unit that receives the encoded data obtained by encoding the image data, a decoding unit that decodes the encoded data received by the receiving unit, and an extraction from the encoded data received by the receiving unit The image data obtained by decoding the encoded data by the decoding unit using the quantization parameter for the chrominance signal obtained from the quantization parameter for the luminance signal using the offset obtained.
- an inverse quantization unit that inversely quantizes the quantized orthogonal transform coefficient.
- Still another aspect of the present disclosure is also an image processing method of an image processing apparatus, in which a reception unit is set according to a size or a shape of a conversion unit when orthogonally transforming image data.
- a quantization parameter offset with respect to a color difference signal and encoded data obtained by encoding the image data are received, and a decoding unit decodes the received encoded data and performs inverse quantization.
- the encoding unit decodes the encoded data using the quantization parameter for the color difference signal obtained from the quantization parameter for the luminance signal using the offset extracted from the received encoded data.
- This is an image processing method for inversely quantizing the quantized orthogonal transform coefficient of the image data obtained in this way.
- the offset of the quantization parameter for the color difference signal is set based on the quantization parameter for the luminance signal according to the size or shape of the transform unit when orthogonally transforming the image data.
- the orthogonal transform coefficient of the image data is quantized using the quantization parameter for the color difference signal obtained from the quantization parameter for the luminance signal using the set offset.
- an offset of the quantization parameter for the color difference signal is set based on the quantization parameter for the luminance signal according to the size or shape of the transform unit when the image data is orthogonally transformed.
- the quantized orthogonal transform coefficient of the image data is inversely quantized using the quantization parameter for the color difference signal obtained from the quantization parameter for the luminance signal using the set offset.
- the quantization parameter offset for the color difference signal is set based on the quantization parameter for the luminance signal according to the size or shape of the transform unit when orthogonally transforming the image data. Then, the image data is encoded, and the set offset and the generated encoded data are transmitted.
- a quantization parameter for a color difference signal based on a quantization parameter for a luminance signal, which is set according to the size or shape of a transform unit when orthogonally transforming image data.
- An offset and encoded data obtained by encoding the image data are received, the received encoded data is decoded, and is obtained from the quantization parameter for the luminance signal using the offset extracted from the received encoded data.
- the quantized orthogonal transform coefficient of the image data obtained by decoding the encoded data is inversely quantized using the quantization parameter for the color difference signal.
- an image can be processed.
- it is possible to suppress a reduction in image quality of the color difference component.
- FIG. 20 is a block diagram illustrating a main configuration example of a computer. It is a block diagram which shows the main structural examples of a television apparatus. It is a block diagram which shows the main structural examples. It is a block diagram which shows the main structural examples of a recording / reproducing machine. It is a block diagram which shows the main structural examples of an imaging device. It is a block diagram which shows an example of scalable encoding utilization. It is a block diagram which shows the other example of scalable encoding utilization. It is a block diagram which shows the further another example of scalable encoding utilization.
- FIG. 1 is a block diagram illustrating a main configuration example of an image encoding device that is an image processing device to which the present technology is applied.
- the image encoding apparatus 100 shown in FIG. 1 is, for example, a HEVC (High Efficiency Video Coding) encoding scheme
- the image data of the moving image is encoded as in the H.264 and MPEG (Moving Picture Experts Group) 4 Part 10 (AVC (Advanced Video Coding)) coding system.
- H.264 and MPEG Motion Picture Experts Group
- AVC Advanced Video Coding
- the image encoding device 100 includes an A / D conversion unit 101, a screen rearrangement buffer 102, a calculation unit 103, an orthogonal transformation unit 104, a quantization unit 105, a lossless encoding unit 106, and a storage buffer. 107.
- the image coding apparatus 100 also includes an inverse quantization unit 108, an inverse orthogonal transform unit 109, a calculation unit 110, a loop filter 111, a frame memory 112, a selection unit 113, an intra prediction unit 114, a motion prediction / compensation unit 115, and a prediction.
- An image selection unit 116 and a rate control unit 117 are included.
- the A / D conversion unit 101 A / D converts the input image data, supplies the converted image data (digital data) to the screen rearrangement buffer 102, and stores it.
- the screen rearrangement buffer 102 rearranges the images of the frames in the stored display order in the order of frames for encoding in accordance with GOP (Group Of Picture), and the images in which the order of the frames is rearranged. This is supplied to the calculation unit 103.
- the screen rearrangement buffer 102 supplies each frame image to the calculation unit 103 for each predetermined partial area that is a processing unit (encoding unit) of the encoding process.
- the screen rearrangement buffer 102 supplies the image in which the order of the frames has been rearranged to the intra prediction unit 114 and the motion prediction / compensation unit 115 for each partial region.
- the calculation unit 103 subtracts the prediction image supplied from the intra prediction unit 114 or the motion prediction / compensation unit 115 via the prediction image selection unit 116 from the image read from the screen rearrangement buffer 102, and the difference information Is output to the orthogonal transform unit 104. For example, in the case of an image on which intra coding is performed, the calculation unit 103 subtracts the prediction image supplied from the intra prediction unit 114 from the image read from the screen rearrangement buffer 102. For example, in the case of an image on which inter coding is performed, the arithmetic unit 103 subtracts the predicted image supplied from the motion prediction / compensation unit 115 from the image read from the screen rearrangement buffer 102.
- the orthogonal transform unit 104 performs orthogonal transform such as discrete cosine transform and Karhunen-Loeve transform on the difference information supplied from the computation unit 103. Note that this orthogonal transformation method is arbitrary.
- the orthogonal transform unit 104 supplies the transform coefficient obtained by the orthogonal transform to the quantization unit 105.
- the quantization unit 105 quantizes the transform coefficient supplied from the orthogonal transform unit 104.
- the quantization unit 105 supplies the quantized transform coefficient to the lossless encoding unit 106.
- the lossless encoding unit 106 encodes the transform coefficient quantized by the quantization unit 105 using an arbitrary encoding method, and generates encoded data (bit stream). Since the coefficient data is quantized under the control of the rate control unit 117, the code amount of the encoded data becomes the target value set by the rate control unit 117 (or approximates the target value).
- the lossless encoding unit 106 acquires intra prediction information including information indicating an intra prediction mode from the intra prediction unit 114, and moves inter prediction information including information indicating an inter prediction mode, motion vector information, and the like. Obtained from the prediction / compensation unit 115. Further, the lossless encoding unit 106 acquires filter coefficients used in the loop filter 111 and the like.
- the lossless encoding unit 106 encodes these various types of information using an arbitrary encoding method, and includes (multiplexes) the information in the encoded data (bit stream).
- the lossless encoding unit 106 supplies the encoded data generated in this way to the storage buffer 107 for storage.
- Examples of the encoding method of the lossless encoding unit 106 include variable length encoding or arithmetic encoding.
- Examples of variable length coding include H.264.
- CAVLC Context-Adaptive Variable Length Coding
- Examples of arithmetic coding include CABAC (Context-Adaptive Binary Arithmetic Coding).
- the accumulation buffer 107 temporarily holds the encoded data supplied from the lossless encoding unit 106.
- the accumulation buffer 107 outputs the stored encoded data as a bit stream at a predetermined timing, for example, to a recording device (recording medium) or a transmission path (not shown) in the subsequent stage. That is, the encoded information is a device for decoding encoded data obtained by encoding image data by the image encoding device 100 (hereinafter also referred to as a decoding-side device) (for example, FIG. 11 described later).
- Image decoding apparatus 200 The accumulation buffer 107 temporarily holds the encoded data supplied from the lossless encoding unit 106.
- the accumulation buffer 107 outputs the stored encoded data as a bit stream at a predetermined timing, for example, to a recording device (recording medium) or a transmission path (not shown) in the subsequent stage. That is, the encoded information is a device for decoding encoded data obtained by encoding image data by the image encoding device 100 (her
- the transform coefficient quantized by the quantization unit 105 is also supplied to the inverse quantization unit 108.
- the inverse quantization unit 108 inversely quantizes the quantized transform coefficient by a method corresponding to the quantization by the quantization unit 105.
- the inverse quantization unit 108 supplies the obtained transform coefficient to the inverse orthogonal transform unit 109.
- the inverse orthogonal transform unit 109 performs inverse orthogonal transform on the transform coefficient supplied from the inverse quantization unit 108 by a method corresponding to the orthogonal transform performed by the orthogonal transform unit 104.
- the inversely orthogonally transformed output (difference information restored locally) is supplied to the calculation unit 110.
- the calculation unit 110 converts the inverse orthogonal transform result supplied from the inverse orthogonal transform unit 109, that is, locally restored difference information, into the intra prediction unit 114 or the motion prediction / compensation unit 115 via the predicted image selection unit 116. Are added to the predicted image to obtain a locally reconstructed image (hereinafter referred to as a reconstructed image).
- the reconstructed image is supplied to the loop filter 111 or the frame memory 112.
- the loop filter 111 includes a deblocking filter, an adaptive loop filter, and the like, and appropriately performs a filtering process on the reconstructed image supplied from the calculation unit 110.
- the loop filter 111 removes block distortion of the reconstructed image by performing deblocking filter processing on the reconstructed image.
- the loop filter 111 improves the image quality by performing loop filter processing using a Wiener filter on the deblocking filter processing result (reconstructed image from which block distortion has been removed). I do.
- the loop filter 111 may further perform other arbitrary filter processing on the reconstructed image. Further, the loop filter 111 can supply information such as filter coefficients used for the filter processing to the lossless encoding unit 106 and encode it as necessary.
- the loop filter 111 supplies a filter processing result (hereinafter referred to as a decoded image) to the frame memory 112.
- the frame memory 112 stores the reconstructed image supplied from the calculation unit 110 and the decoded image supplied from the loop filter 111, respectively.
- the frame memory 112 supplies the stored reconstructed image to the intra prediction unit 114 via the selection unit 113 at a predetermined timing or based on a request from the outside such as the intra prediction unit 114.
- the frame memory 112 also stores the decoded image stored at a predetermined timing or based on a request from the outside such as the motion prediction / compensation unit 115 via the selection unit 113. 115.
- the selection unit 113 indicates the supply destination of the image output from the frame memory 112. For example, in the case of intra prediction, the selection unit 113 reads an image (reconstructed image) that has not been subjected to filter processing from the frame memory 112 and supplies it to the intra prediction unit 114 as peripheral pixels.
- the selection unit 113 reads out an image (decoded image) that has been filtered from the frame memory 112, and supplies it as a reference image to the motion prediction / compensation unit 115.
- the intra prediction unit 114 When the intra prediction unit 114 acquires an image (peripheral image) of a peripheral region located around the processing target region from the frame memory 112, the intra prediction unit 114 basically uses a pixel value of the peripheral image to predict a prediction unit (PU ( Prediction (Unit))) is used as a processing unit to perform intra prediction (in-screen prediction) for generating a predicted image.
- the intra prediction unit 114 performs this intra prediction in a plurality of modes (intra prediction modes) prepared in advance.
- the intra prediction unit 114 generates a prediction image in all candidate intra prediction modes, evaluates the cost function value of each prediction image using the input image supplied from the screen rearrangement buffer 102, and determines the optimum Select a mode.
- the intra prediction unit 114 selects the optimal intra prediction mode, the intra prediction unit 114 supplies the predicted image generated in the optimal mode to the predicted image selection unit 116.
- the intra prediction unit 114 appropriately supplies intra prediction information including information related to intra prediction, such as an optimal intra prediction mode, to the lossless encoding unit 106 to be encoded.
- the motion prediction / compensation unit 115 basically uses the input image supplied from the screen rearrangement buffer 102 and the reference image supplied from the frame memory 112 as a processing unit, using PU (inter PU) as a processing unit. (Inter prediction) is performed, motion compensation processing is performed according to the detected motion vector, and a predicted image (inter predicted image information) is generated.
- the motion prediction / compensation unit 115 performs such inter prediction in a plurality of modes (inter prediction modes) prepared in advance.
- the motion prediction / compensation unit 115 generates a prediction image in all candidate inter prediction modes, evaluates the cost function value of each prediction image, and selects an optimal mode.
- the motion prediction / compensation unit 115 supplies the predicted image generated in the optimal mode to the predicted image selection unit 116.
- the motion prediction / compensation unit 115 supplies inter prediction information including information related to inter prediction, such as an optimal inter prediction mode, to the lossless encoding unit 106 to be encoded.
- the predicted image selection unit 116 selects a supply source of a predicted image to be supplied to the calculation unit 103 or the calculation unit 110.
- the prediction image selection unit 116 selects the intra prediction unit 114 as a supply source of the prediction image, and supplies the prediction image supplied from the intra prediction unit 114 to the calculation unit 103 and the calculation unit 110.
- the predicted image selection unit 116 selects the motion prediction / compensation unit 115 as a supply source of the predicted image, and calculates the predicted image supplied from the motion prediction / compensation unit 115 as the calculation unit 103. To the arithmetic unit 110.
- the rate control unit 117 controls the quantization operation rate of the quantization unit 105 based on the code amount of the encoded data stored in the storage buffer 107 so that overflow or underflow does not occur.
- the image encoding device 100 includes a color difference quantization offset setting unit 121.
- the orthogonal transformation process of the orthogonal transformation unit 104 is performed for each region of a predetermined size (also referred to as an orthogonal transformation unit, a transformation unit, or a TU (Transform Unit)).
- the size (size) of the orthogonal transform unit (transform unit) is selected from a plurality of candidates prepared in advance. That is, the orthogonal transform unit 104 performs orthogonal transform using each size as a transform unit, and sets the size with the smallest cost function value (size with the smallest code amount) as the transform unit size (also referred to as optimum TU size). Select as.
- the orthogonal transform unit 104 supplies the orthogonal transform coefficient obtained by the orthogonal transform process performed for each transform unit of the optimal TU size to the quantization unit 105. Further, the orthogonal transform unit 104 supplies information regarding the optimum TU size to the color difference quantization offset setting unit 121.
- the color difference quantization offset setting unit 121 sets chroma_qp_index_offset, which is an offset value of the quantization parameter for the color difference signal, based on the quantization parameter for the luminance signal according to the optimum TU size.
- the color difference quantization offset setting unit 121 supplies the chroma_qp_index_offset set in this way to the quantization unit 105 and the inverse quantization unit 108.
- the quantization unit 105 obtains a quantization parameter for the color difference signal using the chroma_qp_index_offset supplied from the color difference quantization offset setting unit 121, and is supplied from the orthogonal transform unit 104 using the quantization parameter for the color difference signal. Quantizes the orthogonal transform coefficient of the color difference signal.
- the inverse quantization unit 108 obtains a quantization parameter for the color difference signal using chroma_qp_index_offset supplied from the color difference quantization offset setting unit 121, and is supplied from the quantization unit 105 using the quantization parameter for the color difference signal.
- the quantized data (quantized transform coefficient) of the chrominance signal is dequantized.
- the quantization unit 105 performs quantization, which is processing for rounding the result obtained by dividing the coefficient data by the quantization step to an integer value.
- the quantization unit 105 can reduce the coefficient value by this quantization. Therefore, the image coding apparatus 100 can reduce the code amount by coding the coefficient (quantized value) of the quantization result as compared with the case of coding the orthogonal transform coefficient before quantization. .
- the code amount can be adjusted according to the size of the quantization step. Therefore, the bit stream rate can be controlled by controlling the size of the quantization step.
- a quantization step having the same size as the quantization step used for quantization is required.
- the quantization parameter is transmitted to the decoding side device instead of the quantization step.
- a predetermined relationship is defined in advance between the quantization step (QS) and the quantization parameter (QP). For example, in the case of AVC, a relationship such as the following formula (1) is defined.
- FIG. 3 is a graph showing an example of the relationship between the quantization step (QS) and the quantization parameter (QP). As shown in the graph of FIG. 3, when the quantization parameter is increased by 6, the quantization step is doubled.
- the range of values that the quantization step can take is defined in advance according to the desired range of the quantization step. For example, in the case of AVC, values from 0 to 51 are defined as quantization parameter values so that the maximum value of the quantization step is 256 times the minimum value.
- the quantization parameter QP c for the color difference signal is given as shown in the table shown in FIG. 3 according to the quantization parameter QP Y for the luminance signal and the predetermined parameter QP I.
- This parameter QP I is expressed by the following equation (2) using a parameter called chroma_qp_index_offset, which is included in the Picture Parameter Set, and which is based on the quantization parameter for the luminance signal and is the quantization parameter offset value for the chrominance signal. ).
- the user can control the quantization value for the color difference signal by adjusting the value of chroma_qp_index_offset.
- chroma_qp_index_offset can be set independently for each of the Cb signal and the Cr signal.
- encoding unit a hierarchical structure of macroblocks and sub-macroblocks is defined as an encoding processing unit (encoding unit).
- this macroblock size is set to 16 pixels ⁇ 16 pixels for a large image frame such as UHD (Ultra High Definition; 4000 pixels ⁇ 2000 pixels), which is the target of the next generation encoding method. Not optimal.
- coding unit (Coding Unit)
- CU Coding Unit
- This coding unit is also called a coding tree block (CTB (Coding Tree Block)), and is a partial region of a multilayer structure of a picture unit image that plays the same role as a macroblock in AVC. That is, CU is a unit (encoding unit) of encoding processing. While the size of the macroblock is fixed to 16 ⁇ 16 pixels, the size of the CU is not fixed, and is specified in the image compression information in each sequence.
- CTB Coding Tree Block
- a CU having the largest size is referred to as a large coding unit (LCU (Largest Coding Unit)), and a CU having the smallest size is referred to as a smallest coding unit (SCU (Smallest Coding Unit)). That is, the LCU is the maximum coding unit, and the SCU is the minimum coding unit.
- the sizes of these areas are specified, It is a square and is limited to a size represented by a power of 2. That is, each area obtained by dividing a (square) CU at a certain level into 2 ⁇ 2 is a (square) CU one level below.
- Fig. 4 shows an example of coding unit (Coding Unit) defined in HEVC.
- split_flag When the value of split_flag is “1”, the CU having the size of 2Nx2N is divided into CUs having the size of NxN that is one level below.
- the CU is divided into prediction units (Prediction Units (PU)) that are regions (partial regions of images in units of pictures) that are processing units of intra or inter prediction, and are regions that are processing units of orthogonal transformation It is divided into transform units (Transform Unit (TU)), which is (a partial area of an image in units of pictures).
- Prediction Units PU
- TU Transform Unit
- inter prediction PU Inter Prediction Unit
- 4N sizes of 2Nx2N, 2NxN, Nx2N, and NxN can be set for a 2Nx2N CU.
- one PU of the same size as that CU two PUs obtained by dividing the CU vertically or horizontally, or four PUs obtained by dividing the CU into two vertically and horizontally respectively.
- the image encoding apparatus 100 performs each process related to encoding using a partial region of an image in units of pictures as a processing unit.
- a processing unit uses a CU defined by HEVC as a coding unit. That is, LCU is the maximum coding unit and SCU is the minimum coding unit.
- the processing unit of each encoding process by the image encoding apparatus 100 is not limited to this, and is arbitrary.
- a macroblock or sub-macroblock defined by AVC may be used as a processing unit.
- the “(partial) area” includes all the above-mentioned various areas (for example, macroblock, sub-macroblock, LCU, CU, SCU, PU, TU, etc.). May be). Of course, units other than those described above may be included, and units that are impossible according to the content of the description are appropriately excluded.
- the quantization parameter (QP) used for quantization in the encoding device is transmitted to the decoding device.
- QP quantization parameter
- the CU has a hierarchical structure, and a plurality of sizes of CUs can be formed in the LCU.
- the image encoding apparatus 100 can transmit the quantization parameter only for a CU having an arbitrary size or larger.
- max_cu_qp_delta_depth which is a syntax element in the picture parameter set shown in FIG.
- the quantization parameter of the target CU instead of the quantization parameter of the target CU that is the processing target CU, the quantization parameter of the target CU and the quantization parameters of the CUs around the target CU A difference value (difference quantization parameter) is transmitted.
- FIG. 6 is a diagram illustrating an example of the syntax of the conversion coefficient. As illustrated in FIG. 6, for example, a parameter cu_qp_delta representing the differential quantization parameter of the target CU is transmitted for each CU that is greater than or equal to the size specified by the syntax element max_cu_qp_delta_depth.
- the difference quantization parameter cu_qp_delta is calculated according to the following equation (3).
- LeftQP is the quantization parameter of the CU located to the left of the target CU
- PrevQP is the quantization parameter of the CU processed immediately before the target CU. That is, the difference value between the quantization parameter of the attention CU and the quantization parameter of the CU processed immediately before the attention CU is transmitted.
- the quantization parameter for the color difference signal is generated from the quantization parameter for the luminance signal. Accordingly, the quantization parameter for the color difference signal is set to a larger value for a larger block so as to further reduce the code amount, similarly to the quantization parameter for the luminance signal.
- a block having a large orthogonal transform size is often a uniform image with little motion, and is frequently referred to by a motion vector. Therefore, by setting the quantization parameter for the color difference signal as described above, the block that is more likely to be referenced is quantized using a larger quantization parameter, and the image quality of the color difference signal is further improved. There was a risk of significant reduction.
- the chrominance quantization offset setting unit 121 sets the value of chroma_qp_index_offset according to the size of the orthogonal transform unit, and quantization is performed with a finer quantization step for a larger transform unit (TU). Like that. That is, the chroma_qp_index_offset of a larger conversion unit (TU) is set to a smaller value.
- the color difference quantization offset setting unit 121 can improve the image quality of the TU that is referred to more frequently. That is, the color difference quantization offset setting unit 121 can suppress a reduction in image quality of the color difference signal due to quantization. Thereby, the image coding apparatus 100 can improve the coding efficiency of the encoded data to be output.
- FIG. 7 is a block diagram illustrating a main configuration example of the orthogonal transform unit 104 and the quantization unit 105 of FIG.
- the orthogonal transform unit 104 includes a 4 ⁇ 4 orthogonal transform unit 151, an 8 ⁇ 8 orthogonal transform unit 152, a 16 ⁇ 16 orthogonal transform unit 153, a 4 ⁇ 4 cost function calculation unit 154, and an 8 ⁇ 8.
- a cost function calculating unit 155, a 16 ⁇ 16 cost function calculating unit 156, and a TU size determining unit 157 are included.
- the 4 ⁇ 4 orthogonal transform unit 151 performs orthogonal transform on the difference image supplied from the calculation unit 103 using 4 ⁇ 4 pixels as an orthogonal transform unit (TU).
- the 4 ⁇ 4 orthogonal transform unit 151 supplies the orthogonal transform coefficient obtained as a result of the orthogonal transform to the 4 ⁇ 4 cost function calculation unit 154.
- the 4 ⁇ 4 cost function calculation unit 154 uses the orthogonal transform coefficient supplied from the 4 ⁇ 4 orthogonal transform unit 151 to calculate a cost function value when the size of the orthogonal transform unit (TU) is 4 ⁇ 4 pixels. To do.
- the 4 ⁇ 4 cost function calculation unit 154 supplies the calculated cost function value to the TU size determination unit 157 together with the orthogonal transform coefficient supplied from the 4 ⁇ 4 orthogonal transform unit 151.
- the 8 ⁇ 8 orthogonal transform unit 152 orthogonally transforms the difference image supplied from the calculation unit 103 using 8 ⁇ 8 pixels as an orthogonal transform unit (TU).
- the 8 ⁇ 8 orthogonal transform unit 152 supplies the orthogonal transform coefficient obtained as a result of the orthogonal transform to the 8 ⁇ 8 cost function calculation unit 155.
- the 8 ⁇ 8 cost function calculation unit 155 uses the orthogonal transform coefficient supplied from the 8 ⁇ 8 orthogonal transform unit 152 to calculate a cost function value when the size of the orthogonal transform unit (TU) is 8 ⁇ 8 pixels. To do.
- the 8 ⁇ 8 cost function calculation unit 155 supplies the calculated cost function value to the TU size determination unit 157 together with the orthogonal transform coefficient supplied from the 8 ⁇ 8 orthogonal transform unit 152.
- the 16 ⁇ 16 orthogonal transform unit 153 performs orthogonal transform on the difference image supplied from the computation unit 103 using 16 ⁇ 16 pixels as an orthogonal transform unit (TU).
- the 16 ⁇ 16 orthogonal transform unit 153 supplies the orthogonal transform coefficient obtained as a result of the orthogonal transform to the 16 ⁇ 16 cost function calculation unit 156.
- the 16 ⁇ 16 cost function calculation unit 156 uses the orthogonal transform coefficient supplied from the 16 ⁇ 16 orthogonal transform unit 153 to calculate a cost function value when the size of the orthogonal transform unit (TU) is 16 ⁇ 16 pixels. To do.
- the 16 ⁇ 16 cost function calculating unit 156 supplies the calculated cost function value to the TU size determining unit 157 together with the orthogonal transform coefficient supplied from the 16 ⁇ 16 orthogonal transform unit 153.
- the TU size determination unit 157 compares the cost function values corresponding to the supplied orthogonal transform units of each size, and determines the size having the smallest value (the code amount is the smallest) as the optimum orthogonal transform unit (TU). As the size (optimal TU size).
- the orthogonal transform unit 104 performs orthogonal transform for each of the candidates for the size of the orthogonal transform unit prepared in advance, obtains a cost function value, and selects an optimal TU size based on the value.
- each candidate size of 4 ⁇ 4 pixels, 8 ⁇ 8 pixels, and 16 ⁇ 16 pixels are prepared as candidates for the size of the orthogonal transform unit.
- the size of each candidate is arbitrary.
- an orthogonal transform unit larger than the above-described size, such as 32 ⁇ 32 pixels, may be included in the candidate.
- rectangular orthogonal transform units such as 4 ⁇ 8 pixels and 16 ⁇ 8 pixels may be included in the candidates.
- the orthogonal transform unit 104 may perform orthogonal transform in this way for all candidates prepared in advance, obtain a cost function value, and select an optimal TU size based on the value. Depending on the case, some candidates may be selected, and only some of the candidates may be subjected to orthogonal transformation, cost function values may be obtained, and an optimum TU size may be selected therefrom. For example, when the size of the orthogonal transform unit needs to be limited at the screen edge or the slice boundary, the orthogonal transform unit 104 may select an allowable size candidate from the candidates prepared in advance. Good.
- the TU size determination unit 157 supplies information indicating the selected optimum TU size to the color difference quantization offset setting unit 121. Also, the TU size determination unit 157 quantizes an orthogonal transform coefficient obtained by orthogonally transforming the difference image supplied from the computation unit 103 for each orthogonal transform unit having the optimal TU size, and a quantization unit 105 (quantization processing unit 172). ).
- the color difference quantization offset setting unit 121 sets chroma_qp_index_offset according to the optimum TU size supplied from the orthogonal transform unit 104. At this time, the color difference quantization offset setting unit 121 sets a smaller value for a larger TU.
- the color difference quantization offset setting unit 121 may correct the preset initial value of chroma_qp_index_offset according to the optimal TU size.
- the initial value of chroma_qp_index_offset is set in advance for each predetermined unit, for example, for each profile or level, for each sequence, for each picture, or for each slice.
- a predetermined fixed value may be defined in advance as an initial value of chroma_qp_index_offset.
- the color difference quantization offset setting unit 121 determines the correction amount of chroma_qp_index_offset according to the optimum TU size. For example, as shown in FIG. 8, the correction amount is set to ⁇ 1 ( ⁇ 1 ⁇ 0), 0, ⁇ 2 (for the candidates of 16 ⁇ 16 pixels, 8 ⁇ 8 pixels, and 4 ⁇ 4 pixels, respectively. ⁇ 2 ⁇ 0).
- the color difference quantization offset setting unit 121 selects a correction amount corresponding to the optimal TU size from these, and corrects the initial value of chroma_qp_index_offset with the correction amount.
- 8 ⁇ 8 pixels are used as a reference (TU size corresponding to the initial value of chroma_qp_index_offset), and correction is performed for other TU sizes.
- this reference TU size is arbitrary. It is. For example, 4 ⁇ 4 pixels may be the reference (correction amount 0), and 16 ⁇ 16 pixels may be the reference (correction amount 0).
- This correction amount may be set in advance for all TU size candidates, but may be obtained by a predetermined calculation for some or all candidates. This calculation may be any calculation as long as the correction amount is determined (dependent) on the TU size. Further, the calculation may be such that the correction amount depends on parameters other than the TU size. By doing so, it is possible to reduce the storage capacity necessary for storing the correction amount candidates.
- chroma_qp_index_offset is preset for each TU size candidate, and the color difference quantization offset setting unit 121 may only select chroma_qp_index_offset corresponding to the optimal TU size. By doing in this way, the process of the color difference quantization offset setting part 121 becomes easy. However, many candidates for chroma_qp_index_offset must be stored, and a larger storage area is required than when the correction amount is stored.
- the color difference quantization offset setting unit 121 may calculate chroma_qp_index_offset by a predetermined calculation according to the optimum TU size. This calculation may be any calculation as long as the value of chroma_qp_index_offset is determined (depends on) according to the TU size. By doing in this way, it is not necessary to memorize chroma_qp_index_offset and its correction amount, so that the necessary storage capacity can be reduced.
- the color difference quantization offset setting unit 121 can calculate chroma_qp_index_offset according to the optimum TU size by an arbitrary method.
- the color difference quantization offset setting unit 121 supplies chroma_qp_index_offset calculated as described above to the quantization unit 105 (color difference quantization value determination unit 171).
- the quantization unit 105 includes a color difference quantized value determination unit 171 and a quantization processing unit 172.
- the color difference quantization value determination unit 171 uses the above-described equation (2) and the table shown in FIG. 3 to calculate the color difference signal from chroma_qp_index_offset supplied from the color difference quantization offset setting unit 121 and the quantization parameter for the luminance signal. Find the quantization parameter for.
- the color difference quantization value determination unit 171 supplies the quantization parameter for the obtained color difference signal to the quantization processing unit 172.
- the quantization processing unit 172 quantizes the orthogonal transformation coefficient of the luminance signal supplied from the orthogonal transformation unit 104 (TU size determination unit 157) using a quantization parameter for the luminance signal. Also, the quantization processing unit 172 sets the orthogonal transformation coefficient of the color difference signal supplied from the orthogonal transformation unit 104 (TU size determination unit 157) and the quantization parameter for the color difference signal supplied from the color difference quantization value determination unit 171. Use to quantize.
- the quantization parameter for this color difference signal is set to a smaller value for a larger TU, so that the quantization processing unit 172 suppresses a reduction in image quality of the color difference signal.
- Quantization can be performed as follows.
- the quantization processing unit 172 supplies the orthogonal transform coefficient thus quantized to the lossless encoding unit 106 and the inverse quantization unit 108.
- the color difference quantization offset setting unit 121 supplies chroma_qp_index_offset to the inverse quantization unit 108 as well.
- the inverse quantization unit 108 performs inverse quantization using this chroma_qp_index_offset, but the processing is the same as that of the inverse quantization unit of the decoding side device (for example, the image decoding device 200 in FIG. 11), and therefore the description thereof will be given. Is omitted (the description of the decoding side apparatus described later can be applied).
- the correction amount delta 1 and delta 2 shown in FIG. 8 may be the same value, or may be different from each other.
- the TU size depends on the bit rate, that is, the value of the quantization parameter. That is, at a lower bit rate, 16 ⁇ 16 pixels are easily selected as the optimal TU size, and at a high bit rate, 4 ⁇ 4 pixels are easily selected as the optimal TU size.
- the image coding apparatus 100 can further improve the coding efficiency by individually adjusting the values of ⁇ 1 and ⁇ 2 according to the quantization parameter.
- step S101 the A / D converter 101 performs A / D conversion on the input image.
- step S102 the screen rearrangement buffer 102 stores the A / D converted image, and rearranges the picture from the display order to the encoding order.
- step S103 the intra prediction unit 114 performs an intra prediction process in the intra prediction mode.
- step S104 the motion prediction / compensation unit 115 performs an inter motion prediction process for performing motion prediction and motion compensation in the inter prediction mode.
- step S105 the predicted image selection unit 116 determines the optimal prediction mode based on the cost function values output from the intra prediction unit 114 and the motion prediction / compensation unit 115. That is, the predicted image selection unit 116 selects one of the predicted image generated by the intra prediction unit 114 and the predicted image generated by the motion prediction / compensation unit 115.
- step S106 the calculation unit 103 calculates a difference between the image rearranged by the process of step S102 and the predicted image selected by the process of step S105.
- the data amount of the difference data is reduced compared to the original image data. Therefore, the data amount can be compressed as compared with the case where the image is encoded as it is.
- step S107 the orthogonal transform unit 104, the quantization unit 105, and the color difference quantization offset setting unit 121 execute orthogonal transform quantization processing, orthogonally transform the difference information generated by the processing in step S106, and further Quantize the orthogonal transform.
- step S107 The difference information quantized by the process of step S107 is locally decoded as follows. That is, in step S108, the inverse quantization unit 108 inversely quantizes the orthogonal transform coefficient quantized by the process in step S107 by a method corresponding to the quantization. In step S109, the inverse orthogonal transform unit 109 performs inverse orthogonal transform on the orthogonal transform coefficient obtained by the process of step S108 by a method corresponding to the process of step S107.
- step S110 the calculation unit 110 adds the predicted image to the locally decoded difference information, and generates a locally decoded image (an image corresponding to the input to the calculation unit 103).
- step S111 the loop filter 111 filters the image generated by the process of step S110. Thereby, block distortion and the like are removed.
- step S112 the frame memory 112 stores an image from which block distortion has been removed by the process of step S111. It should be noted that an image that has not been filtered by the loop filter 111 is also supplied from the calculation unit 110 and stored in the frame memory 112.
- the image stored in the frame memory 112 is used for the processing in step S103 and the processing in step S104.
- step S113 the lossless encoding unit 106 encodes the transform coefficient quantized by the processing in step S107, and generates encoded data. That is, lossless encoding such as variable length encoding or arithmetic encoding is performed on the difference image (secondary difference image in the case of inter).
- the lossless encoding unit 106 encodes information related to the prediction mode of the prediction image selected by the process of step S105, and adds the encoded information to the encoded data obtained by encoding the difference image. For example, when the intra prediction mode is selected, the lossless encoding unit 106 encodes the intra prediction mode information. For example, when the inter prediction mode is selected, the lossless encoding unit 106 encodes the inter prediction mode information. These pieces of information are added (multiplexed) to the encoded data as header information, for example.
- step S114 the accumulation buffer 107 accumulates the encoded data generated by the process in step S113.
- the encoded data stored in the storage buffer 107 is read out as appropriate, and transmitted to a decoding-side device via an arbitrary transmission path (including not only a communication path but also a storage medium).
- step S115 the rate control unit 117 controls the quantization operation rate of the quantization unit 105 so that overflow or underflow does not occur based on the compressed image accumulated in the accumulation buffer 107 by the process of step S114. .
- step S115 When the process of step S115 is finished, the encoding process is finished.
- the 4 ⁇ 4 orthogonal transform unit 151, the 8 ⁇ 8 orthogonal transform unit 152, and the 16 ⁇ 16 orthogonal transform unit 153 of the orthogonal transform unit 104 orthogonalize each size in step S 151.
- Orthogonal transformation is performed as a transformation unit (TU).
- step S152 the 4 ⁇ 4 cost function calculation unit 154, the 8 ⁇ 8 cost function calculation unit 155, and the 16 ⁇ 16 cost function calculation unit 156 perform orthogonal transform results (orthogonal) of each TU size obtained by the process of step S151.
- the cost function for each TU size is calculated using the conversion coefficient.
- step S153 the TU size determination unit 157 determines the optimal TU size using the cost function value for each TU size calculated in step S152.
- step S154 the color difference quantization offset setting unit 121 determines chroma_qp_index_offset according to the optimum TU size determined in step S153.
- step S155 the orthogonal transform unit 104 orthogonally transforms the difference image with the optimum TU size determined in step S153.
- the orthogonal transform may be performed again.
- the TU size determination unit 157 selects an orthogonal transform coefficient corresponding to the optimum TU size from among the orthogonal transform coefficients corresponding to each TU size obtained in step S151. You may make it select.
- step S156 the quantization processing unit 172 sets a quantization parameter for the luminance component (luminance signal) of the image to be encoded.
- step S157 the color difference quantization value determination unit 171 sets a quantization parameter for the color difference component (color difference signal) of the encoding target image based on chroma_qp_index_offset.
- step S158 the quantization processing unit 172 quantizes the orthogonal transform coefficient of the luminance signal using the quantization parameter for the luminance signal set in step S156. In addition, the quantization processing unit 172 quantizes the orthogonal transform coefficient of the color difference signal using the quantization parameter for the color difference signal set in step S157.
- the quantization unit 105 ends the orthogonal transform quantization processing, returns the processing to step S107 in FIG. 9, and repeats the subsequent processing.
- the image encoding device 100 can suppress a reduction in image quality of the color difference signal due to quantization. Thereby, the image coding apparatus 100 can improve the coding efficiency of the encoded data to be output.
- FIG. 11 is a block diagram illustrating a main configuration example of an image decoding device that is an image processing device to which the present technology is applied.
- An image decoding apparatus 200 shown in FIG. 11 corresponds to the above-described image encoding apparatus 100, correctly decodes a bit stream (encoded data) generated by encoding image data by the image encoding apparatus 100, and generates a decoded image. Is generated.
- the image decoding apparatus 200 includes a storage buffer 201, a lossless decoding unit 202, an inverse quantization unit 203, an inverse orthogonal transform unit 204, a calculation unit 205, a loop filter 206, a screen rearrangement buffer 207, and a D A / A converter 208 is included.
- the image decoding apparatus 200 includes a frame memory 209, a selection unit 210, an intra prediction unit 211, a motion prediction / compensation unit 212, and a selection unit 213.
- the accumulation buffer 201 accumulates the transmitted encoded data, and supplies the encoded data to the lossless decoding unit 202 at a predetermined timing.
- the lossless decoding unit 202 decodes the information supplied from the accumulation buffer 201 and encoded by the lossless encoding unit 106 in FIG. 1 by a method corresponding to the encoding method of the lossless encoding unit 106.
- the lossless decoding unit 202 supplies the quantized coefficient data of the difference image obtained by decoding to the inverse quantization unit 203.
- the lossless decoding unit 202 refers to information on the optimal prediction mode obtained by decoding the encoded data, and determines whether the intra prediction mode or the inter prediction mode is selected as the optimal prediction mode. . That is, the lossless decoding unit 202 determines whether the prediction mode employed in the transmitted encoded data is intra prediction or inter prediction.
- the lossless decoding unit 202 supplies information on the prediction mode to the intra prediction unit 211 or the motion prediction / compensation unit 212 based on the determination result.
- the lossless decoding unit 202 is intra prediction information, which is information about the selected intra prediction mode supplied from the encoding side. Is supplied to the intra prediction unit 211.
- the lossless decoding unit 202 is an inter that is information about the selected inter prediction mode supplied from the encoding side. The prediction information is supplied to the motion prediction / compensation unit 212.
- the inverse quantization unit 203 uses the method corresponding to the quantization method of the quantization unit 105 in FIG. 1 (similar to the inverse quantization unit 108) for the quantized coefficient data obtained by decoding by the lossless decoding unit 202. Method).
- the inverse quantization unit 203 supplies the inversely quantized coefficient data to the inverse orthogonal transform unit 204.
- the inverse orthogonal transform unit 204 performs inverse orthogonal transform on the coefficient data supplied from the inverse quantization unit 203 in a method corresponding to the orthogonal transform method of the orthogonal transform unit 104 in FIG.
- the inverse orthogonal transform unit 204 obtains a difference image corresponding to the difference image before being orthogonally transformed in the image encoding device 100 by the inverse orthogonal transform process.
- the difference image obtained by the inverse orthogonal transform is supplied to the calculation unit 205.
- a prediction image is supplied to the calculation unit 205 from the intra prediction unit 211 or the motion prediction / compensation unit 212 via the selection unit 213.
- the calculation unit 205 adds the difference image and the prediction image, and obtains a reconstructed image corresponding to the image before the prediction image is subtracted by the calculation unit 103 of the image encoding device 100.
- the arithmetic unit 205 supplies the reconstructed image to the loop filter 206.
- the loop filter 206 appropriately performs a loop filter process including a deblock filter process and an adaptive loop filter process on the supplied reconstructed image to generate a decoded image.
- the loop filter 206 removes block distortion by performing a deblocking filter process on the reconstructed image.
- the loop filter 206 performs image quality improvement by performing loop filter processing using a Wiener filter on the deblock filter processing result (reconstructed image from which block distortion has been removed). I do.
- the type of filter processing performed by the loop filter 206 is arbitrary, and filter processing other than that described above may be performed. Further, the loop filter 206 may perform filter processing using the filter coefficient supplied from the image encoding device 100 of FIG.
- the loop filter 206 supplies the decoded image as the filter processing result to the screen rearrangement buffer 207 and the frame memory 209. Note that the filter processing by the loop filter 206 can be omitted. That is, the output of the calculation unit 205 can be stored in the frame memory 209 without being subjected to filter processing.
- the intra prediction unit 211 uses pixel values of pixels included in this image as pixel values of peripheral pixels.
- the screen rearrangement buffer 207 rearranges the supplied decoded images. That is, the order of frames rearranged for the encoding order by the screen rearrangement buffer 102 in FIG. 1 is rearranged in the original display order.
- the D / A conversion unit 208 D / A converts the decoded image supplied from the screen rearrangement buffer 207, and outputs and displays the decoded image on a display (not shown).
- the frame memory 209 stores supplied reconstructed images and decoded images. Also, the frame memory 209 selects the stored reconstructed image or decoded image from the selection unit 210 at a predetermined timing or based on an external request such as the intra prediction unit 211 or the motion prediction / compensation unit 212. To the intra prediction unit 211 and the motion prediction / compensation unit 212.
- the intra prediction unit 211 performs basically the same processing as the intra prediction unit 114 in FIG. However, the intra prediction unit 211 performs intra prediction only on a region where a prediction image is generated by intra prediction at the time of encoding.
- the motion prediction / compensation unit 212 performs inter prediction (including motion prediction and motion compensation) based on the inter prediction information supplied from the lossless decoding unit 202, and generates a predicted image. Note that the motion prediction / compensation unit 212 performs inter prediction only on a region in which inter prediction has been performed at the time of encoding, based on the inter prediction information supplied from the lossless decoding unit 202.
- the intra prediction unit 211 and the motion prediction / compensation unit 212 supply the generated prediction image to the calculation unit 205 via the selection unit 213 for each region of the prediction processing unit.
- the selection unit 213 supplies the prediction image supplied from the intra prediction unit 211 or the prediction image supplied from the motion prediction / compensation unit 212 to the calculation unit 205.
- the image decoding apparatus 200 further includes a color difference quantization offset setting unit 221.
- chroma_qp_index_offset is set according to the optimum TU size, and the quantization for the color difference signal is performed using the chroma_qp_index_offset Parameters are performed.
- the optimum TU size is the size of the processing unit (orthogonal transform unit) of the actually performed orthogonal transform, and therefore, as the orthogonal transform unit 104 of the image coding device 100 performs, Processing for determining the optimum TU size is omitted.
- the lossless decoding unit 202 acquires the orthogonal transform unit size (optimum TU size) for the combined attention area.
- Information regarding the optimum TU size is arbitrary.
- the syntax as shown in FIG. 6 may be stored in a predetermined position of the encoded data. It may be transmitted separately from the encoded data.
- the lossless decoding unit 202 analyzes the data obtained by decoding, extracts information related to the optimum TU size, and supplies it to the color difference quantization offset setting unit 221.
- the color difference quantization offset setting unit 221 sets chroma_qp_index_offset using the optimum TU size supplied from the lossless decoding unit 202. This process is the same as in the case of the color difference quantization offset setting unit 121. That is, the color difference quantization offset setting unit 221 sets chroma_qp_index_offset so that a smaller value is set for a larger TU.
- the method for obtaining chroma_qp_index_offset from the optimal TU size is arbitrary, but in order to further reduce the error of chroma_qp_index_offset, it is desirable to use the same method as the color difference quantization offset setting unit 121.
- a common method for obtaining chroma_qp_index_offset may be determined in advance for both the image encoding device 100 and the image decoding device 200, or a method for obtaining chroma_qp_index_offset applied in the image encoding device 100
- Information regarding the image encoding apparatus 100 may be transmitted to the image decoding apparatus 200.
- the color difference quantization offset setting unit 221 supplies the set chroma_qp_index_offset to the inverse quantization unit 203.
- the inverse quantization unit 203 uses the chroma_qp_index_offset supplied from the color difference quantization offset setting unit 221 for the color difference signal, obtains a quantization parameter for the color difference signal, and supplies the quantized color difference supplied from the lossless decoding unit 202 Dequantize the orthogonal transform coefficients of the signal.
- FIG. 12 is a block diagram illustrating a main configuration example of the inverse quantization unit 203 in FIG. 11.
- the inverse quantization unit 203 includes a color difference quantization value determination unit 251 and an inverse quantization processing unit 252.
- the color difference quantization value determination unit 251 uses chroma_qp_index_offset and the color difference quantization offset setting unit 221 supplied from the above-described equation (2) and the table shown in FIG. Then, the quantization parameter for the color difference signal is obtained from the quantization parameter for the luminance signal. The color difference quantization value determination unit 251 supplies the quantization parameter for the obtained color difference signal to the inverse quantization processing unit 252.
- the inverse quantization processing unit 252 performs inverse quantization on the quantized orthogonal transform coefficient of the luminance signal supplied from the lossless decoding unit 202 using the quantization parameter for the luminance signal. In addition, the inverse quantization processing unit 252 converts the quantized orthogonal transform coefficient of the color difference signal supplied from the lossless decoding unit 202 and the quantization parameter for the color difference signal supplied from the color difference quantization value determination unit 251. Use inverse quantization.
- the inverse quantization processing unit 252 supplies the orthogonal transform coefficient obtained by the inverse quantization in this way to the inverse orthogonal transform unit 204.
- the inverse orthogonal transform unit 204 performs inverse orthogonal transform on the orthogonal transform coefficient to restore the difference image.
- the inverse quantization unit 203 can correctly inverse-quantize the orthogonal transform coefficient quantized so as to suppress the reduction in the image quality of the color difference signal.
- the image decoding apparatus 200 can correctly decode the encoded data obtained by encoding the image data so as to suppress the reduction in the image quality of the color difference signal due to quantization. Therefore, the image decoding apparatus 200 can realize suppression of a reduction in image quality of the color difference signal due to quantization, and can realize improvement in encoding efficiency of encoded data.
- step S201 the accumulation buffer 201 accumulates the transmitted encoded data.
- step S202 the lossless decoding unit 202 decodes the encoded data supplied from the accumulation buffer 201. That is, the I picture, P picture, and B picture encoded by the lossless encoding unit 106 in FIG. 1 are decoded.
- information such as motion vector information, reference frame information, prediction mode information (intra prediction mode or inter prediction mode), and parameters relating to quantization are also decoded.
- step S203 the color difference quantization offset setting unit 221, the inverse quantization unit 203, and the inverse orthogonal transform unit 204 perform the inverse quantization inverse orthogonal transform process, and the quantized orthogonality obtained by the process of step S202.
- the transform coefficient is inversely quantized, and the obtained orthogonal transform coefficient is further subjected to inverse orthogonal transform.
- step S204 the intra prediction unit 211 or the motion prediction / compensation unit 212 performs image prediction processing corresponding to the prediction mode information supplied from the lossless decoding unit 202, respectively. That is, when intra prediction mode information is supplied from the lossless decoding unit 202, the intra prediction unit 211 performs intra prediction processing in the intra prediction mode. Also, when inter prediction mode information is supplied from the lossless decoding unit 202, the motion prediction / compensation unit 212 performs an inter prediction process (including motion prediction and motion compensation).
- step S205 the calculation unit 205 adds the predicted image obtained by the process of step S204 to the difference information obtained by the process of step S203. As a result, the original image data is decoded.
- step S206 the loop filter 206 appropriately performs a loop filter process including a deblock filter process and an adaptive loop filter process on the reconstructed image obtained by the process in step S205.
- step S207 the screen rearrangement buffer 207 rearranges the frames of the decoded image data. That is, the order of frames of the decoded image data rearranged for encoding by the screen rearrangement buffer 102 (FIG. 1) of the image encoding device 100 is rearranged to the original display order.
- step S208 the D / A converter 208 D / A converts the decoded image data in which the frames are rearranged in the screen rearrangement buffer 207.
- the decoded image data is output to a display (not shown), and the image is displayed.
- step S209 the frame memory 209 stores the decoded image filtered by the process in step S206.
- the color difference quantization offset setting unit 221 selects the optimum TU size extracted by the lossless decoding unit 202 (the encoded data decoded by the lossless decoding unit 202 in step S251). TU size).
- step S252 the color difference quantization offset setting unit 221 determines chroma_qp_index_offset so that a smaller value is set for a larger TU in accordance with the optimum TU size acquired in step S251.
- step S253 the inverse quantization processing unit 252 sets a quantization parameter for the luminance component (luminance signal) of the image.
- step S254 the color difference quantization value determination unit 251 sets a quantization parameter for the color difference component (color difference signal) of the image based on chroma_qp_index_offset determined in step S252.
- step S255 the inverse quantization processing unit 252 uses the quantization parameter for the luminance component set in step S253, and the quantized orthogonal transform coefficient of the luminance signal using the quantization parameter for the luminance signal. Inverse quantization. In addition, the inverse quantization processing unit 252 inversely quantizes the quantized orthogonal transform coefficient of the color difference signal using the quantization parameter for the color difference signal set in step S254.
- step S256 the inverse orthogonal transform unit 204 performs inverse orthogonal transform with the optimal TU size on the orthogonal transform coefficient obtained by the process of step S255.
- the inverse orthogonal transform unit 204 ends the inverse quantization inverse orthogonal transform process, returns the process to step S203 in FIG. 13, and executes the subsequent processes.
- the image decoding apparatus 200 can realize suppression of reduction in image quality of the color difference signal due to quantization. Thereby, the image decoding apparatus 200 can implement
- chroma_qp_index_offset is obtained in each of the image encoding device 100 and the image decoding device 200.
- the present invention is not limited to this, and for example, the encoding side device (image encoding device 100) itself May be transmitted to the decoding side apparatus (image decoding apparatus 200), and the decoding side apparatus (image decoding apparatus 200) may determine the quantization parameter for the color difference signal using the chroma_qp_index_offset. .
- the chroma_qp_index_offset may be added to the encoded data and transmitted.
- the position to which chroma_qp_index_offset is added is arbitrary.
- chroma_qp_index_offset may be transmitted as a predetermined parameter set.
- chroma_qp_index_offset may be collectively transmitted for each predetermined unit.
- chroma_qp_index_offset in a sequence may be stored in a sequence parameter set (SPS (Sequence Parameter Set)).
- SPS Sequence Parameter Set
- chroma_qp_index_offset in a picture may be stored in a picture parameter set (PPS (picture parameter set)).
- chroma_qp_index_offset may be stored in an adaptation parameter set (APS (Adaptation Parameter Set)).
- chroma_qp_index_offset in a slice may be stored in a slice header, a CU header, or the like. Further, chroma_qp_index_offset may be added to positions other than these. Furthermore, information regarding one chroma_qp_index_offset may be added to a plurality of positions of the encoded data.
- chroma_qp_index_offset may be transmitted as data different from the encoded data.
- various parameters used for determining chroma_qp_index_offset of each orthogonal transform unit (TU), such as the above-mentioned correction amount of chroma_qp_index_offset and candidates for chroma_qp_index_offset, are transferred from the encoding side device to the decoding side device. It may be transmitted. Also in this case, the transmission method is the same as in the case of chroma_qp_index_offset described above.
- a rectangular orthogonal transform unit such as 32 ⁇ 2.
- NQT rectangular orthogonal transform unit
- the value of chroma_qp_index_offset of such rectangular orthogonal transform unit (TU) having the same (or approximate) area may be used.
- chroma_qp_index_offset of a 32 ⁇ 2 pixel orthogonal transform unit (TU) may be set to the same value as an 8 ⁇ 8 pixel orthogonal transform unit (TU).
- a value of chroma_qp_index_offset may be newly determined for a rectangular orthogonal transform unit (TU). That is, chroma_qp_index_offset may be set according to the size and shape of the orthogonal transform unit (TU). Further, chroma_qp_index_offset may be set according to the size or shape of the orthogonal transform unit (TU).
- the unit for setting chroma_qp_index_offset is an orthogonal transform unit.
- PU, CU, LCU, unit, or PU unit may be used. Further, it may be a macro block or a sub macro block.
- FIG. 15 shows an example of a multi-view image encoding method.
- the multi-viewpoint image includes a plurality of viewpoint images, and a predetermined one viewpoint image among the plurality of viewpoints is designated as the base view image.
- Each viewpoint image other than the base view image is treated as a non-base view image.
- each view image is encoded / decoded.
- the first embodiment and the second embodiment The method described above in the embodiment may be applied. In this way, for each view, it is possible to suppress a reduction in image quality of the color difference signal due to quantization.
- flags and parameters used in the method described above in the first embodiment and the second embodiment may be shared.
- chroma_qp_index_offset, optimal TU size, quantization parameter for the color difference signal, and the like may be shared in encoding / decoding of each view.
- only some of them may be shared in encoding / decoding of each view, and other necessary information may be shared in encoding / decoding of each view. Good. By doing in this way, the increase in the code amount to transmit can be suppressed and the reduction in encoding efficiency can be suppressed.
- such a parameter may be stored as a parameter common to each view in a predetermined position of the bitstream that can be referred to in the processing of each view, or in the processing of each view.
- the parameter may be referred to.
- FIG. 16 is a diagram illustrating a multi-view image encoding apparatus that performs the above-described multi-view image encoding.
- the multi-view image encoding device 600 includes an encoding unit 601, an encoding unit 602, and a multiplexing unit 603.
- the encoding unit 601 encodes the base view image and generates a base view image encoded stream.
- the encoding unit 602 encodes the non-base view image and generates a non-base view image encoded stream.
- the multiplexing unit 603 multiplexes the base view image encoded stream generated by the encoding unit 601 and the non-base view image encoded stream generated by the encoding unit 602 to generate a multi-view image encoded stream. To do.
- the image encoding device 100 (FIG. 1) can be applied to the encoding unit 601 and the encoding unit 602 of the multi-view image encoding device 600. That is, for example, as described above, the encoding unit 601 and the encoding unit 602 set an offset value (chroma_qp_index_offset) according to the size or shape of the orthogonal transform unit, and use the offset value to determine the color difference signal. A quantization parameter is obtained for, and the color difference signal is quantized using the quantization parameter. Thereby, the multi-view image encoding apparatus 600 (the encoding unit 601 and the encoding unit 602) can suppress the reduction in the image quality of the color difference signal due to the quantization for each view.
- an offset value chroma_qp_index_offset
- the encoding unit 601 and the encoding unit 602 share various parameters related to quantization as described above, an increase in the amount of code to be transmitted can be suppressed, and a reduction in encoding efficiency can be suppressed. be able to.
- FIG. 17 is a diagram illustrating a multi-view image decoding apparatus that performs the above-described multi-view image decoding.
- the multi-view image decoding device 610 includes a demultiplexing unit 611, a decoding unit 612, and a decoding unit 613.
- the demultiplexing unit 611 demultiplexes the multi-view image encoded stream in which the base view image encoded stream and the non-base view image encoded stream are multiplexed, and the base view image encoded stream and the non-base view image The encoded stream is extracted.
- the decoding unit 612 decodes the base view image encoded stream extracted by the demultiplexing unit 611 to obtain a base view image.
- the decoding unit 613 decodes the non-base view image encoded stream extracted by the demultiplexing unit 611 to obtain a non-base view image.
- the image decoding device 200 (FIG. 11) can be applied to the decoding unit 612 and the decoding unit 613 of the multi-view image decoding device 610. That is, for example, as described above, the decoding unit 612 and the decoding unit 613 set an offset value (chroma_qp_index_offset) according to the size or shape of the orthogonal transform unit, and use the offset value to quantize the color difference signal.
- the quantization parameter is obtained, and the color difference signal is inversely quantized using the quantization parameter.
- the multi-viewpoint image decoding apparatus 610 (decoding unit 612 and decoding unit 613) correctly inverse-quantizes the orthogonal transform coefficient quantized so as to suppress the reduction in the image quality of the color difference signal for each view. Can do. That is, the multi-viewpoint image decoding apparatus 610 (decoding unit 612 and decoding unit 613) can suppress a reduction in image quality of the color difference signal due to quantization for each view.
- the decoding unit 612 and the decoding unit 613 share various parameters related to quantization as described above, an increase in the amount of code to be transmitted can be suppressed, and a reduction in encoding efficiency can be suppressed. it can.
- FIG. 18 shows an example of a hierarchical image encoding method.
- the hierarchical image includes a plurality of hierarchical images, and a predetermined one hierarchical image among the plurality of hierarchical layers is designated as the base layer image. Images in each layer other than the base layer image are treated as non-base layer (also called enhancement layer) images.
- an image of each layer is encoded / decoded.
- the first embodiment and the second embodiment are used.
- the method described above may be applied. By doing so, it is possible to suppress a reduction in image quality of the color difference signal due to quantization for each layer.
- the flags and parameters used in the methods described in the first embodiment and the second embodiment may be shared.
- chroma_qp_index_offset, optimal TU size, quantization parameter for the color difference signal, and the like may be shared in encoding / decoding of each layer.
- only some of them may be shared in encoding / decoding of each layer, and other necessary information may be shared in encoding / decoding of each layer. Good. By doing in this way, the increase in the code amount to transmit can be suppressed and the reduction in encoding efficiency can be suppressed.
- a layered image by spatial resolution also referred to as spatial resolution scalability
- spatial scalability spatial resolution
- the resolution of the image is different for each hierarchy.
- the layer of the image with the lowest spatial resolution is defined as a base layer
- the layer of an image with a resolution higher than that of the base layer is defined as a non-base layer (enhancement layer).
- the image data of the non-base layer may be data independent of other layers, and as in the case of the base layer, an image having a resolution of that layer may be obtained only from the image data.
- an image having a resolution of the base layer hierarchy is obtained only from the image data of the base layer.
- an image having a resolution of the non-base layer (enhancement layer) layer is obtained from the image data of the hierarchy and another layer It can be obtained by synthesizing image data (for example, one level below). By doing in this way, the redundancy of the image data between hierarchies can be suppressed.
- the resolution of the encoding / decoding processing unit of each hierarchy is also different from each other. Therefore, in the encoding / decoding of each layer, for example, when sharing parameters related to quantization such as chroma_qp_index_offset, optimal TU size, and quantization parameter for color difference signal, the quantization is performed according to the resolution ratio of each layer. The value of the parameter relating to may be corrected.
- the parameters for providing scalability are not limited to spatial resolution, but include, for example, temporal resolution (temporal scalability).
- temporal resolution temporary scalability
- the frame rate of the image is different for each hierarchy.
- bit depth scalability bit-depth scalability
- chroma scalability chroma scalability
- SNR scalability SNR scalability in which the signal-to-noise ratio (SNR (Signal to Noise ratio)) of the image differs for each layer.
- the parameter values relating to quantization shared between the hierarchies are corrected according to the ratio between the scalable parameter hierarchies. You may do it.
- FIG. 19 is a diagram illustrating a hierarchical image encoding apparatus that performs the above-described hierarchical image encoding.
- the hierarchical image encoding device 620 includes an encoding unit 621, an encoding unit 622, and a multiplexing unit 623.
- the encoding unit 621 encodes the base layer image and generates a base layer image encoded stream.
- the encoding unit 622 encodes the non-base layer image and generates a non-base layer image encoded stream.
- the multiplexing unit 623 multiplexes the base layer image encoded stream generated by the encoding unit 621 and the non-base layer image encoded stream generated by the encoding unit 622 to generate a hierarchical image encoded stream. .
- the image encoding device 100 (FIG. 1) can be applied to the encoding unit 621 and the encoding unit 622 of the hierarchical image encoding device 620. That is, for example, as described above, the encoding unit 621 and the encoding unit 622 set an offset value (chroma_qp_index_offset) according to the size or shape of the orthogonal transform unit, and use the offset value to determine the color difference signal. A quantization parameter is obtained for, and the color difference signal is quantized using the quantization parameter. Accordingly, the hierarchical image encoding device 620 (the encoding unit 621 and the encoding unit 622) can suppress a reduction in image quality of the color difference signal due to quantization for each layer.
- an offset value chroma_qp_index_offset
- the encoding unit 621 and the encoding unit 622 share various parameters related to quantization as described above, an increase in the amount of code to be transmitted can be suppressed, and a reduction in encoding efficiency can be suppressed. be able to.
- FIG. 20 is a diagram illustrating a hierarchical image decoding apparatus that performs the hierarchical image decoding described above.
- the hierarchical image decoding device 630 includes a demultiplexing unit 631, a decoding unit 632, and a decoding unit 633.
- the demultiplexing unit 631 demultiplexes the hierarchical image encoded stream in which the base layer image encoded stream and the non-base layer image encoded stream are multiplexed, and the base layer image encoded stream and the non-base layer image code Stream.
- the decoding unit 632 decodes the base layer image encoded stream extracted by the demultiplexing unit 631 to obtain a base layer image.
- the decoding unit 633 decodes the non-base layer image encoded stream extracted by the demultiplexing unit 631 to obtain a non-base layer image.
- the image decoding device 200 (FIG. 11) can be applied to the decoding unit 632 and the decoding unit 633 of the hierarchical image decoding device 630. That is, for example, as described above, the decoding unit 632 and the decoding unit 633 set an offset value (chroma_qp_index_offset) according to the size or shape of the orthogonal transform unit, and use the offset value to quantize the color difference signal.
- the quantization parameter is obtained, and the color difference signal is inversely quantized using the quantization parameter.
- the hierarchical image decoding device 630 (decoding unit 632 and decoding unit 633) can correctly inverse-quantize the orthogonal transform coefficient quantized so as to suppress the reduction in the image quality of the color difference signal for each layer. it can. That is, the hierarchical image decoding device 630 (decoding unit 632 and decoding unit 633) can suppress a reduction in image quality of the color difference signal due to quantization for each layer.
- the decoding unit 632 and the decoding unit 633 share various parameters related to quantization as described above, thereby suppressing an increase in the amount of code to be transmitted and suppressing a decrease in encoding efficiency. it can.
- a CPU (Central Processing Unit) 801 of a computer 800 has various programs according to a program stored in a ROM (Read Only Memory) 802 or a program loaded from a storage unit 813 to a RAM (Random Access Memory) 803. Execute the process.
- the RAM 803 also appropriately stores data necessary for the CPU 801 to execute various processes.
- the CPU 801, the ROM 802, and the RAM 803 are connected to each other via a bus 804.
- An input / output interface 810 is also connected to the bus 804.
- the input / output interface 810 includes an input unit 811 including a keyboard, a mouse, a touch panel, and an input terminal, a display including a CRT (Cathode Ray Tube), an LCD (Liquid Crystal Display), an OELD (Organic ElectroLuminescence Display), and the like.
- An output unit 812 including an arbitrary output device such as a speaker, an output terminal, and the like; a storage unit 813 configured by an arbitrary storage medium such as a hard disk and a flash memory; a control unit that controls input and output of the storage medium; a modem;
- a communication unit 814 including a wired or wireless communication device such as a LAN interface, USB (Universal Serial Bus), and Bluetooth (registered trademark) is connected.
- the communication unit 814 performs communication processing with other communication devices via a network including the Internet, for example.
- a drive 815 is connected to the input / output interface 810 as necessary.
- a removable medium 821 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory is appropriately attached to the drive 815.
- the drive 815 reads out a computer program, data, and the like from the removable medium 821 attached to the drive 815 according to the control of the CPU 801, for example.
- the read data and computer program are supplied to the RAM 803, for example.
- the computer program read from the removable medium 821 is installed in the storage unit 813 as necessary.
- a program constituting the software is installed from a network or a recording medium.
- the recording medium is distributed to distribute the program to the user separately from the apparatus main body, and includes a magnetic disk (including a flexible disk) on which the program is recorded, an optical disk ( It only consists of removable media 821 consisting of CD-ROM (including Compact Disc-Read Only Memory), DVD (including Digital Versatile Disc), magneto-optical disk (including MD (Mini Disc)), or semiconductor memory. Rather, it is composed of a ROM 802 on which a program is recorded and a hard disk included in the storage unit 813, which is distributed to the user in a state of being incorporated in the apparatus main body in advance.
- a magnetic disk including a flexible disk
- an optical disk It only consists of removable media 821 consisting of CD-ROM (including Compact Disc-Read Only Memory), DVD (including Digital Versatile Disc), magneto-optical disk (including MD (Mini Disc)), or semiconductor memory. Rather, it is composed of a ROM 802 on which a program is recorded and a hard disk included in the storage unit
- the program executed by the computer may be a program that is processed in time series in the order described in this specification, or in parallel or at a necessary timing such as when a call is made. It may be a program for processing.
- the step of describing the program recorded on the recording medium is not limited to the processing performed in chronological order according to the described order, but may be performed in parallel or It also includes processes that are executed individually.
- system represents the entire apparatus composed of a plurality of devices (apparatuses).
- the configuration described as one device (or processing unit) may be divided and configured as a plurality of devices (or processing units).
- the configurations described above as a plurality of devices (or processing units) may be combined into a single device (or processing unit).
- a configuration other than that described above may be added to the configuration of each device (or each processing unit).
- a part of the configuration of a certain device (or processing unit) may be included in the configuration of another device (or other processing unit).
- the image encoding apparatus 100 (FIG. 1) and the image decoding apparatus 200 (FIG. 11) are distributed to satellite broadcasting, cable broadcasting such as cable TV, distribution on the Internet, and terminals by cellular communication.
- the present invention can be applied to various electronic devices such as a recording device that records an image on a medium such as a transmitter or receiver, an optical disk, a magnetic disk, and a flash memory, or a reproducing device that reproduces an image from these storage media.
- a recording device that records an image on a medium such as a transmitter or receiver
- an optical disk a magnetic disk
- a flash memory or a reproducing device that reproduces an image from these storage media.
- FIG. 22 shows an example of a schematic configuration of a television apparatus to which the above-described embodiment is applied.
- the television apparatus 900 includes an antenna 901, a tuner 902, a demultiplexer 903, a decoder 904, a video signal processing unit 905, a display unit 906, an audio signal processing unit 907, a speaker 908, an external interface 909, a control unit 910, a user interface 911, And a bus 912.
- Tuner 902 extracts a signal of a desired channel from a broadcast signal received via antenna 901, and demodulates the extracted signal. Then, the tuner 902 outputs the encoded bit stream obtained by the demodulation to the demultiplexer 903. That is, the tuner 902 has a role as a transmission unit in the television device 900 that receives an encoded stream in which an image is encoded.
- the demultiplexer 903 separates the video stream and audio stream of the viewing target program from the encoded bit stream, and outputs each separated stream to the decoder 904. Further, the demultiplexer 903 extracts auxiliary data such as EPG (Electronic Program Guide) from the encoded bit stream, and supplies the extracted data to the control unit 910. Note that the demultiplexer 903 may perform descrambling when the encoded bit stream is scrambled.
- EPG Electronic Program Guide
- the decoder 904 decodes the video stream and audio stream input from the demultiplexer 903. Then, the decoder 904 outputs the video data generated by the decoding process to the video signal processing unit 905. In addition, the decoder 904 outputs audio data generated by the decoding process to the audio signal processing unit 907.
- the video signal processing unit 905 reproduces the video data input from the decoder 904 and causes the display unit 906 to display the video.
- the video signal processing unit 905 may cause the display unit 906 to display an application screen supplied via a network.
- the video signal processing unit 905 may perform additional processing such as noise removal on the video data according to the setting.
- the video signal processing unit 905 may generate a GUI (Graphical User Interface) image such as a menu, a button, or a cursor, and superimpose the generated image on the output image.
- GUI Graphic User Interface
- the display unit 906 is driven by a drive signal supplied from the video signal processing unit 905, and displays an image on a video screen of a display device (for example, a liquid crystal display, a plasma display, or an OELD (Organic ElectroLuminescence Display) (organic EL display)). Or an image is displayed.
- a display device for example, a liquid crystal display, a plasma display, or an OELD (Organic ElectroLuminescence Display) (organic EL display)). Or an image is displayed.
- the audio signal processing unit 907 performs reproduction processing such as D / A conversion and amplification on the audio data input from the decoder 904, and outputs audio from the speaker 908.
- the audio signal processing unit 907 may perform additional processing such as noise removal on the audio data.
- the external interface 909 is an interface for connecting the television apparatus 900 to an external device or a network.
- a video stream or an audio stream received via the external interface 909 may be decoded by the decoder 904. That is, the external interface 909 also has a role as a transmission unit in the television apparatus 900 that receives an encoded stream in which an image is encoded.
- the control unit 910 includes a processor such as a CPU and memories such as a RAM and a ROM.
- the memory stores a program executed by the CPU, program data, EPG data, data acquired via a network, and the like.
- the program stored in the memory is read and executed by the CPU when the television apparatus 900 is activated.
- the CPU executes the program to control the operation of the television device 900 according to an operation signal input from the user interface 911, for example.
- the user interface 911 is connected to the control unit 910.
- the user interface 911 includes, for example, buttons and switches for the user to operate the television device 900, a remote control signal receiving unit, and the like.
- the user interface 911 detects an operation by the user via these components, generates an operation signal, and outputs the generated operation signal to the control unit 910.
- the bus 912 connects the tuner 902, the demultiplexer 903, the decoder 904, the video signal processing unit 905, the audio signal processing unit 907, the external interface 909, and the control unit 910 to each other.
- the decoder 904 has the function of the image decoding apparatus 200 (FIG. 11) according to the above-described embodiment. Therefore, the decoder 904 can obtain the quantization parameter for the color difference signal using the offset value for the quantization parameter for the luminance signal, which is controlled according to the size of the processing unit such as orthogonal transform. Therefore, the television apparatus 900 can realize suppression of a reduction in image quality of the color difference signal due to quantization.
- FIG. 23 shows an example of a schematic configuration of a mobile phone to which the above-described embodiment is applied.
- a mobile phone 920 includes an antenna 921, a communication unit 922, an audio codec 923, a speaker 924, a microphone 925, a camera unit 926, an image processing unit 927, a demultiplexing unit 928, a recording / reproducing unit 929, a display unit 930, a control unit 931, an operation A portion 932 and a bus 933.
- the antenna 921 is connected to the communication unit 922.
- the speaker 924 and the microphone 925 are connected to the audio codec 923.
- the operation unit 932 is connected to the control unit 931.
- the bus 933 connects the communication unit 922, the audio codec 923, the camera unit 926, the image processing unit 927, the demultiplexing unit 928, the recording / reproducing unit 929, the display unit 930, and the control unit 931 to each other.
- the mobile phone 920 has various operation modes including a voice call mode, a data communication mode, a shooting mode, and a videophone mode, and is used for sending and receiving voice signals, sending and receiving e-mail or image data, taking images, and recording data. Perform the action.
- the analog voice signal generated by the microphone 925 is supplied to the voice codec 923.
- the audio codec 923 converts an analog audio signal into audio data, A / D converts the compressed audio data, and compresses it. Then, the audio codec 923 outputs the compressed audio data to the communication unit 922.
- the communication unit 922 encodes and modulates the audio data and generates a transmission signal. Then, the communication unit 922 transmits the generated transmission signal to a base station (not shown) via the antenna 921. In addition, the communication unit 922 amplifies a radio signal received via the antenna 921 and performs frequency conversion to acquire a received signal.
- the communication unit 922 demodulates and decodes the received signal to generate audio data, and outputs the generated audio data to the audio codec 923.
- the audio codec 923 decompresses the audio data and performs D / A conversion to generate an analog audio signal. Then, the audio codec 923 supplies the generated audio signal to the speaker 924 to output audio.
- the control unit 931 generates character data constituting the e-mail in response to an operation by the user via the operation unit 932.
- the control unit 931 causes the display unit 930 to display characters.
- the control unit 931 generates e-mail data in response to a transmission instruction from the user via the operation unit 932, and outputs the generated e-mail data to the communication unit 922.
- the communication unit 922 encodes and modulates email data and generates a transmission signal. Then, the communication unit 922 transmits the generated transmission signal to a base station (not shown) via the antenna 921.
- the communication unit 922 amplifies a radio signal received via the antenna 921 and performs frequency conversion to acquire a received signal.
- the communication unit 922 demodulates and decodes the received signal to restore the email data, and outputs the restored email data to the control unit 931.
- the control unit 931 displays the content of the electronic mail on the display unit 930 and stores the electronic mail data in the storage medium of the recording / reproducing unit 929.
- the recording / reproducing unit 929 has an arbitrary readable / writable storage medium.
- the storage medium may be a built-in storage medium such as a RAM or a flash memory, or an externally mounted storage medium such as a hard disk, a magnetic disk, a magneto-optical disk, an optical disk, a USB memory, or a memory card. May be.
- the camera unit 926 images a subject to generate image data, and outputs the generated image data to the image processing unit 927.
- the image processing unit 927 encodes the image data input from the camera unit 926 and stores the encoded stream in the storage medium of the recording / playback unit 929.
- the demultiplexing unit 928 multiplexes the video stream encoded by the image processing unit 927 and the audio stream input from the audio codec 923, and the multiplexed stream is the communication unit 922. Output to.
- the communication unit 922 encodes and modulates the stream and generates a transmission signal. Then, the communication unit 922 transmits the generated transmission signal to a base station (not shown) via the antenna 921.
- the communication unit 922 amplifies a radio signal received via the antenna 921 and performs frequency conversion to acquire a received signal.
- These transmission signal and reception signal may include an encoded bit stream.
- the communication unit 922 demodulates and decodes the received signal to restore the stream, and outputs the restored stream to the demultiplexing unit 928.
- the demultiplexing unit 928 separates the video stream and the audio stream from the input stream, and outputs the video stream to the image processing unit 927 and the audio stream to the audio codec 923.
- the image processing unit 927 decodes the video stream and generates video data.
- the video data is supplied to the display unit 930, and a series of images is displayed on the display unit 930.
- the audio codec 923 decompresses the audio stream and performs D / A conversion to generate an analog audio signal. Then, the audio codec 923 supplies the generated audio signal to the speaker 924 to output audio.
- the image processing unit 927 has the function of the image encoding device 100 (FIG. 1) and the function of the image decoding device 200 (FIG. 11) according to the above-described embodiment. Accordingly, for an image encoded and decoded by the mobile phone 920, the image processing unit 927 offsets the quantization parameter for the color difference signal with respect to the quantization parameter for the luminance signal according to the size of the processing unit such as orthogonal transform. It is possible to control the value or obtain the quantization parameter for the color difference signal from the quantization parameter for the luminance signal by using the offset value. Therefore, the mobile phone 920 can suppress a reduction in image quality of the color difference signal due to quantization.
- the mobile phone 920 has been described.
- an imaging function similar to that of the mobile phone 920 such as a PDA (Personal Digital Assistant), a smartphone, an UMPC (Ultra Mobile Personal Computer), a netbook, a notebook personal computer, or the like.
- the image encoding device and the image decoding device to which the present technology is applied can be applied to any device as in the case of the mobile phone 920.
- FIG. 24 shows an example of a schematic configuration of a recording / reproducing apparatus to which the above-described embodiment is applied.
- the recording / reproducing device 940 encodes audio data and video data of a received broadcast program and records the encoded data on a recording medium.
- the recording / reproducing device 940 may encode audio data and video data acquired from another device and record them on a recording medium, for example.
- the recording / reproducing device 940 reproduces data recorded on the recording medium on a monitor and a speaker, for example, in accordance with a user instruction. At this time, the recording / reproducing device 940 decodes the audio data and the video data.
- the recording / reproducing apparatus 940 includes a tuner 941, an external interface 942, an encoder 943, an HDD (Hard Disk Drive) 944, a disk drive 945, a selector 946, a decoder 947, an OSD (On-Screen Display) 948, a control unit 949, and a user interface. 950.
- Tuner 941 extracts a signal of a desired channel from a broadcast signal received via an antenna (not shown), and demodulates the extracted signal. Then, the tuner 941 outputs the encoded bit stream obtained by the demodulation to the selector 946. That is, the tuner 941 serves as a transmission unit in the recording / reproducing apparatus 940.
- the external interface 942 is an interface for connecting the recording / reproducing apparatus 940 to an external device or a network.
- the external interface 942 may be, for example, an IEEE1394 interface, a network interface, a USB interface, or a flash memory interface.
- video data and audio data received via the external interface 942 are input to the encoder 943. That is, the external interface 942 serves as a transmission unit in the recording / reproducing device 940.
- the encoder 943 encodes video data and audio data when the video data and audio data input from the external interface 942 are not encoded. Then, the encoder 943 outputs the encoded bit stream to the selector 946.
- the HDD 944 records an encoded bit stream in which content data such as video and audio is compressed, various programs, and other data on an internal hard disk. Further, the HDD 944 reads out these data from the hard disk when reproducing video and audio.
- the disk drive 945 performs recording and reading of data to and from the mounted recording medium.
- the recording medium mounted on the disk drive 945 is, for example, a DVD disk (DVD-Video, DVD-RAM, DVD-R, DVD-RW, DVD + R, DVD + RW, etc.) or a Blu-ray (registered trademark) disk. It may be.
- the selector 946 selects an encoded bit stream input from the tuner 941 or the encoder 943 when recording video and audio, and outputs the selected encoded bit stream to the HDD 944 or the disk drive 945. In addition, the selector 946 outputs the encoded bit stream input from the HDD 944 or the disk drive 945 to the decoder 947 during video and audio reproduction.
- the decoder 947 decodes the encoded bit stream and generates video data and audio data. Then, the decoder 947 outputs the generated video data to the OSD 948. The decoder 904 outputs the generated audio data to an external speaker.
- OSD 948 reproduces the video data input from the decoder 947 and displays the video. Further, the OSD 948 may superimpose a GUI image such as a menu, a button, or a cursor on the video to be displayed.
- the control unit 949 includes a processor such as a CPU and memories such as a RAM and a ROM.
- the memory stores a program executed by the CPU, program data, and the like.
- the program stored in the memory is read and executed by the CPU when the recording / reproducing apparatus 940 is activated, for example.
- the CPU controls the operation of the recording / reproducing apparatus 940 in accordance with an operation signal input from the user interface 950, for example, by executing the program.
- the user interface 950 is connected to the control unit 949.
- the user interface 950 includes, for example, buttons and switches for the user to operate the recording / reproducing device 940, a remote control signal receiving unit, and the like.
- the user interface 950 detects an operation by the user via these components, generates an operation signal, and outputs the generated operation signal to the control unit 949.
- the encoder 943 has the function of the image encoding apparatus 100 (FIG. 1) according to the above-described embodiment.
- the decoder 947 has the function of the image decoding device 200 (FIG. 11) according to the above-described embodiment. Therefore, for an image encoded and decoded by the recording / reproducing device 940, the encoder 943 and the decoder 947 have the quantization parameter for the color difference signal and the quantization parameter for the luminance signal according to the size of the processing unit such as orthogonal transform.
- the offset value for the color difference signal can be controlled, or the offset value can be used to obtain the quantization parameter for the color difference signal from the quantization parameter for the luminance signal. Therefore, the recording / reproducing apparatus 940 can suppress a reduction in image quality of the color difference signal due to quantization.
- FIG. 25 illustrates an example of a schematic configuration of an imaging apparatus to which the above-described embodiment is applied.
- the imaging device 960 images a subject to generate an image, encodes the image data, and records it on a recording medium.
- the imaging device 960 includes an optical block 961, an imaging unit 962, a signal processing unit 963, an image processing unit 964, a display unit 965, an external interface 966, a memory 967, a media drive 968, an OSD 969, a control unit 970, a user interface 971, and a bus. 972.
- the optical block 961 is connected to the imaging unit 962.
- the imaging unit 962 is connected to the signal processing unit 963.
- the display unit 965 is connected to the image processing unit 964.
- the user interface 971 is connected to the control unit 970.
- the bus 972 connects the image processing unit 964, the external interface 966, the memory 967, the media drive 968, the OSD 969, and the control unit 970 to each other.
- the optical block 961 includes a focus lens and a diaphragm mechanism.
- the optical block 961 forms an optical image of the subject on the imaging surface of the imaging unit 962.
- the imaging unit 962 includes an image sensor such as a CCD or a CMOS, and converts an optical image formed on the imaging surface into an image signal as an electrical signal by photoelectric conversion. Then, the imaging unit 962 outputs the image signal to the signal processing unit 963.
- the signal processing unit 963 performs various camera signal processing such as knee correction, gamma correction, and color correction on the image signal input from the imaging unit 962.
- the signal processing unit 963 outputs the image data after the camera signal processing to the image processing unit 964.
- the image processing unit 964 encodes the image data input from the signal processing unit 963 and generates encoded data. Then, the image processing unit 964 outputs the generated encoded data to the external interface 966 or the media drive 968. The image processing unit 964 also decodes encoded data input from the external interface 966 or the media drive 968 to generate image data. Then, the image processing unit 964 outputs the generated image data to the display unit 965. In addition, the image processing unit 964 may display the image by outputting the image data input from the signal processing unit 963 to the display unit 965. Further, the image processing unit 964 may superimpose display data acquired from the OSD 969 on an image output to the display unit 965.
- the OSD 969 generates a GUI image such as a menu, a button, or a cursor, and outputs the generated image to the image processing unit 964.
- the external interface 966 is configured as a USB input / output terminal, for example.
- the external interface 966 connects the imaging device 960 and a printer, for example, when printing an image.
- a drive is connected to the external interface 966 as necessary.
- a removable medium such as a magnetic disk or an optical disk is attached to the drive, and a program read from the removable medium can be installed in the imaging device 960.
- the external interface 966 may be configured as a network interface connected to a network such as a LAN or the Internet. That is, the external interface 966 has a role as a transmission unit in the imaging device 960.
- the recording medium mounted on the media drive 968 may be any readable / writable removable medium such as a magnetic disk, a magneto-optical disk, an optical disk, or a semiconductor memory.
- a recording medium may be fixedly mounted on the media drive 968, and a non-portable storage unit such as an internal hard disk drive or an SSD (Solid State Drive) may be configured.
- the control unit 970 includes a processor such as a CPU and memories such as a RAM and a ROM.
- the memory stores a program executed by the CPU, program data, and the like.
- the program stored in the memory is read and executed by the CPU when the imaging device 960 is activated, for example.
- the CPU controls the operation of the imaging device 960 according to an operation signal input from the user interface 971 by executing the program.
- the user interface 971 is connected to the control unit 970.
- the user interface 971 includes, for example, buttons and switches for the user to operate the imaging device 960.
- the user interface 971 detects an operation by the user via these components, generates an operation signal, and outputs the generated operation signal to the control unit 970.
- the image processing unit 964 has the functions of the image encoding apparatus 100 (FIG. 1) and the image decoding apparatus 200 (FIG. 11) according to the above-described embodiment. Accordingly, for an image encoded and decoded by the imaging device 960, the image processing unit 964 offsets the quantization parameter for the color difference signal with respect to the quantization parameter for the luminance signal according to the size of the processing unit such as orthogonal transformation. It is possible to control the value or obtain the quantization parameter for the color difference signal from the quantization parameter for the luminance signal by using the offset value. Therefore, the imaging device 960 can suppress a reduction in image quality of the color difference signal due to quantization.
- the image encoding device and the image decoding device to which the present technology is applied can be applied to devices and systems other than the above-described devices.
- Scalable encoding is used for selection of data to be transmitted, for example, as in the example shown in FIG.
- the distribution server 1002 reads the scalable encoded data stored in the scalable encoded data storage unit 1001, and via the network 1003, the personal computer 1004, the AV device 1005, the tablet This is distributed to the terminal device such as the device 1006 and the mobile phone 1007.
- the distribution server 1002 selects and transmits encoded data of appropriate quality according to the capability of the terminal device, the communication environment, and the like. Even if the distribution server 1002 transmits high-quality data unnecessarily, a high-quality image is not always obtained in the terminal device, which may cause a delay or an overflow. Moreover, there is a possibility that the communication band is unnecessarily occupied or the load on the terminal device is unnecessarily increased. On the other hand, even if the distribution server 1002 transmits unnecessarily low quality data, there is a possibility that an image with sufficient image quality cannot be obtained in the terminal device. Therefore, the distribution server 1002 appropriately reads and transmits the scalable encoded data stored in the scalable encoded data storage unit 1001 as encoded data having an appropriate quality with respect to the capability and communication environment of the terminal device. .
- the scalable encoded data storage unit 1001 stores scalable encoded data (BL + EL) 1011 encoded in a scalable manner.
- the scalable encoded data (BL + EL) 1011 is encoded data including both a base layer and an enhancement layer, and is a data that can be decoded to obtain both a base layer image and an enhancement layer image. It is.
- the distribution server 1002 selects an appropriate layer according to the capability of the terminal device that transmits data, the communication environment, and the like, and reads the data of the layer. For example, the distribution server 1002 reads high-quality scalable encoded data (BL + EL) 1011 from the scalable encoded data storage unit 1001 and transmits it to the personal computer 1004 and the tablet device 1006 with high processing capability as they are. . On the other hand, for example, the distribution server 1002 extracts base layer data from the scalable encoded data (BL + EL) 1011 for the AV device 1005 and the cellular phone 1007 having a low processing capability, and performs scalable encoding. Although it is data of the same content as the data (BL + EL) 1011, it is transmitted as scalable encoded data (BL) 1012 having a lower quality than the scalable encoded data (BL + EL) 1011.
- BL scalable encoded data
- scalable encoded data By using scalable encoded data in this way, the amount of data can be easily adjusted, so that the occurrence of delays and overflows can be suppressed, and unnecessary increases in the load on terminal devices and communication media can be suppressed. be able to.
- scalable encoded data (BL + EL) 1011 since scalable encoded data (BL + EL) 1011 has reduced redundancy between layers, the amount of data can be reduced as compared with the case where encoded data of each layer is used as individual data. . Therefore, the storage area of the scalable encoded data storage unit 1001 can be used more efficiently.
- the hardware performance of the terminal device varies depending on the device.
- the application which a terminal device performs is also various, the capability of the software is also various.
- the network 1003 serving as a communication medium can be applied to any communication network including wired, wireless, or both, such as the Internet and a LAN (Local Area Network), and has various data transmission capabilities. Furthermore, there is a risk of change due to other communications.
- the distribution server 1002 communicates with the terminal device that is the data transmission destination before starting data transmission, and the hardware performance of the terminal device, the performance of the application (software) executed by the terminal device, etc. Information regarding the capability of the terminal device and information regarding the communication environment such as the available bandwidth of the network 1003 may be obtained. The distribution server 1002 may select an appropriate layer based on the information obtained here.
- the layer extraction may be performed by the terminal device.
- the personal computer 1004 may decode the transmitted scalable encoded data (BL + EL) 1011 and display a base layer image or an enhancement layer image. Further, for example, the personal computer 1004 extracts the base layer scalable encoded data (BL) 1012 from the transmitted scalable encoded data (BL + EL) 1011 and stores it or transfers it to another device. The base layer image may be displayed after decoding.
- the numbers of the scalable encoded data storage unit 1001, the distribution server 1002, the network 1003, and the terminal devices are arbitrary.
- the example in which the distribution server 1002 transmits data to the terminal device has been described, but the usage example is not limited to this.
- the data transmission system 1000 may be any system as long as it transmits a scalable encoded data to a terminal device by selecting an appropriate layer according to the capability of the terminal device or a communication environment. Can be applied to the system.
- the present technology is applied in the same manner as the application to the hierarchical encoding / decoding described above with reference to FIGS. Effects similar to those described above with reference to FIGS. 18 to 20 can be obtained.
- scalable coding is used for transmission via a plurality of communication media, for example, as in the example shown in FIG.
- a broadcasting station 1101 transmits base layer scalable encoded data (BL) 1121 by terrestrial broadcasting 1111. Also, the broadcast station 1101 transmits enhancement layer scalable encoded data (EL) 1122 via an arbitrary network 1112 including a wired or wireless communication network or both (for example, packetized transmission).
- BL base layer scalable encoded data
- EL enhancement layer scalable encoded data
- the terminal apparatus 1102 has a reception function of the terrestrial broadcast 1111 broadcast by the broadcast station 1101 and receives base layer scalable encoded data (BL) 1121 transmitted via the terrestrial broadcast 1111.
- the terminal apparatus 1102 further has a communication function for performing communication via the network 1112, and receives enhancement layer scalable encoded data (EL) 1122 transmitted via the network 1112.
- BL base layer scalable encoded data
- EL enhancement layer scalable encoded data
- the terminal device 1102 decodes the base layer scalable encoded data (BL) 1121 acquired via the terrestrial broadcast 1111 according to, for example, a user instruction, and obtains or stores a base layer image. Or transmit to other devices.
- BL base layer scalable encoded data
- the terminal device 1102 for example, in response to a user instruction, the base layer scalable encoded data (BL) 1121 acquired via the terrestrial broadcast 1111 and the enhancement layer scalable encoded acquired via the network 1112 Data (EL) 1122 is combined to obtain scalable encoded data (BL + EL), or decoded to obtain an enhancement layer image, stored, or transmitted to another device.
- BL base layer scalable encoded data
- EL enhancement layer scalable encoded acquired via the network 1112 Data
- the scalable encoded data can be transmitted via a communication medium that is different for each layer, for example. Therefore, the load can be distributed, and the occurrence of delay and overflow can be suppressed.
- the communication medium used for transmission may be selected for each layer. For example, scalable encoded data (BL) 1121 of a base layer having a relatively large amount of data is transmitted via a communication medium having a wide bandwidth, and scalable encoded data (EL) 1122 having a relatively small amount of data is transmitted. You may make it transmit via a communication medium with a narrow bandwidth. Further, for example, the communication medium for transmitting the enhancement layer scalable encoded data (EL) 1122 is switched between the network 1112 and the terrestrial broadcast 1111 according to the available bandwidth of the network 1112. May be. Of course, the same applies to data of an arbitrary layer.
- the number of layers is arbitrary, and the number of communication media used for transmission is also arbitrary.
- the number of terminal devices 1102 serving as data distribution destinations is also arbitrary.
- broadcasting from the broadcasting station 1101 has been described as an example, but the usage example is not limited to this.
- the data transmission system 1100 can be applied to any system as long as it is a system that divides scalable encoded data into a plurality of layers and transmits them through a plurality of lines.
- the present technology is applied in the same manner as the application to the hierarchical encoding / decoding described above with reference to FIGS.
- the same effect as described above with reference to FIG. 20 can be obtained.
- scalable coding is used for storing coded data, for example, as in the example shown in FIG.
- the imaging device 1201 performs scalable coding on image data obtained by imaging the subject 1211, and as scalable coded data (BL + EL) 1221, a scalable coded data storage device 1202. To supply.
- the scalable encoded data storage device 1202 stores the scalable encoded data (BL + EL) 1221 supplied from the imaging device 1201 with quality according to the situation. For example, in the normal case, the scalable encoded data storage device 1202 extracts base layer data from the scalable encoded data (BL + EL) 1221, and the base layer scalable encoded data ( BL) 1222. On the other hand, for example, in the case of attention, the scalable encoded data storage device 1202 stores scalable encoded data (BL + EL) 1221 with high quality and a large amount of data.
- the scalable encoded data storage device 1202 can store an image with high image quality only when necessary, so that an increase in the amount of data can be achieved while suppressing a reduction in the value of the image due to image quality degradation. And the use efficiency of the storage area can be improved.
- the imaging device 1201 is a surveillance camera.
- the monitoring target for example, an intruder
- the content of the captured image is likely to be unimportant. Data
- the image quality is given priority and the image data (scalable) (Encoded data) is stored with high quality.
- whether it is normal time or attention time may be determined by the scalable encoded data storage device 1202 analyzing an image, for example.
- the imaging apparatus 1201 may make a determination, and the determination result may be transmitted to the scalable encoded data storage device 1202.
- the criterion for determining whether the time is normal or noting is arbitrary, and the content of the image as the criterion is arbitrary. Of course, conditions other than the contents of the image can also be used as the criterion. For example, it may be switched according to the volume or waveform of the recorded sound, may be switched at every predetermined time, or may be switched by an external instruction such as a user instruction.
- the number of states is arbitrary, for example, normal, slightly attention, attention, very attention, etc.
- three or more states may be switched.
- the upper limit number of states to be switched depends on the number of layers of scalable encoded data.
- the imaging apparatus 1201 may determine the number of scalable coding layers according to the state. For example, in a normal case, the imaging apparatus 1201 may generate base layer scalable encoded data (BL) 1222 with low quality and a small amount of data, and supply the scalable encoded data storage apparatus 1202 to the scalable encoded data storage apparatus 1202. Further, for example, when attention is paid, the imaging device 1201 generates scalable encoded data (BL + EL) 1221 having a high quality and a large amount of data, and supplies the scalable encoded data storage device 1202 to the scalable encoded data storage device 1202. May be.
- BL base layer scalable encoded data
- BL + EL scalable encoded data
- the monitoring camera has been described as an example.
- the use of the imaging system 1200 is arbitrary and is not limited to the monitoring camera.
- the present technology is applied in the same manner as the application to the hierarchical encoding / decoding described above with reference to FIGS.
- the effect similar to the effect mentioned above with reference to 20 can be acquired.
- the present technology can also be applied to HTTP streaming such as MPEGASHDASH, for example, by selecting an appropriate piece of data from a plurality of encoded data with different resolutions prepared in advance. Can do. That is, information regarding encoding and decoding can be shared among a plurality of such encoded data.
- the term “associate” means that an image (which may be a part of an image such as a slice or a block) included in the bitstream and information corresponding to the image can be linked at the time of decoding. Means. That is, information may be transmitted on a transmission path different from that of the image (or bit stream). Information may be recorded on a recording medium (or another recording area of the same recording medium) different from the image (or bit stream). Furthermore, the information and the image (or bit stream) may be associated with each other in an arbitrary unit such as a plurality of frames, one frame, or a part of the frame.
- this technique can also take the following structures.
- an offset setting unit that sets an offset of a quantization parameter for a chrominance signal based on a quantization parameter for a luminance signal according to the size or shape of a transform unit when orthogonally transforming image data;
- a quantization unit that quantizes an orthogonal transform coefficient of the image data using a quantization parameter for the color difference signal obtained from a quantization parameter for the luminance signal using the offset set by the offset setting unit.
- An image processing apparatus comprising: (2) The image processing apparatus according to (1), wherein the offset setting unit sets the offset so that quantization is performed by a finer quantization step with respect to the larger transform unit.
- the offset setting unit sets the offset of the larger conversion unit to a smaller value.
- the offset setting unit performs quantization by a finer quantization step for an orthogonal transform coefficient having a size that is more easily referred to according to a bit rate of encoded data obtained by encoding the image data.
- the offset setting unit sets the value of the offset for a square conversion unit having the same or approximate size as the conversion unit, as the offset for the rectangular conversion unit.
- (1) to (5) An image processing apparatus according to any one of the above. (7) The image processing according to any one of (1) to (5), wherein the offset setting unit sets the offset according to a size and shape of a transform unit when orthogonally transforming the image data. apparatus. (8) An image processing method for an image processing apparatus, The offset setting unit sets the quantization parameter offset for the color difference signal based on the quantization parameter for the luminance signal according to the size or shape of the transform unit when orthogonally transforming the image data, An image processing method in which a quantization unit quantizes an orthogonal transform coefficient of the image data using a quantization parameter for the color difference signal obtained from a quantization parameter for the luminance signal using the set offset .
- an offset setting unit that sets an offset of the quantization parameter for the color difference signal based on the quantization parameter for the luminance signal according to the size or shape of the transform unit when orthogonally transforming the image data;
- the quantized orthogonal transform coefficient of the image data is inversely quantized using the quantization parameter for the color difference signal obtained from the quantization parameter for the luminance signal using the offset set by the offset setting unit.
- An image processing apparatus comprising: (10) An image processing method for an image processing apparatus,
- the offset setting unit sets the quantization parameter offset for the color difference signal based on the quantization parameter for the luminance signal according to the size or shape of the transform unit when orthogonally transforming the image data,
- An inverse quantization unit reverses a quantized orthogonal transform coefficient of the image data using a quantization parameter for the color difference signal obtained from a quantization parameter for the luminance signal using the set offset.
- Image processing method to quantize to quantize.
- an offset setting unit that sets an offset of a quantization parameter for a color difference signal based on a quantization parameter for a luminance signal according to the size or shape of a transform unit when orthogonally transforming image data;
- An encoding unit for encoding the image data;
- An image processing apparatus comprising: a transmission unit configured to transmit the offset set by the offset setting unit and the encoded data generated by the encoding unit.
- the transmission unit transmits the offset set by the offset setting unit as a parameter set of the encoded data.
- the transmission unit collects the plurality of offsets set by the offset setting unit and transmits the offsets as the parameter set.
- the image processing device (14) The image processing device according to (13), wherein the transmission unit transmits the offset set by the offset setting unit as a sequence parameter set of the encoded data. (15) The image processing device according to (13) or (14), wherein the transmission unit transmits the offset set by the offset setting unit as a picture parameter set of the encoded data. (16) The image processing device according to any one of (13) to (15), wherein the transmission unit transmits the offset set by the offset setting unit as an adaptation parameter set of the encoded data. (17) The image processing device according to any one of (11) to (16), wherein the transmission unit transmits the offset set by the offset setting unit as a slice header of the encoded data.
- the offset setting unit sets the quantization parameter offset for the color difference signal based on the quantization parameter for the luminance signal according to the size or shape of the transform unit when orthogonally transforming the image data
- An encoding unit encodes the image data
- a quantization parameter offset for a color difference signal based on a quantization parameter for a luminance signal, which is set according to the size or shape of a transform unit when image data is orthogonally transformed, and the image data A receiving unit for receiving encoded data that has been encoded; A decoding unit for decoding the encoded data received by the receiving unit; Using the quantization parameter for the chrominance signal obtained from the quantization parameter for the luminance signal using the offset extracted from the encoded data received by the receiving unit, the encoding unit performs the encoding.
- An image processing apparatus comprising: an inverse quantization unit that inversely quantizes the quantized orthogonal transform coefficient of the image data obtained by decoding the data.
- An image processing method for an image processing apparatus An offset of the quantization parameter for the color difference signal based on the quantization parameter for the luminance signal, which is set according to the size or shape of the transform unit when the image data is orthogonally transformed by the receiving unit, and the image data And encoded data obtained by encoding
- a decoding unit for decoding the received encoded data An inverse quantization unit uses the quantization parameter for the color difference signal, which is obtained from the quantization parameter for the luminance signal, using the offset extracted from the received encoded data.
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Abstract
Description
1.第1の実施の形態(画像符号化装置)
2.第2の実施の形態(画像復号装置)
3.第3の実施の形態(多視点画像符号化・多視点画像復号装置)
4.第4の実施の形態(階層画像符号化・階層画像復号装置)
5.第5の実施の形態(コンピュータ)
6.第6の実施の形態(テレビジョン受像機)
7.第7の実施の形態(携帯電話機)
8.第8の実施の形態(記録再生装置)
9.第9の実施の形態(撮像装置)
10.スケーラブル符号化の応用例
<画像符号化装置>
図1は、本技術を適用した画像処理装置である画像符号化装置の主な構成例を示すブロック図である。
次に、量子化について説明する。量子化部105は、係数データに対して量子化ステップで除算した結果を整数値に丸める処理である量子化を行う。量子化部105は、この量子化により係数の値を小さくすることができる。したがって、画像符号化装置100は、この量子化結果の係数(量子化値)を符号化することにより、量子化前の直交変換係数を符号化する場合よりも、符号量を低減させることができる。
次に、色差信号に対する量子化処理について述べる。
ところで、AVCにおいては、符号化の処理単位(符号化単位)として、マクロブロックとサブマクロブロックによる階層構造が規定されている。しかしながら、このマクロブロックサイズを16画素×16画素とするのは、次世代符号化方式の対象となるような、UHD(Ultra High Definition;4000画素×2000画素)といった大きな画枠に対しては、最適ではない。
上述したように、符号化側の装置において量子化に用いられた量子化パラメータ(QP)は、復号側の装置に伝送される。例えば、HEVCの場合、量子化パラメータQPをCU単位で伝送することが可能である。上述したようにCUは階層化構造を有し、LCU内に複数の大きさのCUを形成することができる。画像符号化装置100は、このうち、任意の大きさ以上のCUについてのみ量子化パラメータを伝送させるようにすることができる。
上述したように色差信号に対する量子化パラメータは、輝度信号に対する量子化パラメータから生成される。したがって、色差信号に対する量子化パラメータも、輝度信号に対する量子化パラメータと同様に、符号量をより低減させようと、より大きなブロックほど、より大きな値が設定される。
図7は、図1の直交変換部104および量子化部105の主な構成例を示すブロック図である。
次に、以上のような画像符号化装置100により実行される各処理の流れについて説明する。最初に、図9のフローチャートを参照して、符号化処理の流れの例を説明する。
次に図10のフローチャートを参照して、図9のステップS107において実行される直交変換量子化処理の流れの例を説明する。
<画像復号装置>
図11は、本技術を適用した画像処理装置である画像復号装置の主な構成例を示すブロック図である。図11に示される画像復号装置200は、上述した画像符号化装置100に対応し、画像符号化装置100が画像データを符号化して生成したビットストリーム(符号化データ)を正しく復号し、復号画像を生成する。
図12は、図11の逆量子化部203の主な構成例を示すブロック図である。
次に、以上のような画像復号装置200により実行される各処理の流れについて説明する。最初に、図13のフローチャートを参照して、復号処理の流れの例を説明する。
次に、図13のステップS203において実行される逆量子化逆直交変換処理の流れの例を、図14のフローチャートを参照して説明する。
以上においては、画像符号化装置100および画像復号装置200のそれぞれにおいて、chroma_qp_index_offsetが求められるように説明したが、これに限らず、例えば、符号化側の装置(画像符号化装置100)が、自身が設定したchroma_qp_index_offsetを、復号側の装置(画像復号装置200)に伝送し、復号側の装置(画像復号装置200)がそのchroma_qp_index_offsetを利用して色差信号に対する量子化パラメータを求めるようにしても良い。
<多視画像点符号化・多視点画像復号への適用>
上述した一連の処理は、多視点画像符号化・多視点画像復号に適用することができる。図15は、多視点画像符号化方式の一例を示す。
図16は、上述した多視点画像符号化を行う多視点画像符号化装置を示す図である。図16に示されるように、多視点画像符号化装置600は、符号化部601、符号化部602、および多重化部603を有する。
図17は、上述した多視点画像復号を行う多視点画像復号装置を示す図である。図17に示されるように、多視点画像復号装置610は、逆多重化部611、復号部612、および復号部613を有する。
<階層画像点符号化・階層画像復号への適用>
上述した一連の処理は、階層画像符号化・階層画像復号に適用することができる。図18は、階層画像符号化方式の一例を示す。
図19は、上述した階層画像符号化を行う階層画像符号化装置を示す図である。図19に示されるように、階層画像符号化装置620は、符号化部621、符号化部622、および多重化部623を有する。
図20は、上述した階層画像復号を行う階層画像復号装置を示す図である。図20に示されるように、階層画像復号装置630は、逆多重化部631、復号部632、および復号部633を有する。
<コンピュータ>
上述した一連の処理は、ハードウエアにより実行させることもできるし、ソフトウエアにより実行させることもできる。この場合、例えば、図21に示されるようなコンピュータとして構成されるようにしてもよい。
<テレビジョン装置>
図22は、上述した実施形態を適用したテレビジョン装置の概略的な構成の一例を示している。テレビジョン装置900は、アンテナ901、チューナ902、デマルチプレクサ903、デコーダ904、映像信号処理部905、表示部906、音声信号処理部907、スピーカ908、外部インタフェース909、制御部910、ユーザインタフェース911、及びバス912を備える。
<携帯電話機>
図23は、上述した実施形態を適用した携帯電話機の概略的な構成の一例を示している。携帯電話機920は、アンテナ921、通信部922、音声コーデック923、スピーカ924、マイクロホン925、カメラ部926、画像処理部927、多重分離部928、記録再生部929、表示部930、制御部931、操作部932、及びバス933を備える。
<記録再生装置>
図24は、上述した実施形態を適用した記録再生装置の概略的な構成の一例を示している。記録再生装置940は、例えば、受信した放送番組の音声データ及び映像データを符号化して記録媒体に記録する。また、記録再生装置940は、例えば、他の装置から取得される音声データ及び映像データを符号化して記録媒体に記録してもよい。また、記録再生装置940は、例えば、ユーザの指示に応じて、記録媒体に記録されているデータをモニタ及びスピーカ上で再生する。このとき、記録再生装置940は、音声データ及び映像データを復号する。
<撮像装置>
図25は、上述した実施形態を適用した撮像装置の概略的な構成の一例を示している。撮像装置960は、被写体を撮像して画像を生成し、画像データを符号化して記録媒体に記録する。
<第1のシステム>
次に、スケーラブル符号化(階層符号化)されたスケーラブル符号化データの具体的な利用例について説明する。スケーラブル符号化は、例えば、図26に示される例のように、伝送するデータの選択のために利用される。
また、スケーラブル符号化は、例えば、図27に示される例のように、複数の通信媒体を介する伝送のために利用される。
また、スケーラブル符号化は、例えば、図28に示される例のように、符号化データの記憶に利用される。
(1) 画像データを直交変換する際の変換単位の大きさまたは形状に応じて、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットを設定するオフセット設定部と、
前記オフセット設定部により設定された前記オフセットを用いて前記輝度信号に対する量子化パラメータから求められた、前記色差信号に対する量子化パラメータを用いて、前記画像データの直交変換係数を量子化する量子化部と
を備える画像処理装置。
(2) 前記オフセット設定部は、より大きな前記変換単位に対して、より細かい量子化ステップにより量子化が行われるように、前記オフセットを設定する
前記(1)に記載の画像処理装置。
(3) 前記オフセット設定部は、より大きな前記変換単位の前記オフセットを、より小さな値に設定する
前記(2)に記載の画像処理装置。
(4) 前記オフセット設定部は、前記画像データが符号化された符号化データのビットレートに応じて、より参照され易い大きさの直交変換係数に対して、より細かい量子化ステップにより量子化が行われるように、前記オフセットを設定する
前記(1)乃至(3)のいずれかに記載の画像処理装置。
(5) 前記オフセット設定部は、前記変換単位の大きさに応じて、予め定められた前記オフセットの初期値を補正する
前記(1)乃至(4)のいずれかに記載の画像処理装置。
(6) 前記オフセット設定部は、長方形の変換単位に対する前記オフセットとして、前記変換単位と、同じ若しくは近似する大きさの正方形の変換単位に対する前記オフセットの値を設定する
前記(1)乃至(5)のいずれかに記載の画像処理装置。
(7) 前記オフセット設定部は、前記画像データを直交変換する際の変換単位の大きさおよび形状に応じて、前記オフセットを設定する
前記(1)乃至(5)のいずれかに記載の画像処理装置。
(8) 画像処理装置の画像処理方法であって、
オフセット設定部が、画像データを直交変換する際の変換単位の大きさまたは形状に応じて、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットを設定し、
量子化部が、設定された前記オフセットを用いて前記輝度信号に対する量子化パラメータから求められた、前記色差信号に対する量子化パラメータを用いて、前記画像データの直交変換係数を量子化する
画像処理方法。
(9) 画像データを直交変換する際の変換単位の大きさまたは形状に応じて、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットを設定するオフセット設定部と、
前記オフセット設定部により設定された前記オフセットを用いて前記輝度信号に対する量子化パラメータから求められた、前記色差信号に対する量子化パラメータを用いて、前記画像データの量子化された直交変換係数を逆量子化する逆量子化部と
を備える画像処理装置。
(10) 画像処理装置の画像処理方法であって、
オフセット設定部が、画像データを直交変換する際の変換単位の大きさまたは形状に応じて、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットを設定し、
逆量子化部が、設定された前記オフセットを用いて前記輝度信号に対する量子化パラメータから求められた、前記色差信号に対する量子化パラメータを用いて、前記画像データの量子化された直交変換係数を逆量子化する
画像処理方法。
(11) 画像データを直交変換する際の変換単位の大きさまたは形状に応じて、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットを設定するオフセット設定部と、
前記画像データを符号化する符号化部と、
前記オフセット設定部により設定された前記オフセットと、前記符号化部により生成された符号化データとを伝送する伝送部と
を備える画像処理装置。
(12) 前記伝送部は、前記オフセット設定部により設定された前記オフセットを、前記符号化データのパラメータセットとして伝送する
前記(11)に記載の画像処理装置。
(13) 前記伝送部は、前記オフセット設定部により設定された複数の前記オフセットを、1つにまとめて、前記パラメータセットとして伝送する
前記(12)に記載の画像処理装置。
(14) 前記伝送部は、前記オフセット設定部により設定された前記オフセットを、前記符号化データのシーケンスパラメータセットとして伝送する
前記(13)に記載の画像処理装置。
(15) 前記伝送部は、前記オフセット設定部により設定された前記オフセットを、前記符号化データのピクチャパラメータセットとして伝送する
前記(13)または(14)に記載の画像処理装置。
(16) 前記伝送部は、前記オフセット設定部により設定された前記オフセットを、前記符号化データのアダプテーションパラメータセットとして伝送する
前記(13)乃至(15)のいずれかに記載の画像処理装置。
(17) 前記伝送部は、前記オフセット設定部により設定された前記オフセットを、前記符号化データのスライスヘッダとして伝送する
前記(11)乃至(16)のいずれかに記載の画像処理装置。
(18) 画像処理装置の画像処理方法であって、
オフセット設定部が、画像データを直交変換する際の変換単位の大きさまたは形状に応じて、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットを設定し、
符号化部が、前記画像データを符号化し、
伝送部が、設定された前記オフセットと、生成された符号化データとを伝送する
画像処理方法。
(19) 画像データを直交変換する際の変換単位の大きさまたは形状に応じて設定された、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットと、前記画像データを符号化した符号化データとを受け取る受け取り部と、
前記受け取り部により受け取られた前記符号化データを復号する復号部と、
前記受け取り部により受け取られた前記符号化データから抽出された前記オフセットを用いて前記輝度信号に対する量子化パラメータから求められた、前記色差信号に対する量子化パラメータを用いて、前記復号部により前記符号化データが復号されて得られた、前記画像データの量子化された直交変換係数を逆量子化する逆量子化部と
を備える画像処理装置。
(20) 画像処理装置の画像処理方法であって、
受け取り部が、画像データを直交変換する際の変換単位の大きさまたは形状に応じて設定された、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットと、前記画像データを符号化した符号化データとを受け取り、
復号部が、受け取られた前記符号化データを復号し、
逆量子化部が、受け取られた前記符号化データから抽出された前記オフセットを用いて前記輝度信号に対する量子化パラメータから求められた、前記色差信号に対する量子化パラメータを用いて、前記符号化データが復号されて得られた、前記画像データの量子化された直交変換係数を逆量子化する
画像処理方法。
Claims (20)
- 画像データを直交変換する際の変換単位の大きさまたは形状に応じて、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットを設定するオフセット設定部と、
前記オフセット設定部により設定された前記オフセットを用いて前記輝度信号に対する量子化パラメータから求められた、前記色差信号に対する量子化パラメータを用いて、前記画像データの直交変換係数を量子化する量子化部と
を備える画像処理装置。 - 前記オフセット設定部は、より大きな前記変換単位に対して、より細かい量子化ステップにより量子化が行われるように、前記オフセットを設定する
請求項1に記載の画像処理装置。 - 前記オフセット設定部は、より大きな前記変換単位の前記オフセットを、より小さな値に設定する
請求項2に記載の画像処理装置。 - 前記オフセット設定部は、前記画像データが符号化された符号化データのビットレートに応じて、より参照され易い大きさの直交変換係数に対して、より細かい量子化ステップにより量子化が行われるように、前記オフセットを設定する
請求項1に記載の画像処理装置。 - 前記オフセット設定部は、前記変換単位の大きさに応じて、予め定められた前記オフセットの初期値を補正する
請求項1に記載の画像処理装置。 - 前記オフセット設定部は、長方形の変換単位に対する前記オフセットとして、前記変換単位と、同じ若しくは近似する大きさの正方形の変換単位に対する前記オフセットの値を設定する
請求項1に記載の画像処理装置。 - 前記オフセット設定部は、前記画像データを直交変換する際の変換単位の大きさおよび形状に応じて、前記オフセットを設定する
請求項1に記載の画像処理装置。 - 画像処理装置の画像処理方法であって、
オフセット設定部が、画像データを直交変換する際の変換単位の大きさまたは形状に応じて、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットを設定し、
量子化部が、設定された前記オフセットを用いて前記輝度信号に対する量子化パラメータから求められた、前記色差信号に対する量子化パラメータを用いて、前記画像データの直交変換係数を量子化する
画像処理方法。 - 画像データを直交変換する際の変換単位の大きさまたは形状に応じて、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットを設定するオフセット設定部と、
前記オフセット設定部により設定された前記オフセットを用いて前記輝度信号に対する量子化パラメータから求められた、前記色差信号に対する量子化パラメータを用いて、前記画像データの量子化された直交変換係数を逆量子化する逆量子化部と
を備える画像処理装置。 - 画像処理装置の画像処理方法であって、
オフセット設定部が、画像データを直交変換する際の変換単位の大きさまたは形状に応じて、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットを設定し、
逆量子化部が、設定された前記オフセットを用いて前記輝度信号に対する量子化パラメータから求められた、前記色差信号に対する量子化パラメータを用いて、前記画像データの量子化された直交変換係数を逆量子化する
画像処理方法。 - 画像データを直交変換する際の変換単位の大きさまたは形状に応じて、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットを設定するオフセット設定部と、
前記画像データを符号化する符号化部と、
前記オフセット設定部により設定された前記オフセットと、前記符号化部により生成された符号化データとを伝送する伝送部と
を備える画像処理装置。 - 前記伝送部は、前記オフセット設定部により設定された前記オフセットを、前記符号化データのパラメータセットとして伝送する
請求項11に記載の画像処理装置。 - 前記伝送部は、前記オフセット設定部により設定された複数の前記オフセットを、1つにまとめて、前記パラメータセットとして伝送する
請求項12に記載の画像処理装置。 - 前記伝送部は、前記オフセット設定部により設定された前記オフセットを、前記符号化データのシーケンスパラメータセットとして伝送する
請求項13に記載の画像処理装置。 - 前記伝送部は、前記オフセット設定部により設定された前記オフセットを、前記符号化データのピクチャパラメータセットとして伝送する
請求項13に記載の画像処理装置。 - 前記伝送部は、前記オフセット設定部により設定された前記オフセットを、前記符号化データのアダプテーションパラメータセットとして伝送する
請求項13に記載の画像処理装置。 - 前記伝送部は、前記オフセット設定部により設定された前記オフセットを、前記符号化データのスライスヘッダとして伝送する
請求項11に記載の画像処理装置。 - 画像処理装置の画像処理方法であって、
オフセット設定部が、画像データを直交変換する際の変換単位の大きさまたは形状に応じて、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットを設定し、
符号化部が、前記画像データを符号化し、
伝送部が、設定された前記オフセットと、生成された符号化データとを伝送する
画像処理方法。 - 画像データを直交変換する際の変換単位の大きさまたは形状に応じて設定された、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットと、前記画像データを符号化した符号化データとを受け取る受け取り部と、
前記受け取り部により受け取られた前記符号化データを復号する復号部と、
前記受け取り部により受け取られた前記符号化データから抽出された前記オフセットを用いて前記輝度信号に対する量子化パラメータから求められた、前記色差信号に対する量子化パラメータを用いて、前記復号部により前記符号化データが復号されて得られた、前記画像データの量子化された直交変換係数を逆量子化する逆量子化部と
を備える画像処理装置。 - 画像処理装置の画像処理方法であって、
受け取り部が、画像データを直交変換する際の変換単位の大きさまたは形状に応じて設定された、輝度信号に対する量子化パラメータを基準とする、色差信号に対する量子化パラメータのオフセットと、前記画像データを符号化した符号化データとを受け取り、
復号部が、受け取られた前記符号化データを復号し、
逆量子化部が、受け取られた前記符号化データから抽出された前記オフセットを用いて前記輝度信号に対する量子化パラメータから求められた、前記色差信号に対する量子化パラメータを用いて、前記符号化データが復号されて得られた、前記画像データの量子化された直交変換係数を逆量子化する
画像処理方法。
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