WO2014007281A1 - カラー撮像素子及び撮像装置 - Google Patents
カラー撮像素子及び撮像装置 Download PDFInfo
- Publication number
- WO2014007281A1 WO2014007281A1 PCT/JP2013/068232 JP2013068232W WO2014007281A1 WO 2014007281 A1 WO2014007281 A1 WO 2014007281A1 JP 2013068232 W JP2013068232 W JP 2013068232W WO 2014007281 A1 WO2014007281 A1 WO 2014007281A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- color
- filter
- filters
- pixels
- array
- Prior art date
Links
- 238000003384 imaging method Methods 0.000 title claims abstract description 67
- 239000003086 colorant Substances 0.000 claims description 63
- 238000002834 transmittance Methods 0.000 claims description 30
- 230000003287 optical effect Effects 0.000 claims description 17
- 238000006243 chemical reaction Methods 0.000 claims description 13
- 238000003491 array Methods 0.000 claims description 6
- 238000012545 processing Methods 0.000 abstract description 47
- 230000000875 corresponding effect Effects 0.000 description 48
- 238000000034 method Methods 0.000 description 19
- 230000008569 process Effects 0.000 description 16
- 230000035945 sensitivity Effects 0.000 description 13
- 230000003595 spectral effect Effects 0.000 description 10
- 230000000694 effects Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 238000012937 correction Methods 0.000 description 4
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 230000002596 correlated effect Effects 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 241000579895 Chlorostilbon Species 0.000 description 2
- 230000000295 complement effect Effects 0.000 description 2
- 229910052876 emerald Inorganic materials 0.000 description 2
- 239000010976 emerald Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000006837 decompression Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000003252 repetitive effect Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 230000011664 signaling Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/1462—Coatings
- H01L27/14621—Colour filter arrangements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/80—Camera processing pipelines; Components thereof
- H04N23/84—Camera processing pipelines; Components thereof for processing colour signals
- H04N23/843—Demosaicing, e.g. interpolating colour pixel values
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
- H04N25/10—Circuitry of solid-state image sensors [SSIS]; Control thereof for transforming different wavelengths into image signals
- H04N25/11—Arrangement of colour filter arrays [CFA]; Filter mosaics
- H04N25/13—Arrangement of colour filter arrays [CFA]; Filter mosaics characterised by the spectral characteristics of the filter elements
- H04N25/133—Arrangement of colour filter arrays [CFA]; Filter mosaics characterised by the spectral characteristics of the filter elements including elements passing panchromatic light, e.g. filters passing white light
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
- H04N25/10—Circuitry of solid-state image sensors [SSIS]; Control thereof for transforming different wavelengths into image signals
- H04N25/11—Arrangement of colour filter arrays [CFA]; Filter mosaics
- H04N25/13—Arrangement of colour filter arrays [CFA]; Filter mosaics characterised by the spectral characteristics of the filter elements
- H04N25/134—Arrangement of colour filter arrays [CFA]; Filter mosaics characterised by the spectral characteristics of the filter elements based on three different wavelength filter elements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
- H04N25/10—Circuitry of solid-state image sensors [SSIS]; Control thereof for transforming different wavelengths into image signals
- H04N25/11—Arrangement of colour filter arrays [CFA]; Filter mosaics
- H04N25/13—Arrangement of colour filter arrays [CFA]; Filter mosaics characterised by the spectral characteristics of the filter elements
- H04N25/135—Arrangement of colour filter arrays [CFA]; Filter mosaics characterised by the spectral characteristics of the filter elements based on four or more different wavelength filter elements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N2209/00—Details of colour television systems
- H04N2209/04—Picture signal generators
- H04N2209/041—Picture signal generators using solid-state devices
- H04N2209/042—Picture signal generators using solid-state devices having a single pick-up sensor
- H04N2209/045—Picture signal generators using solid-state devices having a single pick-up sensor using mosaic colour filter
Definitions
- the present invention relates to a color image pickup device and an image pickup apparatus, and more particularly, to a color image pickup device capable of reducing the occurrence of color moire and increasing the resolution, and an image pickup apparatus using such a color image pickup device.
- a single color filter is provided on each pixel, so each pixel has only single color information. For this reason, since the output image of the single-chip color image sensor becomes a RAW image (mosaic image), a multi-channel image is obtained by a process of interpolating the missing color pixels from the surrounding pixels (demosaic processing). .
- the problem in this case is the reproduction characteristics of the high-frequency image signal, and the color image sensor is more likely to cause aliasing in the captured image as compared with the monochrome image sensor. For this reason, it is an important issue to widen the reproduction band and increase the resolution while reducing the occurrence of color moire (false color).
- the primary color Bayer array which is the color array of color filters most widely used in single-plate color image sensors, arranges green (G) pixels in a checkered pattern and arranges red (R) and blue (B) in line-sequential fashion. is doing. For this reason, there is a problem in reproduction accuracy when a high-frequency signal is generated in the oblique direction for the G signal and in the horizontal and vertical directions for the R and B signals.
- a black and white vertical stripe pattern (high-frequency image) as shown in part (A) of FIG. 22 is incident on a color imaging device having a Bayer array color filter shown in part (B) of FIG.
- R is a light flat
- B is a dark flat
- G is a light and shade mosaic color image. That is, although the image is originally a black and white image and does not cause a density difference (level difference) between RGB, depending on the color arrangement and the input frequency, the image is colored.
- an optical low-pass filter made of a birefringent material such as crystal is disposed in front of the color image pickup device, and this is avoided by optically dropping high frequencies.
- coloring due to folding of the high-frequency signal can be reduced, but there is a problem that the resolution is lowered due to its adverse effect.
- the color filter array of the color image sensor is configured such that an arbitrary pixel of interest satisfies an arrangement restriction condition in which any of the three colors including the color of the pixel of interest and the four sides of the pixel of interest are adjacent.
- Patent Document 1 A color imaging device having a random color arrangement has been proposed (Patent Document 1).
- JP 2000-308080 A JP 2005-136766 A Japanese Patent Laid-Open No. 11-285012 JP-A-8-23543
- the color imaging device described in Patent Document 1 has a problem that since the filter arrangement is random, it is necessary to optimize each random pattern when performing the demosaic process in the subsequent stage, and the demosaic process becomes complicated.
- the random arrangement is effective for low-frequency color moire, but is not effective for false colors in the high-frequency part.
- the demosaicing process is a process of calculating (converting into simultaneous equations) all the RGB color information for each pixel from the RGB mosaic image associated with the color filter array of the single-plate color image sensor, and is demosaicing. Also referred to as processing or synchronization processing (same in this specification).
- the color imaging device described in Patent Document 2 has a problem that the pixel reproducibility in the limit resolution region (especially in an oblique direction) is not good because G pixels (luminance pixels) are arranged in a checkered pattern.
- the color imaging device described in Patent Document 3 has an advantage that generation of false colors can be suppressed because filters of all colors exist on an arbitrary straight line.
- the color image sensor described in Patent Document 3 has a problem that high-frequency reproducibility is lower than that of the Bayer array because the ratio of the number of RGB pixels is equal. In the case of the Bayer array, the ratio of the number of G pixels that contributes most to obtain a luminance signal is twice the number of R and B pixels.
- the ratio of the number of G pixels to the number of R and B pixels is 6 times higher than the Bayer array, and there is a filter line of only G pixels in the horizontal or vertical direction. Therefore, it is not effective for the false color of the high frequency part in the horizontal or vertical direction.
- the present invention has been made in view of such circumstances, and can reduce the occurrence of false colors and increase the resolution, and can simplify the subsequent processing as compared with the conventional random arrangement.
- An object is to provide a color imaging device.
- Another object of the present invention is to provide an image pickup apparatus using such a color image pickup element.
- a color image pickup device includes a color filter on a plurality of pixels formed of photoelectric conversion elements arranged in a first direction and a second direction perpendicular to the first direction.
- a single-plate type color image pickup device provided, wherein the color filters are arranged so that the color filters correspond to N ⁇ N (N is an odd number of 5 or more) pixels in the first direction and the second direction.
- the color filter corresponds to a first color of one or more colors, including a basic array pattern arranged in a pattern, the basic array pattern being repeatedly arranged in the first direction and the second direction.
- a first filter that includes a first filter and a second filter corresponding to a second color that is two or more colors whose contribution ratio for obtaining a luminance signal is lower than that of the first color, and that corresponds to the first filter;
- the ratio of the total number of pixels of one color is the second field.
- the first filter has a first direction, a second direction, a first direction, and a second direction of the arrangement of the color filters.
- One or more of the second filters of each color of the second color are arranged in a filter line in each direction including the third direction and the fourth direction inclined with respect to the direction of
- One second filter is arranged in each filter line in the first direction and the second direction, and the second filter of at least one color in the array of color filters has a first direction to a fourth direction.
- a second filter or a first filter having a color different from that of the second filter is arranged adjacently.
- a color image pickup device for achieving the object of the present invention includes a color image on a plurality of pixels formed by photoelectric conversion devices arranged in a first direction and a second direction perpendicular to the first direction.
- a single-plate type color image pickup device in which a filter is arranged, and the color filter array corresponds to N ⁇ N pixels (N is an odd number of 5 or more) in the first direction and the second direction.
- the color filter has a transmittance peak in the wavelength range from 480 nm to 570 nm.
- the color filter has a basic arrangement pattern that is arranged in such a manner that the basic arrangement pattern is repeated in the first direction and the second direction.
- At least one filter line in each direction including one direction, a second direction, a third direction and a fourth direction inclined with respect to the first direction and the second direction,
- Each of the second filters of each color of the second color is arranged one by one in each filter line in the first direction and the second direction in the basic array pattern, and at least one color in the array of color filters In the second filter, a second filter or a first filter having a color different from that of the second filter is adjacently arranged in each direction from the first direction to the fourth direction.
- a color image pickup device for achieving the object of the present invention includes a color image on a plurality of pixels formed by photoelectric conversion devices arranged in a first direction and a second direction perpendicular to the first direction.
- a single-plate type color image pickup device in which a filter is arranged, and the color filter array corresponds to N ⁇ N pixels (N is an odd number of 5 or more) in the first direction and the second direction.
- the basic filter pattern is arranged in a repeating pattern in the first direction and the second direction, and the color filter has one or more first colors.
- the ratio of the total number of pixels of one color is larger than the ratio of the number of pixels of each color of the second color corresponding to the second filter, and the first filter is connected to the first direction of the arrangement of the color filters.
- One or more filter lines in each direction including the second direction, the third direction and the fourth direction inclined with respect to the first direction and the second direction, and the second color
- Each of the second filters of each color is arranged in each filter line in the first direction and the second direction in the basic array pattern, and the second filter of at least one color in the array of color filters.
- a second filter or a first filter having a color different from that of the second filter is adjacently arranged in each direction from the first direction to the fourth direction.
- a color image pickup device for achieving the object of the present invention includes a color image on a plurality of pixels formed by photoelectric conversion devices arranged in a first direction and a second direction perpendicular to the first direction.
- a single-plate type color image pickup device in which a filter is arranged, and the color filter array corresponds to N ⁇ N pixels (N is an odd number of 5 or more) in the first direction and the second direction.
- the basic filter pattern is arranged in a repeating pattern in the first direction and the second direction, and the color filter contributes most to the luminance signal among the three primary colors.
- a second filter, and the first filter The ratio of the total number of pixels of each corresponding color of the first color is larger than the ratio of the number of pixels of each color of the second color corresponding to the second filter.
- One or more are arranged in the filter line in each direction including the first direction, the second direction, the third direction and the fourth direction inclined with respect to the first direction and the second direction.
- Each of the second filters of each color of the second color is arranged one by one in each filter line in the first direction and the second direction in the basic array pattern, and at least one in the array of color filters.
- a second filter or a first filter of a different color from the second filter is arranged adjacent to each other in the first direction to the fourth direction. Yes.
- the reproduction accuracy of the demosaic process in the high frequency region can be improved.
- the color filter arrangement can be performed according to the repetition pattern when performing the demosaic processing in the subsequent stage. Compared with the random arrangement, the subsequent processing can be simplified.
- the ratio of the number of pixels of the first color corresponding to the first filter is larger than the ratio of the number of pixels of each color of the second color corresponding to the second filter, aliasing is performed. Can be suppressed, and high frequency reproducibility is also good.
- the second filter of at least one color is adjacent to the first filter or the second filter of a color different from that of the second filter in each direction from the first direction to the fourth direction. Therefore, the second filters are evenly arranged in the color filter array. Thereby, the demosaic processing of the pixels of the second color can be performed with high accuracy.
- the contribution ratio of the first color for obtaining the luminance signal is preferably 50% or more, and the contribution ratio of the second color for obtaining the luminance signal is preferably less than 50%. Since one or more first filters having a higher contribution ratio for obtaining the luminance signal than the second filter are arranged in the filter lines in each direction from the first direction to the fourth direction of the color filter array. The reproduction accuracy of demosaic processing in the high frequency region can be improved.
- the second filter or the first filter having a color different from that of the second filter is adjacently arranged in each direction of the second filter of each color of the second color. Is preferred.
- the second filters of the respective colors are evenly arranged in the color filter array.
- the basic array pattern includes a filter array formed by arranging a first filter and a second filter corresponding to each color of the second color in the first direction, and a plurality of filter arrays are arranged in the second direction. It is preferable that the position of the second filter corresponding to each color of the second color is shifted in the first direction for each filter row in the basic array pattern. As a result, the second filters of the respective colors are evenly arranged in the color filter array.
- the second filter corresponding to each color of the second color is separately arranged in the color filter array. It is preferable that the diagonal filter arrays of the respective colors arranged at equal intervals along the fifth direction are arranged at equal intervals along the second direction. As a result, the second filters of the respective colors are evenly arranged in the color filter array.
- ⁇ tan ⁇ 1 (1/2) Expression (1)
- Each of the second filters corresponding to each color of the second color is preferably arranged in one or more filter lines in the third direction and the fourth direction in the color filter array. Thereby, color moire (false color) that can be generated by an input image having a high-frequency component in the third and fourth directions can be reduced.
- a second filter or a first filter having a color different from that of the second filter is adjacent to each direction of the second filter of one of the second colors. It is preferable that they are arranged.
- the second filters of one color are equally arranged in the color filter array.
- the basic array pattern includes a square array corresponding to 2 ⁇ 2 pixels configured by the first filter.
- the array of color filters includes a square array corresponding to 2 ⁇ 2 pixels made of the first filter, and therefore, using the pixel value of 2 ⁇ 2 pixels, It is possible to determine a direction having a high correlation among the directions.
- the second color of the second color is included in the arrangement of the color filters. It is preferable that the diagonal filter array formed by arranging the filters at equal intervals along the fifth direction is arranged at equal intervals along the second direction. As a result, the second filters of one color are equally arranged in the color filter array.
- ⁇ tan ⁇ 1 (1/2) Expression (1)
- the third direction and the fourth direction are preferably different from each other by 45 ° with respect to the first direction and the second direction.
- the first color includes at least one of green and transparent.
- the second color preferably includes red and blue.
- An imaging apparatus for achieving the object of the present invention includes an imaging optical system, a color imaging element on which a subject image is formed via the imaging optical system, and image data generation for generating image data indicating the formed subject image
- a color imaging device according to any one of the above aspects.
- the first filter is disposed in the filter line in each direction from the first direction to the fourth direction of the arrangement of the color filters, and the first filter corresponding to the first filter is provided.
- the ratio of the number of pixels of one color is made larger than the ratio of the number of pixels of the second color corresponding to the second filter of two or more colors other than the first color. For this reason, it is possible to improve the reproduction accuracy of the demosaic process in the high frequency region and suppress aliasing.
- one or more second filters corresponding to each of the second or more second colors are included in each filter line in the first direction and the second direction of the color filter array in the basic array pattern. It was arranged. For this reason, the generation of color moire (false color) can be reduced and high resolution can be achieved. Furthermore, since the second filters of at least one color are evenly arranged in the color filter array, it is possible to accurately perform the demosaic processing of the pixels corresponding to the second filters.
- the color filter array can be processed according to the repeat pattern when performing the demosaic process in the subsequent stage. .
- the subsequent processing can be simplified as compared with the conventional random arrangement.
- FIG. 1 is a block diagram showing an electrical configuration of the digital camera.
- FIG. 2 is a front view of the imaging surface of the color image sensor.
- FIG. 3 is a front view of the color filter array of the first embodiment.
- FIG. 4 is an enlarged view of the basic array pattern in FIG.
- FIG. 5 is an explanatory diagram for explaining an oblique filter array.
- FIG. 6 is an enlarged view of a part of FIG.
- FIG. 7 is an explanatory diagram for explaining a plurality of types of basic array patterns.
- FIG. 8 is a front view of the color filter array of the second embodiment.
- FIG. 9 is an explanatory diagram for explaining an oblique filter array according to the second embodiment.
- FIG. 10 is a front view of the color filter array of the 2-1 embodiment.
- FIG. 11 is an enlarged view of the basic array pattern of the color filter array of the 2-2 embodiment.
- FIG. 12 is an enlarged view of the basic arrangement pattern of the color filter arrangement according to the second to third embodiments.
- FIG. 13 is a front view of the color filter array of the third embodiment having a transparent filter.
- FIG. 14 is a graph showing the spectral sensitivity characteristics of the color filter array of the third embodiment.
- FIG. 15 is a front view of a color filter array according to the fourth embodiment having two types of G filters.
- FIG. 16 is a graph showing the spectral sensitivity characteristics of the color filter array of the fourth embodiment.
- FIG. 17 is a front view of a color filter array of a fifth embodiment having an emerald filter.
- FIG. 18 is a graph showing the spectral sensitivity characteristics of the color filter array of the fifth embodiment.
- FIG. 19 is a front view of a basic array pattern of another embodiment in which the basic array pattern of the first embodiment is changed to an array pattern corresponding to 7 ⁇ 7 pixels.
- FIG. 20 is a front view of a basic array pattern of another embodiment in which the basic array pattern of the second embodiment is changed to an array pattern corresponding to 7 ⁇ 7 pixels.
- FIG. 21 is a front view of a color filter array according to another embodiment in which the color filter array is a honeycomb array.
- FIG. 22 is a diagram used for explaining a problem of a color imaging device having a color filter with a conventional Bayer array.
- FIG. 23 is another diagram used for explaining the problem of a color imaging device having a color filter with a conventional Bayer array.
- FIG. 1 is a block diagram of a digital camera 9 (image pickup apparatus) including a color image pickup device according to the present invention.
- the digital camera 9 broadly includes a photographing optical system 10, a color imaging device 12, a photographing processing unit 14, an image processing unit 16, a driving unit 18, a control unit 20, and the like.
- the photographing optical system 10 forms a subject image on the image pickup surface of the color image pickup device 12.
- the color imaging device 12 is a so-called single-plate type including a plurality of pixels composed of photoelectric conversion elements two-dimensionally arranged on the imaging surface and a color filter provided above the light receiving surface of each pixel. It is a color image sensor.
- “to upper” and “upper” indicate directions on the side where subject light is incident on the imaging surface of the color imaging element 12.
- the subject image formed on the color image sensor 12 is converted into a signal charge corresponding to the amount of incident light by the photoelectric conversion element of each pixel.
- the signal charge accumulated in each photoelectric conversion element is sequentially read out from the color imaging element 12 as a voltage signal (image signal) corresponding to the signal charge based on a drive pulse given from the drive unit 18 according to a command from the control unit 20.
- the image signals read from the color image sensor 12 are R, G, and B signals that indicate red (R), green (G), and blue (B) mosaic images corresponding to the color filter array of the color image sensor 12.
- the color image sensor 12 may be another type of image sensor such as a CCD (Charge-Coupled Device) -type image sensor or a CMOS (Complementary-Metal-Oxide-Semiconductor) -type image sensor.
- CCD Charge-Coupled Device
- CMOS Complementary-Metal-Oxide-Semiconductor
- the image signal read from the color image sensor 12 is input to the imaging processing unit 14 (image data generation unit).
- the imaging processing unit 14 is a correlated double sampling circuit (CDS) for removing reset noise included in the image signal, an AGC circuit for amplifying the image signal and controlling it to a certain level, and an A / D. It has a converter.
- the imaging processing unit 14 performs correlated double sampling processing and amplification on the input image signal, and then outputs RAW data converted to a digital image signal to the image processing unit 16.
- the color image sensor 12 is a MOS type image sensor, the A / D converter is often built in the image sensor, and the correlated double sampling may not be necessary.
- the image processing unit 16 (image data generation unit) includes a white balance correction circuit, a gamma correction circuit, a demosaic processing circuit (all RGB RGB images for each pixel from the RGB mosaic image associated with the color filter array of the single-plate color image sensor 12). And a luminance / color difference signal generation circuit, a contour correction circuit, a color correction circuit, and the like.
- the image processing unit 16 performs necessary signal processing on the RAW data of the mosaic image input from the imaging processing unit 14 in accordance with a command from the control unit 20, and generates an RGB pixel signal having all RGB color information for each pixel. Based on this, image data (YUV data) composed of luminance data (Y data) and color difference data (Cr, Cb data) is generated.
- the image data generated by the image processing unit 16 is subjected to compression processing conforming to the JPEG standard for still images by a compression / decompression processing circuit, and compression processing conforming to the MPEG2 standard for moving images. After that, it is recorded on a recording medium (not shown) such as a memory card, and is output and displayed on a display means (not shown) such as a liquid crystal monitor.
- a recording medium such as a memory card
- a display means such as a liquid crystal monitor.
- the recording medium is not limited to the one that can be attached to and detached from the digital camera 9, and may be a built-in magneto-optical recording medium
- the display means is not limited to that provided in the digital camera 9. It may be a connected external display.
- FIG. 2 a plurality of pixels 21 including photoelectric conversion elements PD that are two-dimensionally arranged in the horizontal direction and the vertical direction are provided on the imaging surface of the color imaging element 12.
- the horizontal direction corresponds to one of the first direction and the second direction of the present invention
- the vertical direction corresponds to the other direction of the first direction and the second direction of the present invention.
- a color filter array 22 composed of color filters disposed on each pixel 21 is provided on the image pickup surface of the color image pickup device 12.
- the color filter array 22 includes three primary color filters (hereinafter referred to as R filter, G filter, and B filter) 23R, 23G, and 23B of red (R), green (G), and blue (B). Then, any of the RGB filters 23R, 23G, and 23B is disposed on each pixel 21.
- R pixel the pixel in which the R filter 23R is disposed
- G pixel the pixel in which the G filter 23G is disposed
- B filter 23B the pixel in which the B filter 23B is disposed is referred to as “B pixel”.
- the G color corresponds to the first color of the present invention
- the G filter 23G corresponds to the first filter of the present invention
- the R and B colors correspond to the second color of the present invention
- the RB filters 23R and 23B correspond to the second filter of the present invention.
- One of the R filter 23R and the B filter 23B belonging to the second color filter is also referred to as an “RB filter” below.
- the color filter array 22 has the following features (1), (2), (3), (4), (5), and (6).
- the color filter array 22 includes a basic array pattern P1 that is a square array pattern corresponding to 5 ⁇ 5 pixels, and the basic array pattern P1 has a horizontal direction (H) and a vertical direction ( V) is repeatedly arranged. Therefore, in the color filter array 22, the R filter 23R, the G filter 23G, and the B filter 23B of each color are arrayed with a predetermined periodicity. For this reason, when performing demosaic processing or the like of the R, G, and B signals read from the color image sensor 12, processing can be performed according to a repetitive pattern. As a result, the subsequent processing can be simplified as compared with the conventional random arrangement.
- the color filter array after the thinning process can be the same as the color filter array before the thinning process, and a common processing circuit is used. can do.
- each of the filter rows 25a to 25e is formed by horizontally arranging three G filters 23G, one R filter 23R, and one B filter 23B, and has the following characteristics (2) to (6).
- the arrangement of the RGB filters 23R, 23G, and 23B is determined so as to satisfy the above.
- G filters 23G are arranged in the respective filter lines in the horizontal (H), vertical (V), and diagonal (NE, NW) directions.
- NE means the diagonally upper right (lower left) direction, and corresponds to one of the third direction and the fourth direction of the present invention.
- NW means a diagonally lower right (upper left) direction and corresponds to the other direction of the third direction and the fourth direction of the present invention. Since the RGB filters 23R, 23G, and 23B have a square shape, the NE direction and the NW direction are directions of 45 ° with respect to the horizontal direction and the vertical direction, respectively.
- this angle can be increased or decreased in accordance with the increase or decrease in the length of each side in the horizontal direction or the vertical direction of the RGB filters 23R, 23G, and 23B.
- the diagonal direction is diagonal (NE, NW direction).
- the NE direction and the NW direction are 45 ° with respect to the horizontal direction and the vertical direction, respectively.
- the diagonal direction of the rectangular lattice corresponds to an oblique direction (NE, NW direction).
- the contribution rate for obtaining the luminance (Y) signal (the above-mentioned luminance data) is higher for the G color than for the R and B colors. That is, the contribution ratio of the R color and the B color is lower than that of the G color.
- the above-described image processing unit 16 generates a Y signal according to the following formula (1) from RGB pixel signals having all RGB color information for each pixel.
- the following formula (1) is a formula that is generally used for generating the Y signal in the color image sensor 12.
- the contribution rate of the G color to the luminance signal is 60%, so that the G color has a higher contribution rate than the R color (contribution rate 30%) and the B color (contribution rate 10%). . Therefore, the G color is the color that contributes most to the luminance signal among the three primary colors.
- the numbers of R pixels, G pixels, and B pixels corresponding to the RGB filters 23R, 23G, and 23B in the basic array pattern P1 are 5 pixels, 15 pixels, and 5 pixels, respectively. Therefore, since the ratio of the number of RGB pixels is 1: 3: 1, the ratio of the number of G pixels that contributes most to obtain a luminance signal is the ratio of the number of R pixels and B pixels. Bigger than.
- the ratio between the number of G pixels and the number of R and B pixels is different, and in particular, the ratio of the number of G pixels that contributes most to obtain a luminance signal is the number of R and B pixels. Therefore, the aliasing can be suppressed and the high frequency reproducibility can be improved.
- One R filter 23R and one B filter 23B are arranged in each filter line in the horizontal direction (H) and vertical direction (V) of the color filter array 22 in the basic array pattern P1.
- the R filter 23R and the B filter 23B are arranged in the filter lines in the horizontal direction (H) and the vertical direction (V) of the color filter array 22, respectively, occurrence of color moire (false color) can be reduced. it can.
- an optical low-pass filter for suppressing generation of false colors can be prevented from being arranged in the optical path from the incident surface of the imaging optical system 10 to the imaging surface of the color imaging element 12, or even when the optical low-pass filter is applied.
- the optical low-pass filter may not be provided. As a result, the resolution can be maintained.
- the R filter 23R satisfying the above feature (4) has its horizontal (H), vertical (V), and diagonal (NE, NW) directions (hereinafter referred to as “directions (H, V, NE, NW)” as appropriate.
- the G filter 23G or the B filter 23B is disposed adjacent to the abbreviation “)”. Further, in the B filter 23B satisfying the above feature (4), the G filter 23G or the R filter 23R is adjacently disposed in each direction (H, V, NE, NW). Accordingly, the RB filters 23R and 23B are provided with filters of different colors adjacent to each direction (H, V, NE, NW) (feature (5)). That is, the R filters 23R of the same color or the B filters 23B of the same color are not arranged adjacent to each direction (H, V, NE, NW).
- the RB filters 23R and 23B in the basic array pattern P1 are shifted in the horizontal direction for each of the filter rows 25a to 25e. is doing. Specifically, the RB filters 23R and 23B are arranged adjacent to each other in the horizontal direction in any one of the filter rows 25a to 25e, for example, the filter row 25a.
- the RB filters 23R and 23B in the filter row 25b are arranged so as to be shifted by two pixel intervals in the horizontal direction with respect to the RB filters 23R and 23B in the filter row 25a.
- the positions of the RB filters 23R and 23B are sequentially shifted from the filter row 25d toward the filter row 25e by two pixel intervals in the same direction.
- the “pixel interval” refers to a pixel interval (pitch) from the center point of the reference pixel (one pixel) to the center point of adjacent pixels.
- the oblique filter rows 27R and 27B are adjacent to each other in the oblique direction, and the adjacent oblique filter rows 27R and 27B are arranged at equal intervals in the vertical direction (V) in the color filter array 22.
- the filter line L R oblique direction is a fifth direction of the present invention
- L B is inclined theta ° with respect to the horizontal direction (H).
- This ⁇ is represented by the following formula (2).
- “the number of pixel intervals in the vertical direction” and “the number of pixel intervals in the horizontal direction” are the number of pixel intervals in the horizontal direction and the vertical direction of the R filter 23R, or the horizontal direction and the vertical of the B filter 23B. The number of pixel intervals in the direction.
- the RB filters 23R and 23B are arranged in the color filter array 22 so as to satisfy the above characteristics (4) and (5), the RB filters 23R and 23B are equal in the color filter array 22, respectively. Placed in. Thereby, the demosaic process of R pixel and B pixel can be performed with high accuracy.
- the RB filters 23R and 23B are arranged in the color filter array 22 so as to satisfy the above features (4) and (5), they are on the diagonal direction (NE, NW) filter lines of the color filter array 22. Also, one or more RB filters 23R and 23B are arranged. That is, in each oblique (NE, NW) direction, filter lines including the R filter 23R and the B filter 23B are periodically arranged adjacently.
- the fact that the filter lines are adjacent in the oblique direction means that when a filter having a square with one side length of 1 is used, the interval between the filter lines is ⁇ 2 / 2 pixel interval. .
- the RB filters 23R and 23B are also arranged in the (NE, NW) filter lines in the diagonal direction, respectively, the high frequency component is applied in the diagonal direction (NE, NW) as compared with the case where only the feature (4) is satisfied.
- Color moire false color
- a color that can be generated by an input image having a high-frequency component in the oblique direction can be reduced. Accordingly, even if an optical low-pass filter having anisotropy in the oblique (NE, NW) direction is not disposed between the imaging optical system 10 and the imaging surface, a color that can be generated by an input image having a high-frequency component in the oblique direction.
- an image with reduced moire can be reproduced, or even when an optical low-pass filter is applied, a specific color moire (with a weak function of cutting high frequency components to prevent false color generation) (False color) can be suppressed.
- the optical low-pass filter may not be provided. As a result, the resolution in the oblique direction can be prevented from being impaired.
- a basic array pattern obtained by shifting the basic array pattern P1 by one pixel each in the horizontal direction (H) and the vertical direction (V) is P1 ′, and a basic array pattern obtained by shifting two pixels each.
- these basic array patterns P1 ′ and P1 ′′ are the same color filter array 22 even if they are repeatedly arranged in the horizontal direction (H) and the vertical direction (V).
- the basic array pattern P1 shown in FIGS. 3 and 4 is referred to as a basic array pattern for convenience.
- the demosaic processing in the subsequent stage is simplified, the reproduction accuracy of the demosaic processing in the high frequency region is improved, and the demosaic It is possible to suppress aliasing during processing and improve high frequency reproducibility, improve the accuracy of demosaic processing of R pixels and B pixels, and increase the resolution.
- the color imaging device of the second embodiment is the above except that it includes a color filter array 30 having the following features (5a) and (7) instead of the features (5) and (6).
- the configuration is basically the same as that of the first embodiment. For this reason, the same reference numerals are given to the same functions and configurations as those in the first embodiment, and the description thereof is omitted.
- the color filter array 30 includes a basic array pattern P2 in which the RGB filters 23R, 23G, and 23B are arrayed in an array pattern corresponding to 5 ⁇ 5 pixels, and the basic array pattern P2 includes the horizontal direction (H) and the vertical direction ( V) is repeatedly arranged. For this reason, the color filter array 30 has the above-described feature (1).
- One or more G filters 23G are arranged in each filter line in the horizontal (H), vertical (V), and diagonal (NE, NW) directions of the color filter array 30. Further, the ratio of the number of RGB pixels in the basic array pattern P2 is 1: 3: 1 as in the first embodiment. Further, at least one R filter 23R and one B filter 23B are arranged in each filter line in the horizontal direction (H) and the vertical direction (V) of the color filter array 30 in the basic array pattern P2. Therefore, the color filter array 30 has the characteristics (2) to (4) described above.
- the color filter array 30 that satisfies the aforementioned characteristics (4) and (5a), diagonal filter train consisting by equally spaced along the R filter 23R obliquely filter line L R 27R are arranged at equal intervals along the vertical direction (V).
- V vertical direction
- the basic array pattern P2 of the color filter array 30 having the above-described features (2) to (4) and (5a) has a square array corresponding to 2 ⁇ 2 pixels provided with the G filter 23G. 32 is included.
- a 2 ⁇ 2 G pixel corresponding to such a square array 32 is taken out, the difference absolute value of the pixel value of the G pixel in the horizontal direction (H), the difference absolute value of the pixel value of the G pixel in the vertical direction (V),
- the absolute difference value is small in the horizontal direction (H), the vertical direction (V), and the oblique direction (NE, NW). It can be determined that there is a correlation in direction.
- the color filter array 30 uses the information of the G pixel with the minimum pixel interval to determine the direction with high correlation among the horizontal direction (H), the vertical direction (V), and the diagonal direction (NE, NW). Can do.
- This direction discrimination result can be used for a process of interpolating from surrounding pixels (demosaic process).
- a direction determination processing unit may be provided in the demosaic processing circuit (image processing unit 16) described above, and the direction determination processing unit may perform direction determination.
- the color filter array 30 of the present invention has the features (5a) and (7) in addition to the above-described features (1) to (4), simplification of the demosaicing process in the subsequent stage, Improvement of reproduction accuracy of demosaic processing in the high frequency region, suppression of aliasing during demosaic processing and improvement of high frequency reproducibility, higher resolution, improved accuracy of demosaic processing of R pixels, and higher correlation Discrimination becomes possible.
- the color filter array having the above-described features (1) to (4), (5a), and (7) is not limited to the one having the array pattern shown in FIG. May be.
- the color filter array 34 is formed by repeatedly arranging a basic array pattern P3 different from the basic array pattern P2 in the horizontal direction (H) and the vertical direction (V).
- the basic array pattern P3 is basically the same as the basic array pattern P2 except that the arrangement of the G filter 23G and the B filter 23B in the hatched portion in the drawing is different. Therefore, the color filter array 34 has the same features (1) to (4), (5a), and (7) as the above-described color filter array 30, and the same effect as the color filter array 30 is obtained. It is done.
- a color filter array is constituted by the basic array pattern P2 ′ (see FIG. 11) or the basic array pattern P3 ′ (see FIG. 12).
- the basic array pattern P2 'shown in FIG. 11 is an array pattern obtained by reversing the arrangement of the R filter 23R and the B filter 23B in the basic array pattern P2.
- a basic array pattern P3 'shown in FIG. 12 is an array pattern obtained by reversing the arrangement of the R filter 23R and the B filter 23B in the basic array pattern P3. Accordingly, in the color filter array constituted by the basic array patterns P2 ′ and P3 ′, filters of different colors are adjacently arranged in the respective directions (H, V, NE, NW) of the B filter 23B. In the oblique (NE, NW) direction, R filters 23R of the same color are arranged adjacently (feature (5b)).
- the color filter array composed of the basic array patterns P2 ′ and P3 ′ has the characteristics (1) to (4), (5b), and (7). Therefore, the demosaic process of the B pixel instead of the R pixel is performed. Except for the point that the accuracy can be improved, the same effect as the color filter array of the second embodiment can be obtained.
- the G color G filter 23G is described as an example of the first filter having the first color of the present invention.
- the same effect can be obtained by using a filter that satisfies any of the following conditions (1) to (4) instead of a part.
- Condition (1) is that the contribution rate for obtaining the luminance signal is 50% or more.
- This contribution rate of 50% is a value determined to distinguish the first color (G color, etc.) from the second color (R, B color, etc.) of the present invention, and is used to obtain luminance data.
- the contribution rate of G color is 60% as shown in the above formula (1), the condition (1) is satisfied.
- the contribution ratio of colors other than the G color can also be obtained by experiments and simulations. Therefore, a filter having a color with a contribution ratio of 50% or more other than the G color can also be used as the first filter of the present invention. Note that the color having a contribution ratio of less than 50% is the second color (R color, B color, etc.) of the present invention, and the filter having this color is the second filter of the present invention.
- Condition (2) is that the peak of the transmittance of the filter is in the range of wavelengths from 480 nm to 570 nm.
- a value measured with a spectrophotometer is used as the transmittance of the filter.
- This wavelength range is a range defined for distinguishing between the first color (G color, etc.) and the second color (R, B color, etc.) of the present invention, and the aforementioned contribution ratio is relative. This is a range determined so that peaks such as R color and B color that become lower in general are not included, and peaks such as G color in which the contribution ratio is relatively higher are included.
- a filter having a transmittance peak in the wavelength range of 480 nm to 570 nm can be used as the first filter.
- a filter whose transmittance peak is outside the wavelength range of 480 nm or more and 570 nm or less is the second filter (R filter 23R, B filter 23B) of the present invention.
- Condition (3) is that the transmittance within the wavelength range of 500 nm to 560 nm is higher than the transmittance of the second filter (R filter 23R or B filter 23B). Also in this condition (3), the value measured with a spectrophotometer, for example, is used as the transmittance of the filter.
- the wavelength range of the condition (3) is also a range determined to distinguish the first color (G color, etc.) from the second color (R, B color, etc.) of the present invention.
- the transmittance of the filter having a color having the above-described contribution ratio that is relatively higher than that of the color, the B color, or the like is in a range that is higher than the transmittance of the RB filters 23R and 23B. Therefore, a filter having a relatively high transmittance within a wavelength range of 500 nm to 560 nm can be used as the first filter, and a filter having a relatively low transmittance can be used as the second filter.
- Condition (4) is that a filter of two or more colors including a color that contributes most to the luminance signal (for example, G color of RGB) among the three primary colors and a color different from the three primary colors is used as the first filter. Is to use. In this case, a filter corresponding to a color other than each color of the first filter is the second filter.
- the color imaging device of the third embodiment is the first embodiment except that the color imaging device includes white pixels (also referred to as clear pixels) that receive white light (light in the wavelength range of visible light) in addition to the RGB pixels.
- white pixels also referred to as clear pixels
- the configuration is basically the same as the form. For this reason, the same reference numerals are given to the same functions and configurations as those in the first embodiment, and the description thereof is omitted.
- the color image sensor of the third embodiment includes a color filter array 36 different from that of the first embodiment.
- the color filter array 36 includes a basic array pattern P4 in which the aforementioned RGB filters 23R, 23G, and 23B and the transparent filter 23W (first filter) are arrayed in an array pattern corresponding to 5 ⁇ 5 pixels.
- the array pattern P4 is repeatedly arranged in the horizontal and vertical directions (H, V). For this reason, the color filter array 36 has the above-described feature (1).
- the basic array pattern P4 has an array pattern in which a part of the G filter 23G of the basic array pattern P1 is replaced with a transparent filter 23W.
- the G filter 23G adjacent to the other G filter 23G in the horizontal and vertical directions (H, V) is replaced with a transparent filter 23W.
- a part of the G pixel is replaced with a white pixel.
- the transparent filter 23W is a transparent color (first color) filter.
- the transparent filter 23W is a filter that can transmit light corresponding to the wavelength range of visible light, and for example, has a transmittance of light of each color of RGB of 50% or more. Since the transmittance of the transparent filter 23W is higher than that of the G filter 23G, the contribution rate for obtaining the luminance signal is also higher than that of the G color (60%), and satisfies the above condition (1).
- the transmittance peak of the transparent filter 23W (the peak of the sensitivity of the white pixel) is in the wavelength range of 480 nm to 570 nm. Further, the transmittance of the transparent filter 23W is higher than the transmittance of the RB filters 23R and 23B within a wavelength range of 500 nm to 560 nm. For this reason, the transparent filter 23W also satisfies the above-described conditions (2) and (3). Note that the G filter 23G also satisfies the above-described conditions (1) to (3) as in the transparent filter 23W.
- the transparent filter 23W satisfies the above conditions (1) to (3), it can be used as the first filter of the present invention.
- the color filter array 36 a part of the G filter 23G corresponding to the G color that contributes most to the luminance signal among the three primary colors of RGB is replaced with the transparent filter 23W, so the above condition (4) is also satisfied. Yes.
- the color filter array 36 is basically the same as the color filter array 22 of the first embodiment except that a part of the G filter 23G is replaced with the transparent filter 23W as described above. Therefore, it has the same features (2) to (6) as the first embodiment. Therefore, the same effect as that described in the first embodiment can be obtained.
- the first filters including the G filter 23G and the transparent filter 23W are filter lines in the horizontal direction (H), vertical direction (V), and diagonal direction (NE, NW) of the color filter array 36. If one or more are included, the above feature (2) is satisfied.
- the color image sensor of the fourth embodiment has basically the same configuration as that of the first embodiment except that the color image sensor includes two types of G pixels. For this reason, the same reference numerals are given to the same functions and configurations as those in the first embodiment, and the description thereof is omitted.
- the color image sensor of the fourth embodiment includes a color filter array 40 different from that of the first embodiment.
- the color filter array 40 includes a basic array pattern P5 in which an R filter 23R, a first G filter 23G1, a second G filter 23G2 (first filter), and a B filter 23B are arrayed in an array pattern corresponding to 5 ⁇ 5 pixels.
- the basic array pattern P5 is repeatedly arranged in the horizontal and vertical directions (H, V). For this reason, the color filter array 40 has the above-described feature (1).
- the basic array pattern P5 has an array pattern in which each G filter 23G of the basic array pattern P1 of the first embodiment is replaced with the first G filter 23G1 or the second G filter 23G2.
- the first G filter 23G1 is arranged in an odd-numbered filter row in the horizontal direction
- the second G filter 23G2 is arranged in an even-numbered filter row in the horizontal direction.
- the first G filter 23G1 transmits G light in the first wavelength band
- the second G filter 23G2 transmits G light in the second wavelength band having a high correlation with the first G filter 23G1 (see FIG. 16).
- an existing G filter for example, the G filter 23G of the first embodiment
- a filter having a high correlation with the first G filter 23G1 can be used.
- the peak value of the spectral sensitivity curve of the second G filter 23G2 is preferably in the range of, for example, a wavelength of 500 nm to 535 nm (near the peak value of the spectral sensitivity curve of the existing G filter).
- a method described in Japanese Patent Application Laid-Open No. 2003-284084 is used as a method for determining the color filters of four colors (R, G1, G2, B).
- the color of the image acquired by the color imaging device of the fourth embodiment is set to four types, and the color information acquired is increased, so that only three types of colors (RGB) are acquired. Color can be expressed more accurately. That is, colors that look different to the eyes can be reproduced as different colors, and colors that appear to be the same can be reproduced as the same color (“color discriminability” can be improved).
- the transmittance of the first and second G filters 23G1 and 23G2 is basically the same as the transmittance of the G filter 23G of the first embodiment, the contribution rate for obtaining the luminance signal is higher than 50%. . Accordingly, the first and second G filters 23G1 and 23G2 satisfy the above-described condition (1).
- each G filter 23G1, 23G2 (sensitivity peak of each G pixel) is in the wavelength range of 480 nm or more and 570 nm or less. Further, the transmittance of each G filter 23G1, 23G2 is higher than the transmittance of the RB filters 23R, 23B within a wavelength range of 500 nm to 560 nm. For this reason, each G filter 23G1, 23G2 also satisfies the above-mentioned conditions (2), (3).
- the color filter array 40 is basically the same as the color filter array 22 of the first embodiment except that each of the G filters 23G1 and 23G2 is included, as described above.
- the arrangement and the number of the G filters 23G1 and 23G2 are not limited to the embodiment shown in FIG. 15, and may be changed as appropriate. Moreover, you may increase the kind of G filter to three or more types.
- the color imaging device of the fifth embodiment is the first embodiment except that the color imaging device includes E pixels that receive light of an emerald (E) color corresponding to the fourth color of the present invention in addition to the RGB pixels.
- E emerald
- the configuration is basically the same as the form. For this reason, the same reference numerals are given to the same functions and configurations as those in the first embodiment, and the description thereof is omitted.
- the color image sensor of the fifth embodiment includes a color filter array 44 different from that of the first embodiment.
- the color filter array 44 includes a basic array pattern P6 in which the RGB filters 23R, 23G, and 23B and the E filter 23E (first filter) described above are arrayed in an array pattern corresponding to 5 ⁇ 5 pixels.
- the array pattern P6 is repeatedly arranged in the horizontal and vertical directions (H, V). For this reason, the color filter array 44 has the above-described feature (1).
- the basic array pattern P6 has an array pattern in which the transparent filter 23W of the basic array pattern P4 of the third embodiment shown in FIG. 13 is replaced with an E filter 23E.
- the four-color color filter array 44 in which a part of the G filter 23G is replaced with the E filter 23E, it is possible to improve reproduction of high-frequency components of luminance, reduce jaggedness, and improve resolution. Can be possible.
- the peak of the transmittance of the E filter 23E (the peak of the sensitivity of the E pixel) is in the wavelength range of 480 nm to 570 nm. Further, the transmittance of the E filter 23E is higher than the transmittance of the RB filters 23R and 23B within a wavelength range of 500 nm to 560 nm. For this reason, the E filter 23E satisfies the above-mentioned conditions (2) and (3). Further, in the color filter array 44, a part of the G filter 23G corresponding to the G color that contributes most to the luminance signal among the three primary colors of RGB is replaced with the E filter 23E, so the above condition (4) is also satisfied. Yes.
- the E filter 23E has a peak on the shorter wavelength side than the G filter 23G, but has a peak on the longer wavelength side than the G filter 23G (a little yellowish color appears). In some cases.
- a filter satisfying the conditions of the present invention can be selected as appropriate. For example, an E filter 23E that satisfies the condition (1) can be selected.
- the color filter array 44 is basically the same as the color filter array 22 of the first embodiment except that a part of the G filter 23G is replaced with the E filter 23E as described above. Therefore, it has the same features (2) to (6) as the first embodiment. Therefore, the same effect as that described in the first embodiment can be obtained.
- the arrangement and number of the E filters 23E may be changed to a different arrangement and number from the embodiment shown in FIG.
- the first filters including the G filter 23G and the E filter 23E are filter lines in the horizontal direction (H), vertical direction (V), and diagonal direction (NE, NW) of the color filter array 44. If one or more are included, the above feature (2) is satisfied.
- the E filter 23E is used as the first filter of the present invention.
- some of the E filters 23E do not satisfy the above-described conditions (1) to (4), for example. . Therefore, such an E filter 23E may be used as the second filter of the present invention.
- Each color filter array of each of the above embodiments is arranged in an array pattern whose basic array pattern corresponds to 5 ⁇ 5 pixels.
- the basic array pattern P7 of the color filter array 48 shown in FIG. Like the basic array pattern P8 of the color filter array 50 shown in FIG. 20, it may be arranged in an array pattern corresponding to 7 ⁇ 7 pixels.
- the basic array pattern P7 is basically the same as the basic array pattern P1 except that the basic array pattern P1 of the first embodiment is expanded to 7 ⁇ 7 pixels, but further includes the square array 32 described above. ing. Accordingly, the color filter array 48 has the features (1) to (7) described above.
- the basic array pattern P8 is basically the same as the basic array pattern P2 except that the basic array pattern P2 of the second embodiment is expanded to 7 ⁇ 7 pixels. Accordingly, the color filter array 50 has the same features (1) to (4), (5a), and (7) as the color filter array 30 of the second embodiment.
- the basic array patterns P3 to P6 of the second to fifth embodiments may be arranged in an array pattern corresponding to 7 ⁇ 7 pixels.
- the basic array pattern of each embodiment may be arranged in an array pattern corresponding to 9 ⁇ 9 pixels, that is, the basic array pattern is an array pattern corresponding to N ⁇ N (N is an odd number of 5 or more) pixels. You may arrange with. However, even if N is increased, signal processing such as demosaicing becomes complicated, but a special effect by increasing the size of the basic array pattern cannot be obtained.
- the size of the basic array pattern is preferably 7 ⁇ 7 pixels or less, which is not too large, and the basic array pattern corresponding to 5 ⁇ 5 pixels is more preferable from the viewpoint of simplifying signal processing. preferable.
- Each color filter array of each of the above embodiments includes a basic array pattern in which color filters of each color are two-dimensionally arrayed in the horizontal direction (H) and the vertical direction (V), and this basic array pattern is in the horizontal direction (H ) And the vertical direction (V), but the present invention is not limited to this.
- a so-called honeycomb array-shaped basic array pattern P9 formed by two-dimensionally arranging RGB filters 23R, 23G, and 23B in an oblique direction (NE, NW) is included.
- An arrangement pattern in which the arrangement pattern P9 is repeatedly arranged in an oblique direction (NE, NW) may be used.
- the oblique directions (NE, NW) are the first and second directions of the present invention
- the horizontal and vertical directions (H, V) are the third and fourth directions of the present invention.
- Such a color filter array 52 is an array pattern in which the color filter array 22 of the first embodiment is rotated by 45 ° around the optical axis of the photographing optical system 10, and therefore the same features (1) as the first embodiment (1).
- the basic arrangement patterns P2 to P8 may be similarly arranged in the honeycomb arrangement.
- the color filter array including the primary color RGB color filters has been described.
- G is set to C (cyan), M (magenta), and Y (yellow) which are complementary colors of the primary color RGB.
- the present invention can also be applied to the color filter array of the four complementary color filters added.
- the color filter satisfying any one of the above conditions (1) to (4) is set as the first filter of the present invention, and the other color filter is set as the second filter.
- the color filter array of the color image sensor of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
- the color filter arrays of the above embodiments may be combined as appropriate.
- the first filter of the present invention a combination of at least two of the G filter 23G, the transparent filter 23W, the first and second G filters 23G1, 23G2, and the E filter 23E may be used. Filters of other colors that satisfy any one of the above conditions (1) to (4) may be used.
- filters of colors other than the RB filters 23R and 23B may be used as the second filter of the present invention.
- the color image sensor mounted on the digital camera has been described.
- the color image sensor mounted on various electronic devices (imaging devices) having a shooting function such as a smartphone, a mobile phone, and a PDA.
- the present invention can be applied.
- DESCRIPTION OF SYMBOLS 9 Digital camera, 12 ... Color imaging device, 21 ... Photoelectric conversion device, 22, 30, 34, 36, 40, 44, 48, 52 ... Color filter arrangement, 23R ... R filter, 23G ... G filter, 23G1 ... No. 1G filter, 23G2 ... 2nd G filter, 23B ... B filter, 23W ... transparent filter, 23E ... E filter, 32 ... square array, P1-P9 ... basic array pattern
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Power Engineering (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Color Television Image Signal Generators (AREA)
- Optical Filters (AREA)
- Solid State Image Pick-Up Elements (AREA)
Abstract
Description
θ=tan-1(1/2)・・・式(1)
第2の色の各色に対応する第2のフィルタのそれぞれは、カラーフィルタの配列内の第3の方向及び第4の方向のフィルタライン内に1つ以上配置されることが好ましい。これにより、第3及び第4の方向に高周波成分を有する入力像によって発生しうる色モワレ(偽色)を低減することができる。
θ=tan-1(1/2)・・・式(1)
カラーフィルタが正方形状である場合に、第3の方向及び第4の方向は第1の方向及び第2の方向に対してそれぞれ45°異なることが好ましい。
図1は本発明に係るカラー撮像素子を備えるデジタルカメラ9(撮像装置)のブロック図である。デジタルカメラ9は、大別して、撮影光学系10、カラー撮像素子12、撮影処理部14、画像処理部16、駆動部18、制御部20などを備えている。
図2に示すように、カラー撮像素子12の撮像面には、水平方向及び垂直方向に2次元配列された光電変換素子PDで構成される複数の画素21が設けられている。ここで、水平方向は本発明の第1の方向及び第2の方向のうちの一方向に相当し、垂直方向は本発明の第1の方向及び第2の方向のうちの他方向に相当する。
カラーフィルタ配列22は、下記の特徴(1)、(2)、(3)、(4)、(5)、及び(6)を有している。
図3及び図4に示すように、カラーフィルタ配列22は、5×5画素に対応する正方配列パターンとなる基本配列パターンP1を含み、この基本配列パターンP1が水平方向(H)及び垂直方向(V)に繰り返し配置されている。従って、カラーフィルタ配列22では、各色のRフィルタ23R、Gフィルタ23G、Bフィルタ23Bが所定の周期性をもって配列されている。このため、カラー撮像素子12から読み出されるR、G、B信号のデモザイク処理等を行う際に、繰り返しパターンにしたがって処理を行うことができる。その結果、従来のランダム配列に比べて後段の処理を簡略化することができる。
カラーフィルタ配列22では、その水平(H)、垂直(V)、及び斜め(NE,NW)方向の各フィルタライン内にGフィルタ23Gが配置されている。ここで、NEは斜め右上(左下)方向を意味し、本発明の第3の方向及び第4の方向のうちの一方向に相当する。また、NWは斜め右下(左上)方向を意味し、本発明の第3の方向及び第4の方向のうちの他方向に相当する。RGBフィルタ23R,23G,23Bは正方形状であるので、NE方向及びNW方向は水平方向、垂直方向に対してそれぞれ45°の方向となる。なお、この角度は、RGBフィルタ23R,23G,23Bの水平方向や垂直方向の各辺の長さの増減に応じて増減し得る。例えば、正方形状以外の矩形状のカラーフィルタを用いた場合には、その対角線方向が斜め(NE,NW方向)となる。なお、カラーフィルタが正方形状以外の矩形状であっても、このカラーフィルタあるいは画素を正方格子状に配置した場合には、NE方向及びNW方向は水平方向、垂直方向に対してそれぞれ45°の方向となる。さらに、複数の画素及びカラーフィルタが矩形格子状に配列されている場合には、その矩形格子の対角線の方向が斜め(NE,NW方向)に対応する。
このようなGフィルタ23Gが、カラーフィルタ配列22の水平(H)、垂直(V)、及び斜め(NE,NW)方向の各フィルタライン内に配置されるため、入力像において高周波となる方向によらず高周波領域でのデモザイク処理の再現精度を向上させることができる。
基本配列パターンP1内のRGBフィルタ23R,23G,23Bに対応するR画素、G画素、B画素の画素数は、それぞれ5画素、15画素、5画素になる。従って、RGB画素の各画素数の比率は1:3:1になるので、輝度信号を得るために最も寄与するG画素の画素数の比率は、R画素、B画素のそれぞれの画素数の比率よりも大きくなる。
Rフィルタ23R及びBフィルタ23Bは、それぞれ基本配列パターンP1内においてカラーフィルタ配列22の水平方向(H)、及び垂直方向(V)の各フィルタライン内に1つ配置されている。
上記の特徴(4)を満たすRフィルタ23Rは、その水平(H)、垂直(V)、及び斜め(NE,NW)方向の各方向(以下、適宜「各方向(H,V,NE,NW)」と略す)に、Gフィルタ23GまたはBフィルタ23Bが隣接して配置されている。また、上記の特徴(4)を満たすBフィルタ23Bは、その各方向(H,V,NE,NW)にGフィルタ23GまたはRフィルタ23Rが隣接して配置されている。従って、RBフィルタ23R,23Bには、それぞれ異なる色のフィルタが各方向(H,V,NE,NW)に隣接して配置されている(特徴(5))。すなわち、同色のRフィルタ23R同士または同色のBフィルタ23B同士が、各方向(H,V,NE,NW)に隣接して配置されることはない。
=tan-1(1/2)≒26°・・・式(2)
図5に戻って、カラーフィルタ配列22には、斜めフィルタ列27R,27Bがそれぞれ垂直方向(V)に沿って等間隔で配置される。その結果、カラーフィルタ配列22内には、RBフィルタ23R,23Bがそれぞれ均等(ほぼ均等を含む)に配置される。
また、上記の特徴(4)、(5)を満たすようにRBフィルタ23R,23Bをカラーフィルタ配列22内に配置した場合には、カラーフィルタ配列22の斜め方向(NE,NW)フィルタライン上にもRBフィルタ23R,23Bがそれぞれ1以上配置される。すなわち、各斜め(NE,NW)方向において、Rフィルタ23RとBフィルタ23Bを含むフィルタラインが隣接して周期的に配列している。ここで、斜め方向においてフィルタラインが隣接するとは、1辺の長さが1の正方形であるフィルタを使用した場合、フィルタラインとフィルタラインの間が√2/2画素間隔であることを意味する。
なお、図7に示すように、基本配列パターンP1を水平方向(H)、及び垂直方向(V)にそれぞれ1画素ずつシフトした基本配列パターンをP1’、それぞれ2画素ずつシフトした基本配列パターンをP1”とすると、これらの基本配列パターンP1’,P1”を水平方向(H)及び垂直方向(V)に繰り返し配置しても、同じカラーフィルタ配列22になる。このように、図3に示したカラーフィルタ配列22を構成可能な基本配列パターンは複数存在する。第1の実施形態では、図3及び図4に示した基本配列パターンP1を、便宜上、基本配列パターンという。
次に、図8を用いて本発明の第2実施形態のカラー撮像素子について説明を行う。なお、第2の実施形態のカラー撮像素子は、上記特徴(5)及び(6)の代わりに下記の特徴(5a)及び特徴(7)を有するカラーフィルタ配列30を備える点を除けば、上記第1実施形態と基本的には同じ構成である。このため、上記第1実施形態と機能・構成上同一のものについては、同一符号を付してその説明は省略する。
カラーフィルタ配列30は、RGBフィルタ23R,23G,23Bが5×5画素に対応する配列パターンで配列されてなる基本配列パターンP2を含み、この基本配列パターンP2が水平方向(H)及び垂直方向(V)に繰り返し配置されている。このため、カラーフィルタ配列30は前述の特徴(1)を有する。
カラーフィルタ配列30では、Rフィルタ23Rの各方向(H,V,NE,NW)に異なる色のフィルタが隣接して配置されているが、Bフィルタ23Bの斜め(NE,NW)方向には同色のBフィルタ23Bが配置されている。
図8に戻って、前述の特徴(2)~(4)、(5a)を有するカラーフィルタ配列30の基本配列パターンP2には、Gフィルタ23Gが設けられた2×2画素に対応する正方配列32が含まれている。
前述の特徴(1)~(4)、(5a)、(7)を有するカラーフィルタ配列は、図8に示した配列パターンを有するものに限定されず、これら各特徴を満たす範囲内で適宜変更してもよい。
上記カラーフィルタ配列30,34では、Rフィルタ23Rの各方向(H,V,NE,NW)に異なる色のフィルタを隣接配置しているが、Bフィルタ23Bの各方向(H,V,NE,NW)に異なる色のフィルタを隣接配置してもよい。この場合には、基本配列パターンP2’(図11参照)または基本配列パターンP3’(図12参照)によりカラーフィルタ配列を構成する。
上各記実施形態では、本発明の第1の色を有する第1のフィルタとしてG色のGフィルタ23Gを例に挙げて説明を行ったが、Gフィルタ23Gの代わりに、あるいはGフィルタ23Gの一部に代えて、下記条件(1)から条件(4)のいずれかを満たすフィルタを用いても同様の効果が得られる。
条件(1)は、輝度信号を得るための寄与率が50%以上であることである。この寄与率50%は、本発明の第1の色(G色など)と、第2の色(R、B色など)とを区別するために定めた値であって、輝度データを得るための寄与率がR色、B色などよりも相対的に高くなる色が「第1の色」に含まれるように定めた値である。G色の寄与率は上記式(1)に示したように60%となるので条件(1)を満たす。また、G色以外の色の寄与率についても実験やシミュレーションにより取得可能である。従って、G色以外で寄与率が50%以上となる色を有するフィルタも、本発明の第1のフィルタとして用いることができる。なお、寄与率が50%未満となる色は本発明の第2色(R色、B色など)となり、この色を有するフィルタが本発明の第2のフィルタとなる。
条件(2)は、フィルタの透過率のピークが波長480nm以上570nm以下の範囲内にあることである。フィルタの透過率は、例えば分光光度計で測定された値が用いられる。この波長範囲は、本発明の第1の色(G色など)と、第2の色(R、B色など)とを区別するために定められた範囲であって、前述の寄与率が相対的に低くなるR色、B色などのピークが含まれず、かつ寄与率が相対的に高くなるG色などのピークが含まれるように定められた範囲である。従って、透過率のピークが波長480nm以上570nm以下の範囲内にあるフィルタを第1のフィルタとして用いることができる。なお、透過率のピークが波長480nm以上570nm以下の範囲外となるフィルタが本発明の第2のフィルタ(Rフィルタ23R、Bフィルタ23B)となる。
条件(3)は、波長500nm以上560nm以下の範囲内での透過率が第2のフィルタ(Rフィルタ23RやBフィルタ23B)の透過率よりも高いことである。この条件(3)においても、フィルタの透過率は例えば分光光度計で測定された値が用いられる。この条件(3)の波長範囲も、本発明の第1の色(G色など)と、第2の色(R、B色など)とを区別するために定められた範囲であって、R色やB色などよりも前述の寄与率が相対的に高くなる色を有するフィルタの透過率が、RBフィルタ23R、23Bなどの透過率よりも高くなる範囲である。従って、透過率が波長500nm以上560nm以下の範囲内で相対的に高いフィルタを第1のフィルタとして用い、透過率が相対的に低いフィルタを第2のフィルタとして用いることができる。
条件(4)は、3原色のうち最も輝度信号に寄与する色(例えばRGBのうちのG色)と、この3原色とは異なる色とを含む2色以上のフィルタを、第1のフィルタとして用いることである。この場合には、第1のフィルタの各色以外の色に対応するフィルタが第2のフィルタとなる。
次に、図13を用いて本発明の第3実施形態のカラー撮像素子について説明を行う。なお、第3の実施形態のカラー撮像素子は、RGB画素以外に白色光(可視光の波長域の光)を受光する白色画素(クリア画素ともいう)を備える点を除けば、上記第1実施形態と基本的には同じ構成である。このため、上記第1実施形態と機能・構成上同一のものについては、同一符号を付してその説明は省略する。
第3実施形態のカラー撮像素子は、第1実施形態とは異なるカラーフィルタ配列36を備えている。カラーフィルタ配列36は、前述のRGBフィルタ23R,23G,23B、及び透明フィルタ23W(第1のフィルタ)が5×5画素に対応する配列パターンで配列されてなる基本配列パターンP4を含み、この基本配列パターンP4が水平及び垂直方向(H、V)に繰り返し配置されている。このため、カラーフィルタ配列36は前述の特徴(1)を有する。
次に、図15を用いて本発明の第4実施形態のカラー撮像素子について説明を行う。なお、第4の実施形態のカラー撮像素子は、2種類のG画素を備えている点を除けば、上記第1実施形態と基本的には同じ構成である。このため、上記第1実施形態と機能・構成上同一のものについては、同一符号を付してその説明は省略する。
第4実施形態のカラー撮像素子は、第1実施形態とは異なるカラーフィルタ配列40を備えている。カラーフィルタ配列40は、Rフィルタ23R、第1Gフィルタ23G1及び第2Gフィルタ23G2(第1のフィルタ)、Bフィルタ23Bが5×5画素に対応する配列パターンで配列されてなる基本配列パターンP5を含み、この基本配列パターンP5が水平及び垂直方向(H、V)に繰り返し配置されている。このため、カラーフィルタ配列40は前述の特徴(1)を有する。
次に、図17を用いて本発明の第5実施形態のカラー撮像素子について説明を行う。なお、第5の実施形態のカラー撮像素子は、RGB画素以外に、本発明の第4色に対応するエメラルド(E)色の光を受光するE画素を備える点を除けば、上記第1実施形態と基本的には同じ構成である。このため、上記第1実施形態と機能・構成上同一のものについては、同一符号を付してその説明は省略する。
第5実施形態のカラー撮像素子は、第1実施形態とは異なるカラーフィルタ配列44を備えている。カラーフィルタ配列44は、前述のRGBフィルタ23R,23G,23B、及びEフィルタ23E(第1のフィルタ)が5×5画素に対応する配列パターンで配列されてなる基本配列パターンP6を含み、この基本配列パターンP6が水平及び垂直方向(H、V)に繰り返し配置されている。このため、カラーフィルタ配列44は前述の特徴(1)を有する。
上記各施形態の各カラーフィルタ配列は、その基本配列パターンが5×5画素に対応する配列パターンで配列されているが、例えば、図19に示すカラーフィルタ配列48の基本配列パターンP7、及び図20に示すカラーフィルタ配列50の基本配列パターンP8のように、7×7画素に対応する配列パターンで配列されていてもよい。
Claims (16)
- 第1の方向及び第1の方向に垂直な第2の方向に配列された光電変換素子で構成される複数の画素上に、カラーフィルタが配設されてなる単板式のカラー撮像素子であって、
前記カラーフィルタの配列は、前記カラーフィルタが前記第1の方向及び第2の方向にN×N(Nは5以上の奇数)画素に対応する配列パターンで配列されてなる基本配列パターンを含み、かつ当該基本配列パターンが前記第1の方向及び第2の方向に繰り返されて配置されてなり、
前記カラーフィルタは、1色以上の第1の色に対応する第1のフィルタと、輝度信号を得るための寄与率が前記第1の色よりも低い2色以上の第2の色に対応する第2のフィルタとを含み、かつ前記第1のフィルタに対応する前記第1の色の全画素数の比率が、前記第2のフィルタに対応する前記第2の色の各色の画素数の比率よりも大きくなり、
前記第1のフィルタは、前記カラーフィルタの配列の前記第1の方向と、前記第2の方向と、前記第1の方向及び第2の方向に対して傾いた第3の方向及び第4の方向とを含む各方向のフィルタライン内に1つ以上配置され、
前記第2の色の各色の前記第2のフィルタのそれぞれは、前記基本配列パターン内の前記第1の方向及び第2の方向の各フィルタライン内に1つずつ配置され、
前記カラーフィルタの配列内で少なくとも1色の前記第2のフィルタには、その前記第1の方向から前記第4の方向の各方向に、当該第2のフィルタとは異なる色の前記第2のフィルタまたは前記第1のフィルタが隣接して配置されているカラー撮像素子。 - 第1の方向及び第1の方向に垂直な第2の方向に配列された光電変換素子で構成される複数の画素上に、カラーフィルタが配設されてなる単板式のカラー撮像素子であって、
前記カラーフィルタの配列は、前記カラーフィルタが前記第1の方向及び第2の方向にN×N(Nは5以上の奇数)画素に対応する配列パターンで配列されてなる基本配列パターンを含み、かつ当該基本配列パターンが前記第1の方向及び第2の方向に繰り返されて配置されてなり、
前記カラーフィルタは、透過率のピークが波長480nm以上570nm以下の範囲内にある1色以上の第1の色に対応する第1のフィルタと、透過率のピークが前記範囲の外にある2色以上の第2の色に対応する第2のフィルタとを含み、かつ前記第1のフィルタに対応する第1の色の全画素数の比率が、前記第2のフィルタに対応する第2の色の各色の画素数の比率よりも大きくなり、
前記第1のフィルタは、前記カラーフィルタの配列の前記第1の方向と、前記第2の方向と、前記第1の方向及び第2の方向に対して傾いた第3の方向及び第4の方向とを含む各方向のフィルタライン内に1つ以上配置され、
前記第2の色の各色の前記第2のフィルタのそれぞれは、前記基本配列パターン内の前記第1の方向及び第2の方向の各フィルタライン内に1つずつ配置され、
前記カラーフィルタの配列内で少なくとも1色の前記第2のフィルタには、その前記第1の方向から前記第4の方向の各方向に、当該第2のフィルタとは異なる色の前記第2のフィルタまたは前記第1のフィルタが隣接して配置されているカラー撮像素子。 - 第1の方向及び第1の方向に垂直な第2の方向に配列された光電変換素子で構成される複数の画素上に、カラーフィルタが配設されてなる単板式のカラー撮像素子であって、
前記カラーフィルタの配列は、前記カラーフィルタが前記第1の方向及び第2の方向にN×N(Nは5以上の奇数)画素に対応する配列パターンで配列されてなる基本配列パターンを含み、かつ当該基本配列パターンが前記第1の方向及び第2の方向に繰り返されて配置されてなり、
前記カラーフィルタは、1色以上の第1の色に対応する第1のフィルタと、波長500nm以上560nm以下の範囲内で透過率が前記第1のフィルタよりも低くなる2色以上の第2の色に対応する第2のフィルタとを含み、かつ前記第1のフィルタに対応する第1の色の全画素数の比率が、前記第2のフィルタに対応する第2の色の各色の画素数の比率よりも大きくなり、
前記第1のフィルタは、前記カラーフィルタの配列の前記第1の方向と、前記第2の方向と、前記第1の方向及び第2の方向に対して傾いた第3の方向及び第4の方向とを含む各方向のフィルタライン内に1つ以上配置され、
前記第2の色の各色の前記第2のフィルタのそれぞれは、前記基本配列パターン内の前記第1の方向及び第2の方向の各フィルタライン内に1つずつ配置され、
前記カラーフィルタの配列内で少なくとも1色の前記第2のフィルタには、その前記第1の方向から前記第4の方向の各方向に、当該第2のフィルタとは異なる色の前記第2のフィルタまたは前記第1のフィルタが隣接して配置されているカラー撮像素子。 - 第1の方向及び第1の方向に垂直な第2の方向に配列された光電変換素子で構成される複数の画素上に、カラーフィルタが配設されてなる単板式のカラー撮像素子であって、
前記カラーフィルタの配列は、前記カラーフィルタが前記第1の方向及び第2の方向にN×N(Nは5以上の奇数)画素に対応する配列パターンで配列されてなる基本配列パターンを含み、かつ当該基本配列パターンが前記第1の方向及び第2の方向に繰り返されて配置されてなり、
前記カラーフィルタは、3原色のうち最も輝度信号に寄与する色と前記3原色とは異なる色の第4色とを含む2色以上の第1の色に対応する第1のフィルタと、前記第1の色以外の2色以上の第2の色に対応する第2のフィルタとを含み、かつ前記第1のフィルタに対応する前記第1の色の各色の全画素数の比率が、前記第2のフィルタに対応する前記第2の色の各色の画素数の比率よりも大きくなり、
前記第1のフィルタは、前記カラーフィルタの配列の前記第1の方向と、前記第2の方向と、前記第1の方向及び第2の方向に対して傾いた第3の方向及び第4の方向とを含む各方向のフィルタライン内に1つ以上配置され、
前記第2の色の各色の前記第2のフィルタのそれぞれは、前記基本配列パターン内の前記第1の方向及び第2の方向の各フィルタライン内に1つずつ配置され、
前記カラーフィルタの配列内で少なくとも1色の前記第2のフィルタには、その前記第1の方向から前記第4の方向の各方向に、当該第2のフィルタとは異なる色の前記第2のフィルタまたは前記第1のフィルタが隣接して配置されているカラー撮像素子。 - 輝度信号を得るための前記第1の色の寄与率は50%以上であり、輝度信号を得るための前記第2の色の寄与率は50%未満である請求項1記載のカラー撮像素子。
- 前記基本配列パターン内では、前記第2の色の各色の前記第2のフィルタの前記各方向に、当該第2のフィルタとは異なる色の前記第2のフィルタまたは前記第1のフィルタが隣接して配置されている請求項1から5のいずれか1項記載のカラー撮像素子。
- 前記基本配列パターンは、前記第1のフィルタ及び前記第2の色の各色に対応する前記第2のフィルタを前記第1の方向に配列させてなるフィルタ列を含み、かつ複数の前記フィルタ列を前記第2の方向に配列させてなるものであり、
前記基本配列パターン内の前記フィルタ列毎に前記第2の色の各色に対応する前記第2のフィルタの位置を前記第1の方向にずらして配置している請求項6記載のカラー撮像素子。 - 前記第1の方向に対して式(1)で示されるθ°異なる方向を第5の方向としたときに、前記カラーフィルタの配列には、前記第2の色の各色に対応する前記第2のフィルタを別々に前記第5の方向に沿って等間隔で配置してなる各色の斜めフィルタ配列が、それぞれ前記第2の方向に沿って等間隔で配置されている請求項7記載のカラー撮像素子。
θ=tan-1(1/2)・・・式(1) - 前記第2の色の各色に対応する前記第2のフィルタのそれぞれは、前記カラーフィルタの配列内の前記第3の方向及び前記第4の方向のフィルタライン内に1つ以上配置される請求項6から8のいずれか1項記載のカラー撮像素子。
- 前記基本配列パターン内では、前記第2の色の各色のうちの1色の前記第2のフィルタの各方向に、当該第2のフィルタとは異なる色の前記第2のフィルタまたは前記第1のフィルタが隣接して配置されている請求項1から5のいずれか1項記載のカラー撮像素子。
- 前記基本配列パターンは、前記第1のフィルタで構成される2×2画素に対応する正方配列を含む請求項10記載のカラー撮像素子。
- 前記第1の方向に対して式(1)で示されるθ°異なる方向を第5の方向としたときに、前記カラーフィルタの配列には、前記第2の色の各色のうちの1色の前記第2のフィルタを前記第5の方向に沿って等間隔で配置してなる斜めフィルタ配列が、前記第2の方向に沿って等間隔で配置されている請求項10または11記載のカラー撮像素子。
θ=tan-1(1/2)・・・式(1) - 前記カラーフィルタが正方形状である場合に、前記第3の方向及び第4の方向は前記第1の方向及び第2の方向に対してそれぞれ45°異なる請求項1から12のいずれか1項記載のカラー撮像素子。
- 前記第1の色は、緑及び透明のうち少なくともいずれかを含む請求項1から13のいずれか1項記載のカラー撮像素子。
- 前記第2の色は、赤と青を含む請求項1から14のいずれか1項記載のカラー撮像素子。
- 撮影光学系と、
前記撮影光学系を介して被写体像が結像するカラー撮像素子と、
前記結像した被写体像を示す画像データを生成する画像データ生成部とを備え、
前記カラー撮像素子は、請求項1から15のいずれか1項に記載のカラー撮像素子である、撮像装置。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201380036081.4A CN104429060B (zh) | 2012-07-06 | 2013-07-03 | 彩色摄像元件及摄像装置 |
JP2014523760A JP5698874B2 (ja) | 2012-07-06 | 2013-07-03 | カラー撮像素子及び撮像装置 |
US14/589,283 US9324749B2 (en) | 2012-07-06 | 2015-01-05 | Color imaging element and imaging device |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2012-152679 | 2012-07-06 | ||
JP2012152679 | 2012-07-06 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/589,283 Continuation US9324749B2 (en) | 2012-07-06 | 2015-01-05 | Color imaging element and imaging device |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2014007281A1 true WO2014007281A1 (ja) | 2014-01-09 |
Family
ID=49882033
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2013/068232 WO2014007281A1 (ja) | 2012-07-06 | 2013-07-03 | カラー撮像素子及び撮像装置 |
Country Status (4)
Country | Link |
---|---|
US (1) | US9324749B2 (ja) |
JP (1) | JP5698874B2 (ja) |
CN (1) | CN104429060B (ja) |
WO (1) | WO2014007281A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2017017692A (ja) * | 2015-06-29 | 2017-01-19 | オムニヴィジョン テクノロジーズ インコーポレイテッド | カラーエイリアシングを減少するためのカラーフィルタアレイパターン |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014007279A1 (ja) * | 2012-07-06 | 2014-01-09 | 富士フイルム株式会社 | カラー撮像素子および撮像装置 |
CN105516697B (zh) * | 2015-12-18 | 2018-04-17 | 广东欧珀移动通信有限公司 | 图像传感器、成像装置、移动终端及成像方法 |
US9928575B2 (en) * | 2016-03-01 | 2018-03-27 | Sony Corporation | Method and system for processing a multi-channel image |
WO2017149932A1 (ja) * | 2016-03-03 | 2017-09-08 | ソニー株式会社 | 医療用画像処理装置、システム、方法及びプログラム |
CN110326284B (zh) * | 2017-03-27 | 2021-11-30 | 株式会社尼康 | 摄像装置及摄像元件 |
WO2020244765A1 (en) * | 2019-06-06 | 2020-12-10 | Huawei Technologies Co., Ltd. | Color filter array apparatus |
CN111912392A (zh) * | 2019-12-09 | 2020-11-10 | 南开大学 | 一种基于轮转式滤光片的无人机用轻型光谱成像装置 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001085664A (ja) * | 1999-07-15 | 2001-03-30 | Sony Corp | 固体撮像素子およびその駆動方法並びにカメラシステム |
JP2003153291A (ja) * | 2001-11-08 | 2003-05-23 | Canon Inc | 撮像装置及びシステム |
JP2007184904A (ja) * | 2005-12-30 | 2007-07-19 | Internatl Business Mach Corp <Ibm> | ピクセル・アレイ、ピクセル・アレイを含むイメージング・センサ、及びイメージング・センサを含むデジタルカメラ |
JP2009027684A (ja) * | 2007-07-23 | 2009-02-05 | Visera Technologies Co Ltd | カラーフィルタアレイとそれを用いたイメージセンサ |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0823543A (ja) | 1994-07-07 | 1996-01-23 | Canon Inc | 撮像装置 |
EP0930789B1 (en) | 1998-01-20 | 2005-03-23 | Hewlett-Packard Company, A Delaware Corporation | Colour image pickup device |
JP4098438B2 (ja) | 1999-04-15 | 2008-06-11 | オリンパス株式会社 | カラー撮像素子及びカラー撮像装置 |
JP4385282B2 (ja) | 2003-10-31 | 2009-12-16 | ソニー株式会社 | 画像処理装置および画像処理方法 |
US8130236B2 (en) * | 2008-02-05 | 2012-03-06 | Aptina Imaging Corporation | Systems and methods to achieve preferred imager color reproduction |
JP4448888B2 (ja) * | 2008-04-01 | 2010-04-14 | 富士フイルム株式会社 | 撮像装置及び撮像装置の信号処理方法 |
US20110013056A1 (en) * | 2009-07-17 | 2011-01-20 | Searete Llc, A Limited Liability Corporation Of The State Of Delaware | Color filters and demosaicing techniques for digital imaging |
JP5471117B2 (ja) * | 2009-07-24 | 2014-04-16 | ソニー株式会社 | 固体撮像装置とその製造方法並びにカメラ |
JP2011199798A (ja) * | 2010-03-24 | 2011-10-06 | Sony Corp | 物理情報取得装置、固体撮像装置、物理情報取得方法 |
JP5044673B2 (ja) * | 2010-03-25 | 2012-10-10 | 株式会社東芝 | 固体撮像装置および画像記録装置 |
WO2012114993A1 (ja) * | 2011-02-21 | 2012-08-30 | 富士フイルム株式会社 | カラー撮像素子 |
-
2013
- 2013-07-03 WO PCT/JP2013/068232 patent/WO2014007281A1/ja active Application Filing
- 2013-07-03 CN CN201380036081.4A patent/CN104429060B/zh not_active Expired - Fee Related
- 2013-07-03 JP JP2014523760A patent/JP5698874B2/ja not_active Expired - Fee Related
-
2015
- 2015-01-05 US US14/589,283 patent/US9324749B2/en not_active Expired - Fee Related
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001085664A (ja) * | 1999-07-15 | 2001-03-30 | Sony Corp | 固体撮像素子およびその駆動方法並びにカメラシステム |
JP2003153291A (ja) * | 2001-11-08 | 2003-05-23 | Canon Inc | 撮像装置及びシステム |
JP2007184904A (ja) * | 2005-12-30 | 2007-07-19 | Internatl Business Mach Corp <Ibm> | ピクセル・アレイ、ピクセル・アレイを含むイメージング・センサ、及びイメージング・センサを含むデジタルカメラ |
JP2009027684A (ja) * | 2007-07-23 | 2009-02-05 | Visera Technologies Co Ltd | カラーフィルタアレイとそれを用いたイメージセンサ |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2017017692A (ja) * | 2015-06-29 | 2017-01-19 | オムニヴィジョン テクノロジーズ インコーポレイテッド | カラーエイリアシングを減少するためのカラーフィルタアレイパターン |
Also Published As
Publication number | Publication date |
---|---|
CN104429060A (zh) | 2015-03-18 |
CN104429060B (zh) | 2016-04-20 |
US20150109493A1 (en) | 2015-04-23 |
JP5698874B2 (ja) | 2015-04-08 |
JPWO2014007281A1 (ja) | 2016-06-02 |
US9324749B2 (en) | 2016-04-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5702894B2 (ja) | カラー撮像素子および撮像装置 | |
JP5702896B2 (ja) | カラー撮像素子及び撮像装置 | |
JP5927068B2 (ja) | カラー撮像素子 | |
JP5698874B2 (ja) | カラー撮像素子及び撮像装置 | |
JP5702893B2 (ja) | カラー撮像素子および撮像装置 | |
JP5698875B2 (ja) | カラー撮像素子および撮像装置 | |
JP5698873B2 (ja) | カラー撮像素子および撮像装置 | |
JP5702895B2 (ja) | カラー撮像素子および撮像装置 | |
US9185375B2 (en) | Color imaging element and imaging device | |
US20140307135A1 (en) | Color imaging element | |
US8976275B2 (en) | Color imaging element |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: 201380036081.4 Country of ref document: CN |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 13812554 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2014523760 Country of ref document: JP Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 13812554 Country of ref document: EP Kind code of ref document: A1 |