CN102158632B - Method and device for capturing CFA (color filter array) - Google Patents

Abstract

The invention discloses a method for capturing a CFA (color filter array), which is used for realizing the better de-embedding property of CFA and avoiding the color cast problem in the imaging process. The method comprises the following steps: selecting a CFA base mode, wherein the corresponding CFA of the selected CFA base mode contains panchromatic pixel and two-color pixel; choosing pixel points, the number of which is less than a preset value, from the corresponding CFA of the selected CFA base mode; and replacing the color of the selected pixel points by the using of a third color different from the two colors, thereby acquiring the CFA. The invention also discloses a device which is used for realizing the method.

Description

A method and device for obtaining CFA

technical field

The invention relates to the fields of optics and computers, in particular to a method and device for obtaining CFA.

Background technique

In order to reduce the registration error between cost, volume and color, static color image acquisition devices, such as CCD (Charge-coupled Device, charge-coupled device) still image digital cameras, usually have CFA (Color Filter Array, color filter array) monolithic sensor. At each pixel of the image, the sensor can only collect one color, and interpolation is required to obtain the values of the three primary colors at each pixel. The interpolation process of this image is a demosaicking process. Except for some random CFAs, 2D CFAs are generally realized by periodically repeating a minimal CFA pattern covering the entire image sensor array surface. The structures and performances of CFA obtained by combining different minimum CFA modes are different. Therefore, a minimum CFA mode (hereinafter referred to as CFA mode) also expresses the characteristics of the CFA obtained by combining the minimum CFA modes. The design and selection of CFA modes and demosaicing methods are crucial for the imaging of color images.

The most widely used CFA mode at present is the Bayer (Bayer) CFA mode, which uses 1/2 green, 1/4 red and 1/4 blue modes. Although the Bayer CFA mode has better demosaicing performance, and the software cost required for demosaicing is lower, it does not contain panchromatic pixels, so the photosensitive performance is not good. In order to obtain CFA with high photosensitive performance, some new CFA modes have emerged, such as the CFA mode of CFA2.0. These high-sensitivity CFA modes that contain panchromatic pixels have some significant disadvantages: these CFA modes have poor demosaic performance because of their unreasonable structure, or contain too many colors, or contain colors that are not three primary colors , the complexity of demosaicing is high, or the cost of hardware implementation is high. However, if the CFA mode uses only two colors in addition to panchromatic pixels, the image obtained after demosaicing may have a color cast, which seriously affects the imaging quality of the camera.

Contents of the invention

Embodiments of the present invention provide a method and device for obtaining CFA, which are used to achieve higher photosensitivity and better demosaicing performance of CFA, and can avoid color cast problems in the image forming process as much as possible.

A method for obtaining a color filter array CFA, comprising the following steps:

A periodic CFA pattern is selected as the CFA base pattern, wherein the CFA corresponding to the selected CFA base pattern includes panchromatic pixels and pixels of two colors, and the two colors are the three primary colors of red, green, and blue Any two colors in or any two colors in the three primary complementary colors cyan, magenta and yellow;

In the CFA corresponding to the selected CFA-based pattern, select a number of pixels not exceeding 2%, wherein the selected pixels are randomly selected pixels in the CFA whose number does not exceed the 2%; Or select the pixel points whose number does not exceed the 2% in a pseudo-random manner in the CFA; or select the pixel points in a non-random manner in the CFA that do not exceed the 2% number;

Replace the color at the selected pixel point with a third color other than the two colors to obtain a CFA, wherein the color of the selected pixel point is a panchromatic pixel or a pixel of two colors, and the The third color is a color other than the two colors in the three primary colors or a color other than the two colors in the complementary colors of the three primary colors.

An imaging method, comprising the steps of:

Carry out imaging with the image sensor that has CFA as claimed in claim 1, and obtain CFA image;

Demosaicing the CFA image;

Comparing the existing color values at all pixel points in the CFA image with the value of the color obtained after demosaicing, when the comparison results are inconsistent, according to all existing color values of the CFA image, the entire The color of the image is corrected.

A CFA acquisition device, comprising:

The selection module is used to select a periodic CFA pattern as the CFA base pattern, wherein the CFA corresponding to the selected CFA base pattern includes panchromatic pixels and pixels of two colors, and the two colors are red, Any two colors of the three primary colors of green and blue or any two colors of the three complementary colors of cyan, magenta, and yellow, and the number of pixels selected in the CFA corresponding to the selected CFA base mode does not exceed 2% points, wherein, the selected pixel points are randomly selected pixels whose number does not exceed the 2% in the CFA; or pseudo-randomly selected pixels whose number does not exceed the 2% in the CFA Pixels; or non-randomly selecting pixels in the CFA whose number does not exceed the 2%;

A processing module, configured to replace the color at the selected pixel point with a third color other than the two colors to obtain a CFA, wherein the color of the selected pixel point is a panchromatic pixel or two colors Pixels of different colors, the third color is a color other than the two colors in the three primary colors or a color other than the two colors in the complementary colors of the three primary colors.

An imaging device comprising:

The acquisition module is used for imaging with the image sensor with the CFA as claimed in claim 1, and obtains the CFA image;

An operation module, configured to demosaick the CFA image;

A correction module, configured to compare the existing color values at all pixel points in the CFA image with the value of the color obtained after demosaicing, and when the comparison results are inconsistent, according to all existing color values of the CFA image The color of the entire image after demosaicing is corrected.

A kind of CFA, described CFA is generated according to the method as claimed in claim 1, and described CFA comprises:

Panchromatic pixels, two-color pixels, and third color pixels other than said panchromatic pixels and two-color pixels;

The proportion of panchromatic pixels is about 1/2 or more, and the proportions of other two colors are about 1/4 or less;

The number of pixels occupied by the third color does not exceed a set value;

The two colors are any two colors in the three primary colors or the three primary colors of complementary colors, and the third color is a color other than the two colors in the three primary colors or the three primary colors of complementary colors;

Wherein, the panchromatic pixel filter or the two-color filter is replaced by using the third filter.

The embodiment of the present invention selects the CFA base mode, wherein, the CFA corresponding to the CFA base mode includes panchromatic pixels and pixels of two colors; selects pixels whose number does not exceed the set value in the CFA; A third color other than the two colors replaces the color at the selected pixel to obtain the desired CFA. Because there are panchromatic pixels in CFA, the photosensitivity of CFA is better; because there are at least two color pixels in CFA in addition to panchromatic pixels, color images can be obtained; because the proportion of the third color does not exceed the set Therefore, it can be considered that the demosaicing performance of the selected CFA with good demosaicing performance is still good, and the complexity of its demosaicing is small; in the CFA, select the number of pixels that do not exceed the set value, and use the first Three colors replace the color at the selected pixel, and this third color can be used as a color reference to calibrate and correct color casts that occur during image formation.

Description of drawings

Fig. 1 is the main flowchart of the acquisition method of CFA in the embodiment of the present invention;

Fig. 2 is the main flowchart of the imaging method in the embodiment of the present invention;

FIG. 3A is a detailed flowchart of a method for obtaining CFA in an embodiment of the present invention;

3B is a detailed flowchart of the imaging method in the embodiment of the present invention;

Fig. 4 is the main structural diagram of the acquisition device of CFA in the embodiment of the present invention;

Fig. 5 A is the schematic diagram of LRLB CFA base model in the embodiment of the present invention;

Figure 5B is a schematic diagram of the MWY CFA base mode in an embodiment of the present invention;

Figure 5C is a schematic diagram of a general two-color CFA-based mode in an embodiment of the present invention;

FIG. 6A is a schematic diagram of a part of the CFA after replacing the color at the selected pixel with a third color in an embodiment of the present invention;

FIG. 6B is a schematic diagram of the CFA part after replacing the color at the selected pixel point with a third color in the embodiment of the present invention;

FIG. 6C is a schematic diagram of a part of the CFA after replacing the color at the selected pixel with a third color in an embodiment of the present invention;

FIG. 7 is a main structural diagram of an imaging device in an embodiment of the present invention.

Detailed ways

The embodiment of the present invention selects the CFA base mode, wherein the CFA corresponding to the CFA base mode includes panchromatic pixels and two-color pixels; selects pixels whose number does not exceed the set value in the CFA; Replace the color at the selected pixel with a third color other than the above two colors to obtain the desired CFA. Panchromatic refers to the color that contains all the visible spectrum, that is, the mixed color of all colors, while color refers to the color that only contains part of the spectrum. Because there are panchromatic pixels in the CFA, the photosensitive performance of the CFA is better; because the proportion of the third color does not exceed the set value, it can be considered that the good demosaicing performance of the selected CFA can be maintained, and the demosaicing performance Less complex; select pixels whose number does not exceed the set value in the CFA, replace the color at the selected pixel with a third color, this third color can be used as a color reference to calibrate and correct the image Color cast that occurs during imaging.

The following describes how to obtain CFA through specific procedures.

Referring to Fig. 1, the main method flow of CFA acquisition in the embodiment of the present invention is as follows:

Step 101: Select a CFA-based pattern, wherein the CFA-based pattern includes panchromatic pixels and two-color pixels. Since the CFA is obtained by periodically covering the entire surface of the image sensor array with a CFA pattern, it is only necessary to select a CFA pattern with good performance when selecting a CFA base pattern. Preferably, it includes no less than 1/2 panchromatic pixels.

Step 102: Select pixels whose number does not exceed a set value in the CFA corresponding to the CFA base pattern. This setting value may be 2%, that is, the number of pixels selected in one CFA is preferably not more than 2% of the total number of pixels in this CFA. Among them, in CFA, each pixel is a panchromatic filter that does not filter visible light or a monochromatic filter. Because changing the color in the CFA with good demosaicing performance will complicate the structure of CFA, and its demosaicing performance will also deteriorate, and the number of changed pixels is within the range of the set value, making the added third color The number of pixels is small, so it will basically not affect the original demosaicking performance of CFA. Wherein, the selection method of the changed pixels may be random selection, pseudo-random selection, or non-random selection. Among them, non-random methods include quota method, formula calculation method and judgment method, etc., which mainly refer to artificial selection. The colors of the selected pixels can be the same color, different colors, or full-color pixels.

Step 103: Replace the color at the selected pixel with a third color other than the panchromatic pixel and the two colors. Among them, the third color is a color different from the two colors in the determined CFA-based pattern, and this third color can be selected arbitrarily, but in order to ensure demosaicing performance and reduce costs, this third color is the best Select a color other than the original two colors in the CFA among the three primary colors of red, green, and blue or a color other than the two original colors in the CFA among the three complementary colors cyan, magenta, and yellow.

Referring to Fig. 2, the main method flow of imaging in the embodiment of the present invention is as follows:

Step 201: Imaging with an image sensor with the CFA, and obtaining a CFA image.

Step 202: Demosaicking the CFA image. The obtained CFA image is demosaiced with a demosaic algorithm.

Step 203: Using the existing panchromatic pixel values and three color values in the CFA image to calibrate and correct the three color values obtained after de-mosaicing at each pixel. For an image with no or less color cast. For example, the selected CFA base mode is LRLB CFA mode, in which, for example, the color at a certain pixel point is red, after demosaicing, the color at this pixel point can be represented by three primary colors of red, green, and blue. Because there are two colors of red and blue in the LRLB CFA model, by comparing the existing red with the red after demosaicing, and comparing the existing blue with the blue after demosaicing, you can It is known whether there is a color cast in the red and blue obtained after demosaicing, and, in the embodiment of the present invention, the color at the selected pixel point is replaced by a third color other than the full-color pixel and two colors , preferably, the third color can be green, and then this green can be compared with the green obtained after demosaicing to determine whether there is a color cast in the green obtained after demosaicing.

Referring to Figure 3A, the detailed method flow for obtaining CFA in the embodiment of the present invention is as follows:

Step 3001: Select a CFA base model. Selecting the CFA mode can be achieved by selecting the CFA base mode. For example, the selected CFA base mode is LRLB CFA mode.

Step 3002: Select pixels whose number does not exceed the set value in the CFA corresponding to the LRLB CFA base mode. For example, the set value is 2%.

Step 3003: Replace the color at the selected pixel point with a third color in the selected CFA except the panchromatic pixel and the two colors. For example, the third color is green.

Referring to FIG. 3B, the detailed method flow of imaging in the embodiment of the present invention is as follows:

Step 3101: Imaging with the image sensor with the CFA to obtain a CFA image.

Step 3102: Demosaic the CFA image.

Step 3103: Compare the existing red, green, and blue color values in the CFA image with the red, green, and blue color values obtained after de-mosaicing at a pixel, and judge whether they are consistent. When the judgment result is no, go to step 307 , otherwise go to step 308 . Compare the existing red, green, and blue color values in the CFA image with the red, green, and blue color values obtained after demosaicing. The comparison process can be: each color has a value, and the value of this color can be obtained according to the color. For example, red is compared to determine whether the red value obtained after demosaicing is consistent with the existing red value in the CFA image.

Step 3104: Correct the color value that produces color cast. For example, if the red value obtained at a pixel point after demosaicing is inconsistent with the existing red value in the CFA image, it is determined that the red color obtained after demosaicing at this pixel point has a color cast phenomenon, which can be based on the CFA image The existing red value is corrected to the red value obtained after demosaicing to minimize the error between these two values. Preferably, the red value obtained after demosaicking at the pixel can be corrected to be the same as the existing red value in the CFA.

Step 3105: Determine whether there are pixels that have not been compared. When the judgment result is yes, continue to step 3103, otherwise end the process. Make sure all pixels are aligned and corrected to get a higher quality image.

Referring to FIG. 4 , the apparatus for obtaining CFA in the embodiment of the present invention includes a selection module 401 and a processing module 402 .

The selection module 401 is used to select a CFA-based mode, wherein the CFA corresponding to the selected CFA-based mode includes panchromatic pixels and two-color pixels, and selects from the CFA corresponding to the selected CFA-based mode The number of pixels does not exceed the set value. The selected CFA base pattern can be the LRLB CFA pattern shown in Figure 5A, which includes 1/2 panchromatic pixels, where W represents panchromatic pixels, R represents red pixels, B represents blue pixels, or The MWY CFA mode shown in 5B includes 1/2 panchromatic pixels, wherein W represents panchromatic pixels, M represents magenta pixels, and Y represents yellow pixels, or the selected CFA base mode can be expressed as The general two-color CFA mode shown in FIG. 5C , wherein W represents a full-color pixel, F represents a first color pixel, and S represents a second color pixel, and F and S need to be different colors. Preferably, in order to reduce the complexity of demosaicing, in the embodiment of the present invention, F and S are any two of the three primary colors, for example, F and S are red and blue, or F and S are red and green, or F and S are blue and green etc. Preferably, the proportion of the first color F and the second color S can be no more than 1/4, so as to achieve the best effect. After the CFA-based mode is selected, the selection module 401 continues to select pixels whose number does not exceed the set value in the CFA corresponding to the CFA-based mode. The selection module 401 can record the selected result, so as to ensure that the color of which pixels have changed during demosaicing.

The processing module 402 is used to replace the color at the selected pixel point with a third color other than the panchromatic pixel and the two colors to obtain the required CFA. After the selection module 401 selects pixels whose number does not exceed the set value in the determined CFA, the processing module 402 replaces the color at the pixels selected by the selection module 401 with a third color. For example, if the selected CFA base pattern is the WFS pattern, the CFA pattern corresponding to the replaced CFA may be as shown in FIG. 6A , FIG. 6B or FIG. 6C , or may be in other forms. Wherein, W represents a full-color pixel, F and S represent the first color and the second color respectively, T represents the third color used by the processing module 402 to replace a certain color, and the position of T can be randomly selected or can be Select by pseudo-random method, or select by non-random method, the number of T is not more than the set value. In the embodiments of the present invention, the replacement of the color at a pixel point in a CFA corresponding to the CFA base pattern is taken as an example.

After the CFA is obtained by the CFA obtaining device in the embodiment of the present invention, the imaging operation can be continued according to the obtained CFA, so as to obtain an image with higher sensitivity and less color cast.

Referring to FIG. 7 , an embodiment of the present invention also provides an imaging device, which may include an acquisition module 403 , an operation module 404 and a correction module 405 . The device is used for imaging according to the CFA acquired by the CFA acquisition device, so as to obtain an image with no color cast or less color cast.

The acquiring module 403 is configured to use the image sensor with the CFA to perform imaging to obtain a CFA image.

The operation module 404 is used for demosaicing the CFA image. The operation module 404 is used for demosaicking the obtained CFA image with a demosaicing algorithm. Wherein, demosaicing may be performed on each pixel separately, or all pixels may be demosaiced simultaneously, so as to obtain three primary colors at each pixel.

The correction module 405 is used for calibrating and correcting the three colors obtained after demosaicking at each pixel by using the existing panchromatic pixel values and three color pixel values in the CFA image. If the correction module 405 compares and determines that the color obtained after demosaicing has a color cast phenomenon, the color obtained after demosaicing is corrected according to the existing panchromatic pixel values and three color pixel values in the CFA image, so that they The error between them is the smallest. During the demosaicing process, since the CFA base pattern selected by the selection module 401 has two colors except panchromatic pixels, when demosaicing, the energy of one color obtained at each pixel point is restored to three primary color values. That is, no matter which CFA base mode is selected, no matter which color is used at a pixel point, after demosaicing, the color obtained at each pixel point is represented by the three primary colors of red, green, and blue. The correction module 405 can acquire the value of the color according to the color. If the selected CFA base mode is the MWYCFA mode, then the selection module 401 can select cyan as the third color. After the CFA image corresponding to the MWY CFA base mode is de-mosaiced, the color at each pixel can also be changed from red, green, blue three primary colors, and magenta, yellow and cyan are the complementary colors of the three primary colors, and can be interchanged without deviation between the three primary colors. The correction module 405 can convert the existing magenta, yellow and cyan into Three primary colors, and then compare and correct the color obtained at each pixel point after demosaicing with the converted color without affecting the comparison result.

The embodiment of the present invention selects the CFA base mode, wherein the CFA corresponding to the CFA base mode includes panchromatic pixels and two-color pixels; selects pixels whose number does not exceed the set value in the CFA; Replace the color at the selected pixel with a third color other than the above two colors to obtain the desired CFA. Because there are panchromatic pixels in the CFA, the photosensitivity of the CFA is better; because the proportion of the third color does not exceed the set value, it can be considered that the complexity of the demosaicing of the selected CFA is small; in the CFA Select the number of pixels that do not exceed the set value, and replace the color at the selected pixel with the third color, because each pixel is obtained after demosaicing is three primary colors, and after adding the third color CFA also has three colors. Therefore, in the imaging process, these three colors can be used as references to calibrate and correct the colors obtained after demosaicing, so as to avoid color cast and affect the performance of the camera. Higher, better quality images with less color cast. In the selected CFA base mode, the three colors except panchromatic pixels can be three primary colors, so the complexity of demosaicing is small; and only a third color is used to replace a certain color within the set value range, and in the solution The third color can be ignored during the mosaic process, and basically does not affect the demosaic performance of CFA.

Those skilled in the art should understand that the embodiments of the present invention may be provided as methods, systems, or computer program products. Accordingly, the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and combinations of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a Means for realizing the functions specified in one or more steps of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart flow or flows and/or block diagram block or blocks.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (9)

1. the acquisition methods of a color filtering array CFA is characterized in that, may further comprise the steps:

Selected one-period property CFA pattern is as CFA basic mode formula, wherein, comprise panchromatic pixels and two kinds of color pixel among described selected CFA basic mode formula and the corresponding CFA, described two kinds of colors are any two kinds of colors in any two kinds of colors in the red, green, blue three primary colors or three primary colors complementary color green grass or young crops, magenta, the yellow;

Select quantity to be no more than 2% pixel in the CFA of described selected CFA basic mode formula correspondence, wherein, the pixel of described selection is for to select quantity to be no more than described 2% pixel in described CFA at random; Perhaps in described CFA, to select quantity to be no more than described 2% pixel in pseudorandom mode; Perhaps in described CFA, to select quantity to be no more than described 2% pixel in nonrandom mode;

The color of replacing the pixel place of described selection with the third color except described two kinds of colors, obtain CFA, wherein, the color of selected pixel is panchromatic pixels or two kinds of color pixel, and described the third color is the color except described two kinds of colors in the color except described two kinds of colors or the three primary colors complementary color in the three primary colors.

2. the method for claim 1 is characterized in that, the shared ratio of panchromatic pixels among the CFA of described CFA basic mode formula and correspondence is not less than 1/2; Two kinds of shared ratios of color all are not more than 1/4.

3. a formation method is characterized in that, may further comprise the steps:

Carry out imaging with the imageing sensor that has CFA as claimed in claim 1, and obtain the CFA image;

The CFA image is carried out solution to be inlayed;

The existing color value in all pixel places in the described CFA image is conciliate the value of inlaying this color that the back obtains compare, when comparison result was inconsistent, the color of the entire image after according to the existing all colours value of CFA image solution being inlayed was revised.

4. method as claimed in claim 3 is characterized in that, the CFA that described CFA obtains for the acquisition methods according to CFA.

5. the deriving means of a CFA is characterized in that, comprising:

Select module, be used for selected one-period property CFA pattern as CFA basic mode formula, wherein, comprise panchromatic pixels and two kinds of color pixel among the CFA of described selected CFA basic mode formula correspondence, described two kinds of colors are any two kinds of colors in any two kinds of colors in the red, green, blue three primary colors or three primary colors complementary color green grass or young crops, magenta, the yellow, and in the CFA of described selected CFA basic mode formula correspondence, select quantity to be no more than 2% pixel, wherein, the pixel of described selection is for to select quantity to be no more than described 2% pixel in described CFA at random; Perhaps in described CFA, to select quantity to be no more than described 2% pixel in pseudorandom mode; Perhaps in described CFA, to select quantity to be no more than described 2% pixel in nonrandom mode;

Processing module, be used for the color that the third color except described two kinds of colors is replaced the pixel place of described selection, obtain CFA, wherein, the color of the pixel of described selection is panchromatic pixels or two kinds of color pixel, and described the third color is the color except described two kinds of colors in the color except described two kinds of colors or the three primary colors complementary color in the three primary colors.

6. device as claimed in claim 5 is characterized in that, the shared ratio of panchromatic pixels among the CFA of described CFA basic mode formula correspondence is not less than 1/2; The shared ratio of other two kinds of color pixel all is not more than 1/4.

7. an imaging device is characterized in that, comprising:

Acquisition module carries out imaging with the imageing sensor that has CFA as claimed in claim 1, and obtains the CFA image;

Operational module is used for that described CFA image is carried out solution and inlays;

Correction module, be used for the value that this color of back acquisition is inlayed in the existing color value reconciliation in all pixel places of described CFA image is compared, when comparison result was inconsistent, the color of the entire image after according to the existing all colours value of CFA image solution being inlayed was revised.

8. device as claimed in claim 7 is characterized in that, the CFA that described CFA obtains for the acquisition methods according to CFA.

9. CFA, described CFA generates according to method according to claim 1, it is characterized in that described CFA comprises:

The filter disc of panchromatic pixels filter disc, two kinds of colors and the third color filter disc except described panchromatic pixels filter disc and two kinds of color filter discs;

The shared ratio of panchromatic pixels filter disc is not less than 1/2, and the shared ratio of other two kinds of color filter discs all is not more than 1/4;

The quantity of the pixel that described the third color filter disc is shared is no more than set point;

Described two kinds of colors are any two kinds of colors in three primary colors or the three primary colors complementary color, and the third color is the color except described two kinds of colors in three primary colors or the three primary colors complementary color;

Wherein, by using described the third filter disc to replace the filter disc of panchromatic pixels filter disc or two kinds of colors.

Images