CN101478687B - Correcting method for pseudo color pixel in digital image - Google Patents

Abstract

The present invention discloses a method for correcting pseudo color pixel in digital image. The method is used for correcting the pseudo color pixel which is generated after a color correction array processing. The method comprises the following steps: obtaining an original image, generating processed image after the color correction array processing; comparing the pixel of original image and the pixel of processed image according to color diversity factor for finding out the pseudo color pixel in the processed image; executing color correction processing to the original image and the pseudo color pixel at the corresponding position of processed image, and correcting the pseudo color pixel according to the pixel color at the corresponding position of original image.

Description

Bearing calibration to pseudo color pixel in the digital picture

Technical field

The invention discloses a kind of processing method of digital picture, relate in particular to a kind of color calibration method the pseudo color pixel in the digital picture.

Background technology

Human eye is to the identification of color, is based on human eye there are three kinds of different sensing units in light, and different sensing units has the principle of different response curves to the light of different-waveband, by the synthetic perception that obtains color of brain.In general, the notion with red green blue tricolor that we can be popular is understood the decomposition of color and is synthesized.

The photosensory assembly of digital camera and human eye are not identical for the response of RGB light.Since photosensory assembly to the response of spectrum, with normally devious to the response of spectrum with human eye on each component of RGB light, just need be proofreaied and correct it certainly.Not only on cross effect, the response intensity to each component of color also needs to proofread and correct equally.Common way is by a colour correction array (colorcorrection matrix, C M) color once to be proofreaied and correct.

For the handling process of color correction array, please refer to shown in Figure 1.At first, set one group of color correction array (step S110).The size of color correction array can be one group of 3*3 pel array or 4*3 pel array.Wherein pixel array sized determines according to the Processing Algorithm that is determined.The color correction array overlapped respectively be used for digital picture, make the color correction array respectively and nonoverlapping applying mechanically digital picture (step S120).Please refer to shown in the formula 1, it is to color correction array expression formula.

$\left[\begin{array}{c}{R}^{\′}\\ G^{\′}\\ B^{\′}\end{array}\right]=\left[\begin{array}{ccc}{\mathrm{CCM}}_{11}& {\mathrm{CCM}}_{12}& {\mathrm{CCM}}_{13}\\ {\mathrm{CCM}}_{21}& {\mathrm{CCM}}_{22}& {\mathrm{CCM}}_{23}\\ {\mathrm{CCM}}_{31}& {\mathrm{CCM}}_{32}& {\mathrm{CCM}}_{33}\end{array}\right]*\left[\begin{array}{c}R\\ G\\ B\end{array}\right]$ Formula 1

R is a red pixel; G is a green pixel; B is a blue pixel; CCM _MnBe respectively the color correction parameter, wherein m is that n is the position of being expert in the position of row; R ' is through the red pixel behind the color correction; G ' is through the green pixel behind the color correction; B ' is through the blue pixel behind the color correction.Please refer to Fig. 2 a and Fig. 2 b, it is respectively the schematic diagram of digital picture through the color correction ARRAY PROCESSING.Original image 200 in Fig. 2 a, what each little square was represented is a pixel 220 (pixel).Color correction array 210 is the square of frame of broken lines line, is assumed to be the 3*3 pixel size at this.Also be subdivided into the pixel of three different colours in Fig. 2 b for original image 200 each pixel 220, it is respectively red pixel 221, green pixel 222 and blue pixel 223.

At last according to above-mentioned operation result, produce the pixel value schematic diagram behind the color correction of Fig. 2 c.Oblique line square in handling image 300 is a pseudo color pixel 230.But digital picture is through after the color correction process, though can improve the color saturation of having handled image 300.But may in the thin portion of image, occur with actual scenery originally in and non-existent color dot or color lump.

For also utilizing methods such as gaussian filtering or low-pass filtering, the processing of removing false colour in the known technology.But the method for these filtering is the actions of removing for the pixel of whole digital pictures, though can remove false colour like this.But also can cause other color of pixel deviation simultaneously.

Summary of the invention

The object of the present invention is to provide a kind of the corresponding color calibration method of pseudo color pixel to be appearred in digital picture, the pseudo color pixel that is occurred in the digital picture is carried out treatment for correcting.

To achieve these goals, the invention provides a kind of bearing calibration to pseudo color pixel in the digital picture, it is in order to proofread and correct the pseudo color pixel through being produced after the color correction ARRAY PROCESSING, comprise the following steps: to obtain an original image, make and utilize a color correction array that this original image is carried out color correction process, handled image in order to generate one; Handle pixel between image according to a color distortion degree in order to contrast this original image and this, found out the pseudo color pixel in this pixel of having handled image; And this original image and this this pseudo color pixel of having handled the relevant position of image carried out color correction process according to following formula:

Pixel _img3＝m*Pixel _img1+n*Pixel _img2

Wherein, Pixel _Img1Pixel for this original image; Pixel _Img2For this has handled the pixel of image; Pixel _Img3It is an output pixel; M+n=1, m 〉=0, n 〉=0; M value and n value are searched according to a look-up table and are obtained, and the m value is corresponding to this original image, and the n value has been handled image corresponding to this.

The invention provides a kind of treatment for correcting of the pseudo color pixel to digital picture.In order to the digital picture that produces pseudo color pixel after the process color correction ARRAY PROCESSING is carried out the correction of pseudo color pixel.Its pixel color according to the relevant position of original image is proofreaied and correct pseudo color pixel.After overcorrect, make this color of pixel can be more near the pixel color of original image.And can not have influence on other color of pixel of digital picture.

Describe the present invention below in conjunction with the drawings and specific embodiments, but not as a limitation of the invention.

Description of drawings

Fig. 1 is the configuration diagram of known technology;

Fig. 2 a is the schematic diagram of the digital picture of known technology through the color correction ARRAY PROCESSING;

Fig. 2 b is the schematic diagram of the digital picture of known technology through the color correction ARRAY PROCESSING;

Fig. 2 c is the pixel value schematic diagram behind the color correction of known technology;

Fig. 3 is a false colour correcting process schematic diagram of the present invention;

Fig. 4 is the correction schematic diagram of the present invention to pseudo color pixel;

Fig. 5 searches and the distribution of color curve chart for distribution of color.

Wherein, Reference numeral:

200 original images

210 color correction arrays

220 pixels

221 red pixels

222 green pixels

223 blue pixel

230 pseudo color pixels

300 handle image

410 original images

411 red pixels

412 green pixels

413 blue pixel

420 have handled image

421 red pixels

422 green pixels

423 blue pixel

430 display pixels

The red pixel of 431 output images

The green pixel of 432 output images

The blue pixel of 433 output images

Embodiment

The present invention utilizes calculator that the digital picture that produces false colour is carried out its treatment for correcting.Please refer to shown in Figure 3ly, it is a false colour correcting process schematic diagram of the present invention.False colour bearing calibration proposed by the invention comprises the following steps: to obtain original image, generates after making it via the color correction array operation and has handled image (step S310).Original image refers to untreated digital picture.Then, utilize the color correction array to carry out color correction process original image, and then image has been handled in generation accordingly.

Next, according to color distortion degree contrast original image and handled pixel between image, find out the pseudo color pixel (step S320) in the pixel of handling image.The image difference contrast is the array that utilizes an x*y pixel size, in order to inspect the appearance whether pseudo color pixel is arranged in each array in the digital picture respectively.

With original image with handle image and contrast the wherein color distortion degree of each pixel value of relevant position respectively.Carry out the contrast of color distortion degree with the red green blue tricolor value of graphic color colour gamut in the present embodiment.Except above-mentioned graphic color colour gamut, also can utilize television system color colour gamut (YCbCrcolor filed) to carry out the foundation of color distortion degree contrast.Original image is with the pixel difference of the relevant position of having handled image when excessive, and then this pixel is arranged is pseudo color pixel in representative.

Original image and the pseudo color pixel of handling the relevant position of image are carried out color correction process (step S330) according to formula 2:

Pixel _Img3=m*Pixel _Img1+ n*Pixel _Img2Formula 2

Wherein, Pixel _Img1Pixel for original image; Pixel _Img2For handling the pixel of image; Pixel _Img3It is an output pixel; M+n=1, m 〉=0, n 〉=0.It should be noted that Pixel except being the single pixel value, also can be used for each color pixel values.

Please refer to shown in Figure 4, the schematic diagram that it is proofreaied and correct pseudo color pixel for the present invention.To handle and occur pseudo color pixel 420 in the image, and from original image, choose the pixel 410 of same position according to its position and come out.And the color component of the pixel 410 of original image and the color component of pseudo color pixel 420 carried out color correction.At last, resulting each color component is reintegrated into the display pixel 430 of output image.The color component of the pixel 410 of original image is respectively red pixel 411, green pixel 412 and blue pixel 413; The color component of pseudo color pixel 420 is respectively red pixel 421, green pixel 422 and blue pixel 423; The color component of the display pixel 430 of output image is respectively red pixel 431, green pixel 432 and blue pixel 433.

Color correction process is according to a distribution of color look-up table, find out the m value and the corresponding n value of having handled image of corresponding original image, according to original image and handled pixel color diversity factor between the image, find out the m value and the corresponding n value of having handled image of corresponding original image.The total amount of m value and n value is 1, and its represented meaning is for to carry out the mediation of a ratio with the pixel and the pseudo color pixel value of original image.So because each color component to thinking to show that not being is equivalent, if give identical adjusted value with each color component, can allow the color distortion after proofreading and correct bigger.Please refer to shown in Figure 5ly, it is distribution of color look-up table and distribution of color curve synoptic diagram.

Because directly the color of pseudo color pixel is changed into the color of the respective pixel of original image, the color distortion between the pixel arround making easily is excessive, causes visually significantly lofty.So the present invention utilizes original image and the pixel of handling the image relevant position, two kinds of colors are found out corresponding ratio according to above-mentioned mode mix, so as to mixing and similar on every side color.

Further, can carry out the processing of formula 2 at the demonstration component of the demonstration colour gamut of pseudo color pixel 420.Utilize the red green blue tricolor value of graphic color colour gamut to carry out the contrast of color distortion degree.Its processing procedure comprises the following steps: that also the pseudo color pixel that will handle image generates corresponding red pixel 421, green pixel 422 and blue pixel 423.Respectively the red pixel 421 of pseudo color pixel and the red pixel 411 of original image are carried out color correction process; The green pixel 422 of pseudo color pixel and the green pixel 412 of original image are carried out color correction process; The blue pixel 423 of pseudo color pixel is carried out color correction process with the blue pixel 413 of original image.

Utilizing the red pixel 421 of adjusting pseudo color pixel at this is example.Red pixel 411 values of supposing the pixel in the original image are 100, and red pixel 421 values that produce pseudo color pixel are 150.Search the distribution of color look-up table,, from the table of comparisons, find out corresponding m value and n value in order to the color of finding out its original image and the difference ratio of pseudo color pixel value.Simple, because the red value of false colour is bigger than the red value of original image, can be bigger so adjust the m value of original image than the n value.Suppose that the m value that is found is 0.7, then the n value is 0.3.Calculate output pixel value in foundation formula 2, the result who obtains at last is for shown in the following formula:

0.7*100+0.3*150=115 formula 3

If the demonstration component with television system color colour gamut carries out the processing of formula 2, then carry out the following step: the pixel that will handle image generates corresponding luminance component, chroma blue component and red color component; Luminance component is carried out color correction process; The chroma blue component is carried out color correction process; The red color component is carried out color correction process.

The invention provides a kind of treatment for correcting of the pseudo color pixel to digital picture.In order to the digital picture that produces pseudo color pixel after the process color correction ARRAY PROCESSING is carried out the correction of pseudo color pixel.Its pixel color according to the relevant position of original image is proofreaied and correct pseudo color pixel.After overcorrect, make this color of pixel can be more near the pixel color of original image.And can not have influence on other color of pixel of digital picture.

Certainly; the present invention also can have other various embodiments; under the situation that does not deviate from spirit of the present invention and essence thereof; those of ordinary skill in the art work as can make various corresponding changes and distortion according to the present invention, but these corresponding changes and distortion all should belong to the protection range of the appended claim of the present invention.

Claims (9)

1. bearing calibration to pseudo color pixel in the digital picture, it is characterized in that in order to proofread and correct the pseudo color pixel through being produced after the color correction ARRAY PROCESSING method that this false colour is handled comprises the following steps:

Obtain an original image, make and utilize a color correction array that this original image is carried out color correction process, handled image in order to generate one;

Handle pixel between image according to a color distortion degree in order to contrast this original image and this, found out the pseudo color pixel in this pixel of having handled image; And

This original image and this this pseudo color pixel of having handled the relevant position of image are carried out color correction process according to following formula:

Pixel _img3＝m*Pixel _imgl+n*Pixel _img2

Wherein, Pixel _Img1Pixel for this original image; Pixel _Img2For this has handled the pixel of image; Pixel _Img3It is an output pixel; M+n=1, m 〉=0, n 〉=0; M value and n value are searched according to a look-up table and are obtained, and the m value is corresponding to this original image, and the n value has been handled image corresponding to this.

2. the bearing calibration to pseudo color pixel in the digital picture according to claim 1, it is characterized in that, this color correction array is the array of a 3*3 pixel size, and selects pel array and this color correction array of corresponding size to carry out color correction process from this original image.

3. the bearing calibration to pseudo color pixel in the digital picture according to claim 1, it is characterized in that, this color correction array is the array of a 4*3 pixel size, and selects pel array and this color correction array of corresponding size to carry out color correction process from this original image.

4. the bearing calibration to pseudo color pixel in the digital picture according to claim 1 is characterized in that, generating this, to have handled image further comprising the steps of:

According to the size of this color correction array, respectively and nonoverlapping pel array that this original image is selected corresponding size carry out this color correction array operation.

5. the bearing calibration to pseudo color pixel in the digital picture according to claim 1 is characterized in that, the color distortion that this original image and this have been handled image determines according to the graphic color colour gamut.

6. the bearing calibration to pseudo color pixel in the digital picture according to claim 5 is characterized in that, carries out in this color correction process, also comprises the following steps:

This pixel of having handled image is generated a corresponding red pixel, a green pixel and a blue pixel;

This red pixel is carried out this color correction process;

This green pixel is carried out this color correction process; And

This blue pixel is carried out this color correction process.

7. the bearing calibration to pseudo color pixel in the digital picture according to claim 1 is characterized in that, the color distortion that this original image and this have been handled image determines according to television system color colour gamut.

8. the bearing calibration to pseudo color pixel in the digital picture according to claim 7 is characterized in that, carries out in this color correction process, also comprises the following steps:

This pixel of having handled image is generated a corresponding luminance component, a chroma blue component and a red color component;

This luminance component is carried out this color correction process;

This chroma blue component is carried out this color correction process; And

This red color component is carried out this color correction process.

9. the bearing calibration to pseudo color pixel in the digital picture according to claim 1, it is characterized in that, this color correction process is according to a look-up table, according to this original image and handled pixel color diversity factor between the image, find out mutually should original image m value and the n value that should handle image mutually.

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