JP2002185977A - Video signal processor and recording medium with video signal processing program recorded thereon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain good white balance even when a chromatic subject occupies the large area of a photographic picture. SOLUTION: The photodetective surface of a color imaging device is divided into plural areas and the pixel output average of each color in each area is calculated. The rate of the pixel output average of another color to that of a color to be a standard is calculated by each area. Then, the hue of each area is detected based on the rate of the pixel output average and an area of a hue equal to or lower than a prescribed frequency is extracted from among plural areas based on the frequency distribution of the house in the plural areas to adjust the white balance based on the pixel output of each color in the extracted area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for processing a video signal input from a color image sensor and a recording medium on which a processing program is recorded, and more particularly, to an apparatus having improved white balance performance.

[0002]

2. Description of the Related Art A video signal processing apparatus such as an electronic still camera or a video camera for processing a video signal captured by a color image sensor and performing white balance adjustment for correctly reproducing a white portion of a subject in white is known. (For example, see Japanese Patent No. 29997234).

FIG. 9 is a control block diagram of a conventional video signal processing circuit, and the conventional white balance adjustment will be briefly described with reference to FIG. This camera includes a TTL type imaging device and a video signal processing device. The subject image formed on the color image sensor 52 by the photographing lens 51 is converted by the color image sensor 52 into a video electric signal. The luminance signal processing section 53 generates a luminance signal Y from the video signal, and the chroma signal processing section 54 generates a low frequency component YL, a red signal R, and a blue signal B of the luminance signal from the video signal. Here, the luminance signal Y is

## EQU1 ## A signal obtained by mixing red R, green G, and blue B at a ratio of Y = 0.30R + 0.59G + 0.11B.

[0004] The red signal R is multiplied by a white balance gain Rgain of the red signal in an R gain control unit 55 to generate a red signal R '. On the other hand, the blue signal B is multiplied by the white balance gain Bgain of the blue signal in the B gain control unit 56 to generate a blue signal B ′. Next, the matrix amplifier 57 generates a color difference signal RY based on the red signal R 'and the low frequency component YL of the luminance signal, and the matrix amplifier 58 generates the color difference signal RY based on the blue signal B' and the low frequency component YL of the luminance signal. A color difference signal BY is generated. here,

## EQU00002 ## RY = 0.70R-0.59G-0.11B, BY = 0.89B-0.59G-0.30R These color difference signals RY and BY are compression-processed. It is sent to 59 and compressed to JPEG or the like and recorded on a recording medium.

On the other hand, the averaging units 60 and 61 calculate the average values of the color difference signals RY and BY for one screen, respectively, and the control voltage deriving unit 62 sets the average signal level to 0 level, that is, R = The white balance gains Rgain and Bgain that satisfies B = G are derived. As described above, these white balance gains Rgain and Bgain are multiplied by the red signal R and the blue signal B, respectively, to perform white balance adjustment.

[0006]

However, in the conventional video signal processing apparatus, when shooting a scene in which a chromatic subject occupies a wide area of a shooting screen, the subject is strongly affected by the color of the subject, and a white image is correctly obtained. There is a problem that balance adjustment is not performed.

An object of the present invention is to obtain a good white balance even when a chromatic object occupies a wide area of a photographing screen.

[0008]

The present invention will be described with reference to FIGS. 5 and 6 showing an image processing program according to an embodiment. (1) The invention of claim 1 forms an image by a photographing lens. The present invention is applied to a video signal processing apparatus that includes a color image sensor that converts a subject image into an electric signal, and performs white balance adjustment by processing pixel outputs of each color input from the color image sensor. An area dividing means (S5) for dividing the light receiving surface of the color image sensor into a plurality of areas; an average value calculating means (S6) for calculating an average pixel output value for each color of each area; Average value ratio calculating means (S7) for calculating a ratio of a pixel output average value of another color to a pixel output average value of a reference color, and detecting a hue of each area based on the ratio of the pixel output average values. Hue detecting means (S8,
S9), and a region extracting means (S10) for extracting a region having a hue of a predetermined frequency or less from the plurality of regions based on a frequency distribution of hues of the plurality of regions, wherein each color of the extracted region is provided. (S11, S12, S14). (2) The video signal processing device according to claim 2, wherein a sum calculation means (S11) for calculating a sum of pixel output average values for each color of the extracted area, and a non-reference color based on the sum of each color. A gain calculating means (S12) for calculating a white balance gain for a color, and a pixel output adjusting means (S14) for multiplying a pixel output of a color other than the reference color by the white balance gain, perform white balance adjustment. (3) According to a third aspect of the present invention, a video signal is input from a color imaging device that converts a subject image formed by a photographing lens into an electric signal, and a process is performed on pixel outputs of each color included in the video signal. The method is applied to a computer-readable recording medium on which a video signal processing program for performing white balance adjustment is recorded. The area division processing (S5) for dividing the light receiving surface of the color image sensor into a plurality of areas. Average value calculation processing (S6) for calculating the pixel output average value, and average value ratio calculation processing (S7) for calculating the ratio of the pixel output average value of the other color to the reference color pixel output average value for each region. ) And a hue detection process for detecting the hue of each area based on the ratio of the pixel output average value (S8, S8)
9) and an area extraction process (S10) for extracting an area having a hue of a predetermined frequency or less from the plurality of areas based on the frequency distribution of hues of the plurality of areas, and performing each color of the extracted area. (S11, S12, S14). (4) A computer-readable recording medium on which the video signal processing program according to claim 4 is recorded, wherein a sum total calculation process (S11) for calculating a sum of pixel output average values for each color of the extracted area; A gain calculation process (S12) for calculating a white balance gain for a color other than the reference color based on the sum of the above, and a pixel output adjustment process (S14) for multiplying a pixel output of a color other than the reference color by the white balance gain. , Adjust the white balance. (5) In a computer-readable recording medium on which the video signal processing device or the video signal processing program according to claim 5 is recorded, the color imaging element has pixels of a red component, a green component, and a blue component, and the reference color is It is green. (6) The color image sensor of the computer-readable recording medium on which the video signal processing device or the video signal processing program according to claim 6 is recorded has pixels of a green component, a yellow component, a blue-green component, and a violet component, The reference color is green. (7) A computer-readable recording medium storing the video signal processing device or the video signal processing program according to claim 7 is an image sensor for recording a subject image captured by the image sensor. (8) A computer-readable recording medium storing the video signal processing device or the video signal processing program according to claim 8, wherein the image pickup device divides an object field into a plurality of photometric areas and outputs a subject brightness for each of the photometric areas. Is an image pickup device for measuring. (9) A ninth aspect of the present invention includes a color image sensor for converting a subject image formed by a photographic lens into an electric signal, and performs white balance adjustment by performing processing on pixel output of each color input from the color image sensor. The present invention is applied to a video signal processing device that performs the processing. An area dividing unit that divides a light receiving surface of the color image sensor into a plurality of areas; a hue calculating unit that calculates a hue of each area based on a pixel output of each area;
A hue distribution calculating means for calculating a frequency distribution of hues in a plurality of areas; and an area extracting means for extracting an area having a predetermined frequency or less from the hue frequency distribution. Perform balance adjustment. (10) According to a tenth aspect of the present invention, a video signal is input from a color image sensor that converts a subject image formed by a photographic lens into an electric signal, and a pixel output of each color included in the video signal is processed. The present invention is applied to a computer-readable recording medium on which a video signal processing program for performing white balance adjustment is recorded. Then, an area dividing process of dividing the light receiving surface of the color image sensor into a plurality of regions, a hue calculating process of calculating a hue of each region based on a pixel output of each region, and a frequency distribution of hues of the plurality of regions are performed. The hue distribution calculation processing to be calculated and the area extraction processing to extract an area having a frequency equal to or less than a predetermined frequency from the hue frequency distribution are performed, and the white balance is adjusted based on the pixel output of each color of the extracted area.

In the section of the means for solving the above-described problem, a diagram of one embodiment is used for easy understanding of the description, but the present invention is not limited to the embodiment. .

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a TTL single-lens reflex electronic still camera will be described. Note that the present invention is not limited to a TTL single-lens reflex electronic still camera,
The present invention can be applied to all electronic still cameras, video cameras, scanners, and the like, such as a perspective finder type, which captures an image with a color imaging element such as a CCD.

FIG. 1 shows a cross section of a camera according to an embodiment, and FIG. 2 shows a configuration of the camera. In this TTL single-lens reflex camera, an interchangeable lens barrel 2 is mounted on a camera body 1. Light from the subject enters the lens barrel 2, passes through the aperture of the photographing lens 3 and the aperture 4 in the lens barrel 2, and is guided to the camera body 1.

In the camera body 1, the main mirror 5 is placed at a position shown by a dashed line except during photographing, and the subject light is reflected by the main mirror 5 and guided to the finder mat 6,
A subject image is formed on the viewfinder mat 6. The subject image is guided to the eyepiece 8 by the pentaprism 7 and is visually recognized by the photographer via the eyepiece 8.

The subject image formed on the finder mat 6 is guided to an imaging lens 10 by a pentaprism 7 and a prism 9, and the subject image is re-formed on the photometric image sensor 11 by the imaging lens 10. Imaged. The photometric imaging device 11 is composed of a photodiode or a CCD,
The object scene is divided into a plurality of photometric areas, and the subject brightness is measured for each photometric area.

On the other hand, at the time of photographing, the main mirror 5 is retracted to the position shown by the solid line.
The light passes through the shutter 13 that is opened through the light-emitting device, and is guided to the image pickup device 14 for imaging, and a subject image is formed on the image pickup device 14. A part of the subject light is reflected by the sub-mirror 12 and guided to a focus detection device (not shown) installed at the bottom of the camera body 1 to detect a focus adjustment state of the photographing lens 3.

The image pickup device (CCD) 14 for photography has a plurality of pixels arranged on a plane, and a red R, green G, and blue B color filter is arranged on each pixel as shown in FIG. I have. It is also possible to use an image sensor in which complementary color filters of green G, yellow (yellow) Ye, blue-green (cyan) Cy, and purple (magenta) Ma as shown in FIG. 4 are arranged. Note that an image pickup device provided with such a color filter is referred to as a color image pickup device in this specification.

In FIG. 2, a CPU 21 controls the operation of the entire camera. The CPU 21 controls the timing generator (TG) 22 and the driver 23 to drive the above-described color imaging device (CCD) 14 for photographing. The CPU 21 controls the timing generator 22 to control the analog signal processing circuit 24, the A / D converter 25, the image processing circuit (ASIC) 26, and the buffer memory 27.

The analog signal processing circuit 24 performs analog processing such as gain control and noise removal on the analog R, G, and B signals input from the color image sensor 14. The A / D converter 25 converts analog R, G, B signals into digital signals. Also, an image processing circuit (ASIC)
26 performs processing such as white balance adjustment, γ correction, and interpolation contour compensation on the digital R, G, and B signals. The operation of the image processing circuit 26 will be described later.

The buffer memory 27 stores image data during or after image processing. Compression circuit (JPE
G) 28 compresses the image data stored in the buffer memory 27 at a predetermined ratio by the JPEG method. The display image generation circuit 29 generates display image data from the image data stored in the buffer memory 27 and displays the display image data on the monitor 30. The memory card 31 is composed of a flash memory or the like, and records compressed image data. Further, a half-press switch 32 and a full-press (release) switch 33 of a shutter release button are connected to the CPU 21.

Each time the shutter 13 is released and photographing is performed, the CPU 21 accumulates charges in the color image pickup element 14, reads out the accumulated charges, and performs signal processing by the analog signal processing circuit 24 and the A / D converter 25. After the digital conversion, the image processing circuit 26 performs processing. And
The captured image is displayed on the monitor 30, and the image is compressed by the compression circuit 28 and recorded on the memory card 31.

An image processing circuit (ASIC) 26 comprises a CPU and its peripheral parts, and executes an image processing program shown in FIGS. 5 and 6 to process R, G, B image signals. In this embodiment, an example in which image processing is performed by software of a microcomputer is described, but image processing may be performed by hardware.

In step 1, the color image sensor 14
The R, G, and B pixel data output from the A / D converter 25 and converted into digital signals by the A / D converter 25 are input. In the following step 2, for each line of the pixel array, a weighted average of a plurality of pixel data used as optical black is subtracted from each pixel data of the line. In step 3,
For each line of the pixel array, a predetermined gain is uniformly applied to each of the R, G, and B pixel data to adjust the signal level, and to correct the variation in the sensitivity of the R and B pixels with respect to the G pixel. .

In step 4, the RGB pixel data subjected to the above processing is output to the buffer memory 27 and stored therein.
White balance gain Rga based on GB pixel data
Calculate in and Bgain.

A method of calculating the white balance gains Rgain and Bgain will be described. First, in step 5, the light receiving surface of the image sensor 14 in which a plurality of pixels are arranged on a plane is divided into a plurality of regions including at least two or more pixels. In this region division method, in principle, the same number of pixels are included,
A method of dividing each area so that they do not overlap each other, a method of including the same number of pixels as a rule, and a method of dividing each area so that they overlap each other. There is a method of dividing the area into smaller areas, that is, a method of changing the size of the area based on the calculation result, or a method of combining the above methods. The method of dividing the area is not limited to the method of this embodiment.

The division method allowing the overlap of the area can calculate a more accurate white balance gain as compared with the division method not allowing the overlap. However, if the amount of overlap is increased, it will be described later. A problem occurs when the range of the chromatic subject is excluded from the shooting screen. In the division method of, the operation is performed in a wide area division at first, and when a highly reliable operation result cannot be obtained, the calculation is performed again in a narrow area division, thereby shortening the operation processing time.

Each area divided into n parts by any of the methods is distinguished by giving an area number i (= 1 to n). In step 6, average values Ra (i), Ga (i), and Ba (i) of pixel values for each of R, G, and B included in each area i are calculated. In the following step 7, the ratio RG (i) of the average R pixel value Ra (i) to the average G pixel value Ga (i) in each region i, and the average B pixel value Ba (i) to the average G pixel value Ga (i) ) Is calculated by the following equation.

RG (i) = {Ra (i) −Ga (i)} / Ga (i), BG (i) = {Ba (i) −Ga (i)} / Ga (i)

Next, in step 8, as shown in FIG.
The ratio RG (i) of each region i of the calculation result is plotted on a plane coordinate where the horizontal axis represents the ratio BG of the B pixel average value to the G pixel average value and the vertical axis represents the ratio RG of the R pixel average value to the G pixel average value. And ratio B
The points {RG (i), BG (i)} determined by G (i) are plotted. In Step 9, the origin (0,0) is obtained in the plane coordinates shown in FIG.
The frequency distribution of the points {RG (i), BG (i)} for each radiation range from is examined, and a histogram as shown in FIG. 8 is created. In this embodiment, a radiation range of 10 degrees will be described as an example, but the angle of the radiation range is not limited to this embodiment.

The ratio R of the average R pixel value to the average G pixel value R
On the plane coordinates of G and the ratio BG of the average value of the B pixel to the average value of the G pixel, the position where the point {RG (i), BG (i)} of the region i exists is the presence of the subject corresponding to the region i. Since the coloring is represented, that is, the hue is represented, the frequency distribution of the points {RG (i), BG (i)} for each radiation range shown in FIG. 7 indicates the hue tendency of the subject. For example, when the blue sky occupies a wide range of the photographing screen, the ratio BG increases, and the frequency of the radiation range around the horizontal axis BG increases. Further, when photographing a whole red rose garden, the ratio RG increases, and the frequency of the radiation range around the vertical axis RG increases.

However, as described above, when photographing a scene in which such a chromatic subject occupies a wide area of the photographing screen, a good white balance cannot be obtained due to the strong influence of the color of the subject. . Therefore, in this embodiment, it is determined that a chromatic subject occupying a wide range of the photographing screen exists in a region i having a hue exceeding a predetermined frequency K, and such a region is excluded from a target region of white balance gain calculation. . As a result, white balance adjustment can be performed while excluding a chromatic subject that occupies a wide range in the shooting screen, and a good adjustment result can be obtained.

More specifically, in step 10, an area i having a frequency equal to or less than a predetermined value K is extracted from the histogram shown in FIG.
The sum of the average values of the G and B pixels is calculated by the following equation.

Rt = ４Ra (i), Gt = ΣGa (i), Bt = ΣBa (i) Then, in step 12, white balance gains Rgain and Bgain are calculated based on the sums Rt, Gt and Bt by the following equation. .

## EQU5 ## Rgain = Rt / Gt, Bgain = Bt / Gt

After calculating the white balance gains Rgain and Bgain, the RGB pixel data previously stored is input from the buffer memory 27 in step 13, and all the R pixel values are multiplied by the gain Rgain. Multiply Bgain to adjust white balance.

Step 14 after white balance adjustment
Then, well-known black level adjustment and gamma correction are performed. Further, in step 15, known interpolation and contour processing are performed for each of the vertical p × horizontal q pixel regions. That is, the image data after the white balance adjustment is subjected to a format process for JPEG data compression for each block data in the p × q pixel area, and the Y signal in the p1 × q1 pixel area and p2 × q2
A Cb signal and a Cr signal for the pixel area are generated. The above-described black level adjustment, γ correction, and interpolation contour processing are well known, and are not directly related to the present invention. Finally, in step 15, the Y signal, the Cb signal, and the Cr signal are output to the buffer memory 27 and stored.

As described above, the light receiving surface of the color image sensor 14 is divided into a plurality of regions i, and the average pixel output values Ra (i), Ga (i), and Ba for the colors R, G, and B of each region i. (i) is calculated, and the pixel output average value Ra of the other colors R and B with respect to the pixel output average value Ga (i) of the reference color G for each region i.
(i) The ratios RG (i) and BG (i) of Ba (i) are calculated. Then, the hue of each area i is detected based on the pixel output average value ratios RG (i) and BG (i), and the predetermined frequency is determined from the plurality of areas i based on the frequency distribution of the hue of the plurality of areas i. Since a region having a hue equal to or less than K is extracted and white balance adjustment is performed based on the pixel output of each color in the extracted region, a good white balance can be obtained even when a chromatic subject occupies a wide area of the shooting screen. Obtainable.

In the configuration of the above embodiment, the image processing circuit (ASIC) 26 includes area dividing means, average value calculating means, average value calculating means, hue detecting means, area extracting means,
The summation means, the gain calculation means, the pixel output adjustment means, the hue calculation means and the hue distribution calculation means are constituted.

In the above-described embodiment, the plane coordinate system of the ratio RG of the average R pixel value to the average G pixel value and the ratio BG of the average B pixel value to the average G pixel value is set.
The example in which the hue tendency of the subject in each area is determined has been described. However, the present invention is not limited to the coordinate system described above. For example, XYZ, LAB, L
Any coordinate system that represents a hue such as UV or HSC may be used.

In the above-described embodiment, an example in which white balance adjustment is performed using the output of the color imaging device 14 for photographing has been described. After making adjustments,
Similar effects can be obtained.

Further, in the above-described embodiment, an image pickup device having three primary color filters of R, G, and B using green as a reference color has been described as an example. The arrangement and the reference colors are not limited to those in the above-described embodiment. For example, similar effects can be obtained by using an image sensor having a complementary color filter of G, Ye, Cr, and Ma.

[0037]

As described above, according to the present invention, the light receiving surface of the color image sensor is divided into a plurality of regions, the average pixel output value for each color in each region is calculated, and the reference value is calculated for each region. The ratio of the pixel output average value of the other color to the pixel output average value of the color to be calculated is calculated. Then, the hue of each area is detected based on the ratio of the pixel output average values, and a hue area having a predetermined frequency or less is extracted from the plurality of areas based on the hue frequency distribution of the plurality of areas, and the extracted area is extracted. The white balance adjustment is performed based on the pixel output of each color, so that a good white balance can be obtained even when a chromatic subject occupies a wide area of the shooting screen. Further, according to the present invention, the above effects can be obtained not only with color image sensors of the three primary colors of R, G and B, but also with color image sensors of the complementary colors of G, Ye, Cy and Ma. Further, according to the present invention, the above-described effects can be obtained not only with the imaging element for photographing but also with the imaging element for photometry.
Further, according to the present invention, the light receiving surface of the color image sensor is divided into a plurality of regions, and the hue of each region is calculated based on the pixel output of each region, and the frequency distribution of the hue of the plurality of regions is calculated. Then, an area having a frequency equal to or less than a predetermined frequency is extracted from the frequency distribution of the hue, and the white balance is adjusted based on the pixel output of each color in the extracted area. However, a good white balance can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a camera according to an embodiment.

FIG. 2 is a diagram illustrating a configuration of an embodiment.

FIG. 3 is a diagram illustrating an example of the arrangement of R, G, and B pixels of a color image sensor.

FIG. 4 is a diagram showing a complementary color pixel array of the color image sensor.

FIG. 5 is a flowchart illustrating image processing according to an embodiment.

FIG. 6 is a flowchart showing image processing according to the embodiment, following FIG. 5;

FIG. 7 is a diagram in which ratios RG and BG of pixel average values are developed on a plane.

FIG. 8 is a diagram showing a histogram with respect to a radiation range.

FIG. 9 is a diagram illustrating a configuration of a conventional image processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Photometric color imaging element 14 Color imaging element for photography 21 CPU 22 Timing generator 23 Driver 24 Analog signal processing circuit 25 A / D converter 26 Image processing circuit (ASIC) 27 Buffer memory 28 Compression circuit (JPEG) 29 Display image generation Circuit 30 Monitor 31 Memory card

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 9/79 H04N 9/79 GF Term (Reference) 2H002 DB02 DB14 DB17 DB25 EB01 EB09 GA32 GA33 HA01 JA07 JA08 ZA03 2H054 AA01 5C055 BA05 BA06 EA02 EA03 EA04 HA16 HA36 HA37 5C065 AA01 AA03 BB02 CC02 CC03 DD02 DD17 EE01 EE02 FF03 GG15 GG17 GG22 GG24 5C066 AA01 BA02 CA08 CA17 EA04 EA15 EC02 GA05 KA02 JA02

Claims (10)

[Claims] 1. A video signal processing device comprising: a color image sensor for converting a subject image formed by a photographing lens into an electric signal; and performing white balance adjustment by processing pixel outputs of respective colors input from the color image sensor. In the apparatus, an area dividing unit that divides a light receiving surface of the color image sensor into a plurality of areas, an average value calculating unit that calculates an average pixel output value for each color of each area, and a reference color for each area. An average value ratio calculating unit that calculates a ratio of a pixel output average value of another color to a pixel output average value; a hue detecting unit that detects a hue of each area based on the ratio of the pixel output average values; Region extracting means for extracting a region having a hue of a predetermined frequency or less from the plurality of regions based on a frequency distribution of hues of the region, and a white portion based on a pixel output of each color of the extracted region. Video signal processing device and performs balance adjustment. 2. The video signal processing device according to claim 1, wherein: a sum calculating means for calculating a sum of pixel output average values for each color of the extracted region; and a reference color other than the reference color based on the sum of the colors. Video signal processing, comprising: a gain calculating means for calculating a white balance gain for the color of the color; and a pixel output adjusting means for multiplying a pixel output of a color other than the reference color by the white balance gain. apparatus. 3. A white balance adjustment is performed by inputting a video signal from a color image pickup device that converts a subject image formed by a photographing lens into an electric signal, and performing processing on pixel outputs of respective colors included in the video signal. In a computer-readable recording medium on which a video signal processing program is recorded, an area dividing process for dividing a light receiving surface of the color image sensor into a plurality of areas, and an average value calculation for calculating an average pixel output value for each color in each area. Processing, an average value ratio calculation process of calculating a ratio of a pixel output average value of another color to a pixel output average value of a reference color for each region, and an average value ratio calculation process of each region based on the ratio of the pixel output average values. Hue detection processing for detecting hue, and area extraction processing for extracting a hue area having a predetermined frequency or less from the plurality of areas based on the frequency distribution of hues of the plurality of areas, Performed, a computer readable recording medium recording the video signal processing program, characterized in that the white balance adjustment is performed based on the pixel output of each color of the extracted region. 4. A computer-readable recording medium on which the video signal processing program according to claim 3 is recorded, wherein: a sum calculation processing for calculating a sum of pixel output average values for each color of the extracted area; A gain calculation process of calculating a white balance gain for a color other than the reference color based on the sum of each color, and a pixel output adjustment process of multiplying a pixel output of a color other than the reference color by the white balance gain are performed. A computer-readable recording medium having recorded thereon a video signal processing program. 5. A computer-readable recording medium on which the video signal processing device or the video signal processing program according to claim 1 is recorded, wherein the color image pickup device includes a red component, a green component, and a blue component. A video signal processing device or a computer readable recording medium storing a video signal processing program, the pixel having component pixels, and the reference color is green. 6. A computer-readable recording medium on which the video signal processing device or the video signal processing program according to claim 1 is recorded, wherein the color image pickup device comprises a green component, a yellow component, and a blue component. A computer readable recording medium having a video signal processing device or a video signal processing program, wherein the video signal processing device has a green component and a purple component pixel and the reference color is green. 7. A computer-readable recording medium on which the video signal processing device or the video signal processing program according to claim 1 is recorded, wherein the imaging element records a captured subject image. A video signal processing device or a computer readable recording medium storing a video signal processing program. 8. A computer-readable recording medium on which the video signal processing device or the video signal processing program according to claim 1 is recorded, wherein said imaging element divides an object field into a plurality of photometric areas. A video signal processing device or a computer readable recording medium storing a video signal processing program, wherein the video signal processing device is an image sensor for measuring subject brightness for each photometry area. 9. A video signal processing device comprising: a color image sensor for converting a subject image formed by a photographing lens into an electric signal; and performing white balance adjustment by processing pixel outputs of respective colors input from the color image sensor. In the apparatus, an area dividing unit that divides a light receiving surface of the color imaging device into a plurality of areas, a hue calculating unit that calculates a hue of each area based on a pixel output of each area, and a hue calculation unit that calculates a hue of the plurality of areas. A hue distribution calculating means for calculating a frequency distribution; and an area extracting means for extracting an area having a frequency equal to or less than a predetermined frequency from the frequency distribution of the hue, and performing white balance adjustment based on a pixel output of each color of the extracted area. A video signal processing device characterized by the above-mentioned. 10. A white balance adjustment is performed by inputting a video signal from a color image sensor for converting a subject image formed by a photographing lens into an electric signal, and performing processing on pixel outputs of respective colors included in the video signal. In a computer-readable recording medium on which a video signal processing program is recorded, an area dividing process of dividing the light receiving surface of the color image sensor into a plurality of areas, and calculating a hue of each area based on a pixel output of each area. A hue calculation process, a hue distribution calculation process for calculating a frequency distribution of hues of the plurality of regions, and a region extraction process for extracting a region having a predetermined frequency or less from the hue frequency distribution. Computer-readable recording of a video signal processing program characterized by performing white balance adjustment based on pixel output of each color Capacity recording medium.