JP3115123B2 - Image signal processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image signal processing apparatus used for, for example, an electronic still camera and the like.
The present invention relates to an image signal processing device that receives R, G, and B color component signals and generates a luminance signal and a color difference signal.

[0002]

2. Description of the Related Art For example, in a digital electronic still camera, a CCD (Charged Coupled Device) is used as an image sensor.
ce) is used. A color filter for separating each color component of RGB (red, green, blue) is mounted on the surface of the CCD for each pixel, and various types of color filters are known. For example, G stripe R / B
Complete checkered color filters are known. This is because the G component signal has a large effect on the resolution, so that the G filter component is alternated between the R filter component and the B filter component in each horizontal scanning direction so that this G component signal is detected by the image sensor in large numbers. , And G filters are arranged so as to be, for example, [GRGB ...], and G filter components are further arranged in a stripe shape in the vertical direction. In this configuration, the R filter component and the B filter component are further arranged in the vertical direction at alternate positions, and the R component and the B component form a checkered pattern.

Conventionally, a G stripe R / B receives R, G, B color component signals from an image sensor having a complete checkerboard color filter to generate a luminance signal Y and color difference signals (RY), (BY). The image signal processing apparatus includes a delay element for delaying a signal corresponding to one horizontal scanning line.
The luminance signal Y and the color difference signals (RY), (BY) for each pixel in each scanning line are obtained from the adjacent color component signals (R, G, B) included in the scanning line. in this case,
And high frequency components Y _H are determined separately for each pixel in order to increase the resolution of the luminance signal Y, and correct the initially computed luminance signal at this final luminance subjected to such further outline correction Was output as a signal.

[0004] Specifically, the luminance signal is expressed as Y = 0.3R + 0.59G +
Determined at 0.11B arithmetic expression, there is one that compensates the high-frequency component Y _H This was prompted by the average value of the vertical two components as a correction value. In this case, for example, G a delayed output at G column, the current outputs "high frequency component of when the luminance signal Y _H = (G + G 'G sought in) / 2 of the arithmetic expression, also, In the R / B column, the high-frequency component Y _H of each luminance signal has been obtained by the arithmetic expression of Y _H = (R + B ′) / 2 or (B + R ′) / 2. The high-frequency component Y _H is the luminance signal Y for each pixel previously obtained.
, And the luminance signal is temporarily reduced to only a low-pass component through a low-pass filter. This luminance signal Y high frequency components Y _H passing through the like are corrected by adding again the high-pass filter is generated. Further, contour correction is performed by coring or the like, and a predetermined luminance signal Y is output.

Further, as a similar apparatus, high frequency components Y _H are 2
In some cases, the average value of the four components in the vertical and horizontal directions in the scanning line is obtained. That is, Y _H = (R + B + 2
G) / 4.

[0006]

However [0005] In the apparatus for obtaining high-frequency components Y _H of the luminance signal from the vertical two components in the two scan lines in a conventional art, respectively by the color boundaries between these pixels When the level difference between the color component signals is large, there is a problem that a false color occurs at the color boundary. That is, when the level difference between the R component and the B component is large in the R / B column, for example, the value obtained by the arithmetic expression of Y _H = (R + B ′) / 2 is equal to the value of the original R component. There is a drawback that the difference is large and the image is displayed as a false color. Further, an apparatus for determining the high frequency component Y _H of the luminance signal from the four components in the horizontal direction and the vertical direction, so that the average value of the four components to the value of 1 pixel, the overall resolution there is a problem that decreases .

The present invention solves such problems of the prior art, and provides an image signal processing apparatus capable of generating an image signal with less occurrence of a false color at a color boundary portion and with less decrease in resolution. The purpose is to:

[0008]

In order to solve the above-mentioned problems, an image signal processing apparatus according to the present invention receives R, G, and B color component signals output from a color image pickup device, and In an image signal processing apparatus for generating a luminance signal Y and color difference signals (RY) and (BY), this apparatus delays color component signals for one scanning line output from an image sensor for each scanning line. A delay means for outputting, a first luminance signal calculating means for calculating a first luminance signal for each pixel from an output from the delay means and an output of a current scanning line from the image sensor, First high-frequency calculating means for calculating a first high-frequency component of a luminance signal for each pixel based on two vertical pixels of a color component signal from the output and the output of the current scanning line; From the output of the current and the output of the current scan line A second high-frequency calculation means for calculating a second high-frequency component of the luminance signal for each pixel based on the four vertical and horizontal pixels of the color component signal, and an output of the delay means or an output of the image sensor A first color difference signal calculating means for calculating a color difference signal (RY) from the output of the first calculating means, and a color difference signal (BY) from the output of the delay means or the output of the image sensor and the output of the first calculating means. ), And the apparatus further includes level difference detection means for detecting a level difference of each pixel between the output of the delay means and the output from the image sensor. The high-frequency calculating means of (2), when the level difference detecting means detects that the level difference of the color component signal exceeds a predetermined value,
An average value of the four color component signals in the horizontal direction and the vertical direction is calculated as a high-frequency component of the luminance signal, and the first high-frequency calculating means determines the level difference of the color component signal by a level difference detecting means. When the following is detected, an average value of two components in the vertical direction is calculated as a high-frequency component of the luminance signal.

This device further subtracts the output of the high-frequency component computed by either the first high-frequency computing means or the second high-frequency computing means from the output of the first luminance signal computing means. Means and a low-pass filter for passing low-frequency components contained in the output from the subtraction means, and the output of the low-pass filter is calculated by the first high-frequency calculation means or the second high-frequency calculation means. And an adding means for adding the output of the high-frequency component. In addition, the apparatus may include a contour correcting unit that further performs a contour correction on an output of the adding unit.

Further, in the image pickup device, filter components transmitting G component signals are arranged in a stripe pattern, and filter components transmitting R component signals and filter components transmitting B component signals are arranged in a checkered pattern therebetween. G stripe R / B including complete checkered color filters. In this case, the level difference detecting means detects the level difference between the R component signal and the B component signal included in the output from the delay means and the current output, and detects the first high frequency calculating means and the second high frequency signal. The range calculation means may be switched based on the level difference between the R component signal and the B component signal detected by the level difference detection means. In this apparatus, the output from the image sensor may be converted into a digital signal and input.

[0011]

According to the image signal processing apparatus of the present invention, the luminance signal for each pixel is obtained from the output of two scanning lines, that is, the current output from the image sensor and the output of the delay means which has delayed the output by one scanning line. And when generating a color difference signal, in particular, once obtaining a first luminance signal from adjacent R, G, B color component signals and obtaining a high-frequency component for correcting the first luminance signal, the level difference detection means The level difference between the respective color component signals from the delay means and the current output is detected, and if the level difference exceeds a predetermined value, the second high frequency calculation means averages the four adjacent color components. The value of the high-frequency component in which the resolution with few false colors is suppressed slightly lower is calculated. If the level difference does not exceed the predetermined value, the first high-frequency calculation means takes the average value of the two components in the vertical direction to obtain the value of the high-frequency component with high resolution. By outputting a luminance signal in which the high-frequency component of the first luminance signal has been corrected by the operation value according to the level difference, an image signal having no false color and a small decrease in resolution is obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an image signal processing apparatus according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 2 shows an embodiment of a digital electronic still camera to which the image signal processing device according to the present invention is applied. In this figure, the object image incident through the lens 10 is a CCD (Ch
(arged coupled device) 12. This CCD1
Reference numeral 2 denotes a fixed imaging device having a two-dimensional photosensitive portion having tens of thousands to hundreds of thousands of pixels. On the surface of the CCD 12, a so-called G stripe R / B perfect checkered color filter is mounted.
In this color filter, a filter component that transmits each color component aligned with, for example, [GRGB ...] is arranged on an odd line, and the positions of the odd line and the R / B component are alternately arranged on an even line, that is, [ GBGR ...] and filter components are arranged, and the G component is formed in a stripe shape in the vertical direction, and the R / B color components are formed in a checkered pattern.

The color component signals transmitted through the color filters and converted into electric signals by the CCD 12 are output as respective color component signals as shown in FIG. These color component signals are sequentially scanned in the horizontal direction and supplied to the imaging system 14. The imaging system 14 is a pre-processing system for performing white balance, gamma correction, and the like of each color component signal obtained from the CCD 12. The color component signal preprocessed by the imaging system 14 is converted into a digital signal by an A / D (analog-digital) converter 16. The A / D converter 16 is an RGB converter in this embodiment.
This is an analog-to-digital converter that converts each analog color signal into a digital signal of 8 to 10 bits. This digital data is supplied to the YC processing block 18.

The YC processing block 18 is a signal processing section to which the image signal processing apparatus of the present invention is applied. The YC processing block 18 converts the data of each color component signal from the A / D converter 16 into a luminance signal.
(Y) and color difference signals (RY) and (BY) are respectively calculated and output by an RGB / YC process processing circuit. The signal processed in the YC processing block 18 is sent to the controller block 20
Via the memory 22. This memory 22 is a frame memory having a capacity of at least one screen,
It is composed of a storage circuit such as AM. The image data from the frame memory 22 is read under the control of the controller block 20, is compressed by the compression processing block 24, and is recorded on a recording medium such as a memory card 26.

The image data stored in the memory 22 is read by the control block 20, and the YC processing block 18 performs a process of displaying the image data on a display or the like via a D / A (digital / analog) converter 28. It is supplied to the reproduction system 30. The reproduction system 30 is, for example,
It consists of a decoder circuit that converts to RGB signals. These units 12 to 30 are respectively controlled by the CPU 32. In particular, the CPU 32 changes the preprocessing value in the imaging system 18,
A central processing circuit that mainly performs control of each unit such as switching between generation processing and reproduction processing in the YC processing block 18, control of data reading and writing in the controller block 20, and setting of a compression value in the compression processing block. .

Next, the functional configuration of the YC processing block 18 in the present embodiment will be described in more detail with reference to FIG. 1. The YC processing block 18 outputs the output from the A / D converter 14 to the line memory 100. , And a connection line 102 directly connected to each section. The output of the connection line 102 and the output of the line memory 100 are supplied to a level difference detection circuit 104, a switching circuit 106, a Y 'operation unit 108, a (B-Y') operation unit 110, and an (R-Y ') operation unit 112. And are respectively connected to.

The line memory 100 is a delay circuit composed of a shift register or the like for accumulating and outputting pixels for each scanning line shown in FIG. 3 for each scanning line. Therefore, each part such as the arithmetic circuits 108 to 112 receiving this is connected to the connection line 10.
2 and the output of the previous scanning line from the line memory 100 are supplied as outputs for two scanning lines, respectively.

The level difference detection circuit 104 is a circuit for comparing the level of the current output from the connection line 102 with the level of the output from the line memory 100, and detecting whether or not these levels exceed a predetermined level difference. is there. Specifically, a comparison circuit that compares the level difference between two color components of two pixels in the vertical direction of the two scanning lines, in this case, the G component and the G component or the R component and the B component, and according to the comparison result, And a circuit for generating a switching signal Sc. The switching signal Sc causes the switching circuit 106 to switch its output to the first Y _H1 operation circuit 114 or the second Y _H2 operation circuit 116.

The switching circuit 106 receives the signal from the line memory 100 and the signal from the connection line 102 in parallel, and
A switching circuit that selects either the Y _H1 operation circuit 114 or the Y _H2 operation circuit 116 and outputs the result in parallel.
The first Y _H1 operation circuit 114 is a circuit that averages the outputs of the two scanning lines from the switching circuit 106 for each pixel to calculate the high-frequency component Y _H of the luminance signal. Specifically, when receiving the first row and the second row scanning line shown in FIG. 3, as the high frequency components Y _H of each of the pixels of the first row _{(G 00 + G 10) /} 2, (R ₀₁ + B
₁₁ ) / 2, (G ₀₂ + G ₁₂ ) / 2 ... are sequentially calculated and output. Similarly, by averaging the upper and lower component by the second and third row scanning lines and outputs the high frequency components Y _H of the second row, the same applies to the third and fourth rows, Contents below seeking the average of the pixel of the line is output as the high frequency components Y _H of the luminance signal for each pixel.

The second Y _H2 operation circuit 116 is a circuit for calculating a value obtained by averaging component signals for four pixels in the vertical and horizontal directions in two scanning lines and outputting the result as a high-frequency component Y _H of the luminance signal. Specifically the first two as a high-frequency component Y _H of each pixel of the first row from the scanning line _{(G 00 + G 10 + R} 01 + B 11) in FIG. 3/4, (R
₀₁ + B ₁₁ + G ₀₂ + G ₁₂ ) / 4, (G ₀₂ + G ₁₂ + B ₀₃ + R ₁₃ ) / 4 ... are sequentially calculated and output. Similarly, the high-frequency component Y _H of each pixel in the second row is calculated by averaging the right component, the lower component, and the diagonally lower right component of the pixel determined in the second and third scanning lines. , and outputs also the third and fourth row taking the average of the components of the four pixels adjacent in the same manner as the high frequency components Y _H of the luminance signal for each pixel.

The high-frequency component Y _H of the first arithmetic circuit 114 or the second arithmetic circuit 116 is subtracted by the subtracter 118 from the output of the Y ′ arithmetic circuit 108. Y 'operation circuit 108
A first luminance signal Y 'is calculated from outputs of two lines from 102 and the line memory 100, respectively. In the present embodiment, the pixel components obtained by the arithmetic expression of Y ′ = 0.3R + 0.59 (G + G ′) / 2 + 0.11B are obtained in the same manner as the second Y _H2 arithmetic circuit 116, and the The right component, the lower component, and the diagonally lower right component are respectively assigned to R, G, G ', and B in the above arithmetic expression, and the first luminance signal Y' is obtained. Specifically, G ₀₀ in FIG.
0.3R ₀₁ +0.59 (G ₀₀ + G ₁₀ ) / 2 +
0.11B ₁₁ is obtained, and so four pixel components R in the two scanning lines, G, G ', the value of each signal value of B is assigned is calculated.

This output is supplied to the (B-Y ') operation circuit 110 and (R
-Y ') is supplied to the arithmetic circuit 112 and to the subtractor 118. Subtractor 118 performs a (Y'-Y _H) subtraction, the output thereof is output as the low-frequency component Y _L of approximately luminance signal. Strictly speaking, the high-pass component Y _H
Is output as the low-frequency component Y _L is completely blocked. The low-pass filter 120 is a filter that passes frequency components of, for example, around 3.5 MHz or less.

On the other hand, the high-frequency component Y _H is supplied to the high-pass filter 122.
Is output to the adder 124 through The high-pass filter 122 is a filter that passes a frequency range of 3.5 MHz or more, contrary to the low-pass filter 120. The output Y _L of the output Y _H and the low-pass filter 120 of the high-pass filter 122 is supplied to the contour correction circuit 124 is a luminance signal to cover the entire band are summed by the adder 124. The contour correction circuit 124 includes a contour emphasizing circuit that attenuates low-frequency components by coring or the like and emphasizes high-frequency components. The output of the contour correction circuit 124 is output from the processing block 12 as a corrected luminance signal Y.

On the other hand, the (B-Y ') operation circuit 110
Alternatively, a color difference signal (B−B) is obtained from the B component signal contained in one of the outputs of the line memory 100 and the luminance signal Y ′ from the Y ′ circuit.
Y ′). This output is output as a color difference signal (BY) through a low-pass filter 128. The (R-Y ') operation circuit 112 is connected to the R component signal contained in either the connection line 102 or the output of the line memory 100.
This is a circuit for forming a color difference signal (R-Y ') from the luminance signal Y' from Y '. This output is output as a color difference signal (RY) through a low-pass filter 130.

In the operating state, the YC processing block 18
Then, the processing of the image data of the four patterns (a) to (e) shown in FIG. 4 is performed. First, in pattern (a),
A luminance signal Y and color difference signals (RY) and (BY) of GR rows and G columns are generated. In this case, the level difference detection circuit 104 outputs a level difference (G) between the output from the line memory 100 and the output from the connection line 102.
_mn- Gm _{(n + 1)} ), and when this value exceeds a predetermined level, the output of the switching circuit 106 is switched to the second _YH2 high-frequency operation circuit 116, and the predetermined level is output. If not, the switching signal Sc is supplied so as to cause the first _YH2 high frequency calculation circuit 114 to switch.

Thus, in the first Y _H operation circuit 114, the high frequency component of the luminance signal is obtained by the operation of Y _H = (G _mn + G _{(m + 1) n} ) / 2, or In the high-frequency operation circuit 116 of
Receiving input of R / B color component signal, Y _H = (G _mn + G _{(m + 1) n} + R _{m (n + 1)}
An average value of four pixels is obtained as a high-frequency component of the luminance signal by an operation of + B _{(m + 1) (n + 1)} ) / 4. These calculation results indicate that the resolution is high when the level difference between the pixels of the two lines is small, that is, when the average of the two pixels is obtained, and when the level difference is large, the resolution is slightly lowered by averaging the four pixels. This is a value that prevents the generation of false colors.

The output of one of these high-frequency operation circuits 114 and 116 is subtracted from the output Y 'from the Y' operation circuit 106.
The Y 'operation circuit 106 reads the four color component signals and
= Seeking luminance signal Y 'by the operation of _{0.3R m (n + 1) +0.59} (G mn + G (m + 1) n) /2+0.11B (m + 1) (n + 1). The luminance signal Y ′ is calculated by the (R−Y ′) calculation circuit 112 as Rm _{(n + 1)} −Y ′. Similarly, in the (B-Y ') arithmetic circuit 110, (B _{(m + 1) (n + 1)}
−Y ′) is performed. These are output through low-pass filters 128 and 130, respectively, and output as color difference signals (RY) and (BY) at the mn pixel.

On the other hand, the luminance signal Y ', at subtracting circuit 118 are high frequency components Y _H subtraction, passed through the low-pass filter 120 is output to the adder circuit 124 as a low-frequency component Y _L. This corrected high-frequency component Y _H passing through the high pass filter 122 is again at summed with full-band luminance signal Y is generated. This is further subjected to contour correction by a contour correction circuit 126 and output. Thus, the corrected luminance signal Y in the mn-th row
And a color difference signal are calculated as outputs of the G pixels.

In the case of the second pattern (b), Y '= 0.3R _mn +0.59 (G _{m (n + 1)} + G
_{(m + 1) (n + 1)} ) / _{2 +} 0.11B The operation of _{(m + 1) n} is performed, and according to the level difference between the color component R _mn and the color component B _{m (n + 1).} hand,
Y _H1 = (B _mn + R _{(m + 1) n} ) / 2 or Y _H2 = (G _mn + G _{(m + 1) n} + R
The calculation of _{m (n + 1)} + B _{(m + 1) (n + 1)} ) / 4 is performed by the high-frequency operation circuits 114 and 116.
Both subtraction and low-pass filtered if at conducted with Y _H from Y 'as above, which is corrected Y = Y _L + Y _H further addition of high-pass filtered Y _H and contour correction The output luminance signal Y is output.

In this case, the (R-Y ') arithmetic circuit 112 and the (B-Y') arithmetic circuit 114 _generate (R _mn -Y ') and (B _{m (n + 1)} -Y')
Are calculated and output as color difference signals of R pixels in the mn-th row. Also in this case, when the level difference between the high frequency component Y _{H and the} R / B component is large, the resolution is slightly reduced to reduce the false color by averaging the four pixels, and when the level difference is small, Can take the average of two vertical pixels and enhance that pixel with a higher resolution than four pixels.

Similarly, in the case of the third pattern (C),
Generation of Y 'from the four components, and performs generation of high-frequency component Y _H from the average value of the color component of the two pixels or four pixels corresponding to the level difference between the two lines, the first luminance as above signal
A luminance signal Y corrected by subtraction, addition, and contour correction from Y ′ is generated, and a color difference signal is formed by each of the arithmetic circuits 110 and 112 to form YC pixel data of G pixels similar to the first pattern. You. Even if the fourth pattern of (d) third pattern and is selected from the color components of the high frequency component Y _H of 4 pixels or 2 pixels according to the level difference between the R / B as well, thereby similarly to the above A corrected luminance signal Y is generated,
Further, color difference signals are generated in the same manner as described above.

By repeating these four patterns (a) to (d) in the YC processing block 12, all the pixels
Each of the YC image data is generated and stored in the frame memory 22.
Are sequentially stored. Therefore, the image displayed or printed by the image data in the present embodiment can be reproduced with little occurrence of false colors at the color boundary portion and high resolution in other portions.

In the above embodiment, the level difference detecting circuit 104 is configured to compare the level difference between the pixel for generating the YC data and the pixel on the next line.
Since the operation of the high-frequency component Y _H of the column is less occurrence of false color can be performed only switched on R / B pixel. That is, the level difference detection circuit 104 may be a circuit that detects only the level difference between the R / B components arranged in the vertical direction.

[0034]

As described above in detail, according to the image signal processing apparatus of the present invention, when the high frequency component of the luminance signal is obtained, if the level difference between the components of each pixel over two lines is large, The calculation is performed as an average value for four pixels in the horizontal and vertical directions, and when the level difference is small, switching is performed as an average value for the two pixels in the vertical direction. It is possible to generate image data with a higher resolution in portions other than. Therefore, the image reproduced from the image data is displayed as an image which is easy to see and has no uncomfortable feeling.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an embodiment of an image signal processing device according to the present invention.

FIG. 2 is a block diagram illustrating a functional configuration of an electronic still camera to which the image signal processing device according to the embodiment is applied.

FIG. 3 is a diagram showing a pixel data arrangement in the embodiment.

FIG. 4 is a diagram showing pixel data arrangement of four patterns in the embodiment.

[Explanation of symbols]

100 Line memory 102 Connection line 104 Level difference detection circuit 106 Switching circuit 108 Y 'operation circuit 110 (B-Y') operation circuit 112 (R-Y ') operation circuit 114 Y _H1 operation circuit 116 Y _H2 operation circuit 118 Subtraction circuit 120,128,130 Low pass filter 122 High pass filter 124 Adder circuit 126 Contour correction circuit

Claims (6)

(57) [Claims] 1. The R, G, and R output from a single- chip color image sensor.
B In an image signal processing device that receives each color component signal and generates a luminance signal Y and color difference signals (RY) and (BY) for each pixel, the device includes one scanning line output from the image sensor. Delay means for delaying and outputting the color component signals for every one scanning line, and a first luminance for each pixel from the output from the delay means and the output of the current scanning line from the image sensor. A first luminance signal calculating means for calculating a signal, a first luminance signal calculating means for each pixel based on two vertical pixels of the color component signal from the output of the delay means and the output of the current scanning line. First high-frequency calculating means for calculating a high-frequency component; and a luminance signal for each pixel based on the vertical and horizontal four pixels of the color component signal from the output of the delay means and the output of the current scanning line. Plays the second high-frequency component of A second color difference signal calculating means for calculating a color difference signal (RY) from the output of the delay means or the output of the image sensor and the output of the first luminance signal calculating means. And second color difference signal calculating means for calculating a color difference signal (BY) from the output of the delay means or the output of the image sensor and the output of the first luminance signal calculating means. A level difference detection unit for detecting a level difference between an output of the delay unit and an output from the image sensor for each pixel, wherein the second high-frequency calculation unit uses a color component in the level difference detection unit. When it is detected that the signal level difference exceeds a predetermined value, an average value of the four color component signals in the horizontal direction and the vertical direction is calculated as a high frequency component of the luminance signal, and the first high level is calculated. The gamut calculating means is a means for calculating the color component signal by the level difference detecting means. When the level difference that has been detected is less than a predetermined value, the image signal processing apparatus characterized by calculating the high-frequency component of the luminance signal the average value of the vertical two components. 2. The image signal processing apparatus according to claim 1, wherein the apparatus is configured to output the first high frequency computing means or the second high frequency computing means from an output of the first luminance signal computing means. Subtracting means for subtracting the output of the high-frequency component calculated in any one of them; a low-pass filter for passing a low-frequency component included in the output from the subtracting means; an output of the low-pass filter; An image signal processing device comprising: an adding unit that adds an output of a high-frequency component calculated by the first high-frequency calculating unit or the second high-frequency calculating unit. 3. The image signal processing apparatus according to claim 2, wherein said apparatus further includes a contour correcting means for performing a contour correction on an output of said adding means. 4. The image signal processing apparatus according to claim 1, wherein the image sensor has a filter component that transmits a G component signal arranged in a stripe pattern, and a filter component and a B component that transmit an R component signal therebetween. G stripe R / B in which filter components transmitting component signals are arranged in a checkered pattern
An image signal processing device equipped with a complete checkered color filter. 5. The image signal processing device according to claim 4, wherein said level difference detecting means detects a level difference between an R component signal and a B component signal included in an output from said delay means and a current output. Detecting, the first high-frequency operation means and the second high-frequency operation means,
An image signal processing apparatus wherein switching is performed based on a level difference between an R component signal and a B component signal detected by the level difference detecting means. 6. The image signal processing apparatus according to claim 1, wherein an output from the image sensor is converted into a digital signal and input.