JPH06141337A - Digital signal processing camera - Google Patents

Abstract

PURPOSE:To provide a digital signal processing camera in which a hue and a brightness of a part are changed by detecting the part in a specific color of a picked-up picture. CONSTITUTION:A color detection section 7 detects a specific color as to digital image pickup signals R, G, B obtained by an image pickup processing section 1, various correction coefficients of a digital arithmetic operation section 8 are varied by a coefficient control section 9 to apply processing such as color correction processing by a color correction circuit 11 and gamma correction, pedestal processing, gamma correction, knee correction processing and contour correction processing or the like by process processing circuits 12R, 12G, 12B to the image pickup signal of the specific color.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital signal processing camera which digitizes an image pickup signal, digitally processes it and outputs it.

[0002]

2. Description of the Related Art Generally, a video signal handled by a video camera or a video tape recorder is subjected to various signal processing such as gamma correction, contour correction, white balance adjustment and hue adjustment.

For example, in the case of a color video camera, a CCD
An image pickup signal processing circuit that forms and outputs a luminance signal and a chroma signal from an image pickup output signal obtained by an image pickup unit using an image sensor, etc., in the signal processing such as gamma correction, contour correction, white balance adjustment, and hue adjustment. Is to be applied.

In a digital signal processing camera that digitizes an image pickup signal and outputs it after digital processing, the gamma correction and the contour correction are performed based on control parameters written in a nonvolatile memory such as an E ² PROM in advance. Various signal processing units for performing white balance adjustment, hue adjustment, and the like are provided.

Further, in a video camera, contour enhancement processing is applied to an image pickup signal in order to compensate for deterioration in response of the image pickup device and emphasize sharpness. And
With a color video camera, the skin tone part of the image is detected, contour enhancement processing is performed to reduce the amount of detail in that part, and the frequency characteristics are reduced to reduce wrinkles and stains on the face, thus reducing the appearance of human skin. I try to reproduce it beautifully.

[0006]

By the way, in the conventional contour enhancement processing, since only the frequency characteristic is changed, it is not possible to change even the hue of the flesh color, and the face color looks beautiful or the flesh color is slightly changed. It cannot be processed.

Therefore, the present invention has been made in view of the above circumstances, and a digital signal capable of detecting a specific color portion of a captured image and changing the hue or brightness of the portion. The purpose is to provide a processing camera.

[0008]

In order to solve the above-mentioned problems, the present invention provides a digital signal processing camera which digitizes an image pickup signal, digitally processes the image pickup signal, and outputs the digitalized image pickup signal. Color detection means for detecting color image pickup signals, color correction processing means for performing color correction processing on the digitized image pickup signals, and color correction coefficients for the color correction processing means according to the detection output of the color detection means. It is characterized in that it comprises variable color correction coefficient control means, and performs color correction processing in which the color correction coefficient is changed on an image pickup signal of a specific color.

Further, according to the present invention, in a digital signal processing camera for digitizing an image pickup signal, performing digital processing, and outputting, a color detecting means for detecting an image pickup signal of a specific color in the digitized image pickup signal; A pedestal processing unit that performs pedestal processing on the digitized image pickup signal and a pedestal value control unit that changes the pedestal value of the pedestal processing unit according to the detection output of the color detection unit are provided. On the other hand, the pedestal processing is performed by changing the pedestal value.

Further, according to the present invention, in a digital signal processing camera which digitizes an image pickup signal, digitally processes the image pickup signal, and outputs the digitized image pickup signal, color detecting means for detecting an image pickup signal of a specific color is provided. Level compression / expansion processing means for performing level compression / expansion processing on the digitized image pickup signal, and level compression / expansion processing for varying the level compression / expansion characteristics of the level compression / expansion processing means according to the detection output of the color detection means. It is characterized in that it is provided with expansion characteristic control means, and performs level compression / expansion processing with variable level compression / expansion characteristics on an image pickup signal of a specific color.

Further, the digital signal processing camera according to the present invention is characterized in that the level compression / expansion processing means is a gamma correction means.

The digital signal processing camera according to the present invention is characterized in that the level compression / decompression processing means is a knee correction means.

Further, according to the present invention, in a digital signal processing camera which digitizes an image pickup signal, digitally processes the image pickup signal, and outputs the digitized image pickup signal, color detecting means for detecting an image pickup signal of a specific color, Color correction processing means for performing color correction processing on the digitized image pickup signal, color correction coefficient control means for varying the color correction coefficient of the color correction processing means according to the detection output of the color detection means, and the digitized Pedestal processing means for performing pedestal processing on the image pickup signal, pedestal value control means for changing the pedestal value of the pedestal processing means according to the detection output of the color detection means, and gamma correction processing for the digitized image pickup signal. The gamma correction characteristic of the gamma correction means and the gamma correction means can be changed according to the detection output of the color detection means. Gamma correction characteristic control means, knee correction means for performing knee correction processing on the digitized image pickup signal, and knee correction characteristic control for changing the knee correction characteristic of the knee correction means according to the detection output of the color detection means. Means for digitally processing the image pickup signal of a specific color in which the color correction coefficient, the pedestal value, the gamma correction characteristic, and the knee correction characteristic are changed.

Further, in the digital signal processing camera according to the present invention, the contour enhancement processing means for subjecting the digitized image pickup signal to the contour enhancement processing, and the detail of the contour enhancement processing means according to the detection output of the color detection means. A detail amount control means for varying the amount is provided, and contour enhancement processing with varying detail amount is performed on an image pickup signal of a specific color.

[0015]

In the digital signal processing camera according to the present invention,
With respect to the digitized image pickup signal, the color detection unit detects the image pickup signal of a specific color, and the color correction coefficient control unit varies the color correction coefficient for the image pickup signal of the specific color,
Color correction processing is performed by the color correction processing means.

Further, in the digital signal processing camera according to the present invention, with respect to the digitized image pickup signal, the color detecting means detects the image pickup signal of a specific color, and the pedestal value control means detects the image pickup signal of the specific color. The pedestal value is varied, and the pedestal processing means performs pedestal processing.

Further, in the digital signal processing camera according to the present invention, with respect to the digitized image pickup signal, the color detecting means detects the image pickup signal of a specific color, and the level compression / expansion characteristic is obtained with respect to the image pickup signal of the specific color. The level compression / expansion characteristic is changed by the control means, and the level compression / expansion processing is performed by the level compression / expansion processing means.

In the digital signal processing camera according to the present invention, the level compression / expansion characteristic control means is
Gamma correction processing is performed on the image pickup signal of a specific color.

Further, in the digital signal processing camera according to the present invention, the level compression / expansion characteristic control means is:
Knee correction processing is performed on an image pickup signal of a specific color.

Further, in the digital signal processing camera according to the present invention, with respect to the digitized image pickup signal, the color detection means detects the image pickup signal of a specific color, and the color correction constant is changed with respect to the image pickup signal of the specific color. The color correction processing is performed by the color correction processing means, the pedestal processing that changes the pedestal value is performed by the pedestal processing means, the gamma correction processing that changes the gamma correction characteristics is performed by the gamma correction means, and the knee correction that changes the knee correction characteristics is performed. The process is performed by the knee correction means.

Further, in the digital signal processing camera according to the present invention, the detail amount control means varies the detail amount for the image pickup signal of a specific color, and the contour enhancement processing means performs the contour enhancement processing.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a digital signal processing camera according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a digital signal processing camera according to the present invention, for example, as shown in FIG.

The digital signal processing camera shown in FIG. 1 has an image pickup device such as a CCD image sensor, an amplifier, and an A
An image pickup processing unit 1 including an A / D converter and the like is provided.

The image pickup processing section 1 detects the image pickup light incident through a lens (not shown) by a CCD image sensor.
The primary color image pickup signals R, G, B are converted, and these are converted to, for example, 18
It is A / D converted at a clock rate of MHz and output as digital image pickup signals G, R, B. Here, the CCD image sensor forming the image pickup processing unit 1 is subjected to spatial pixel shift, and the green digital signal G, the red digital signal R, and the blue digital signal B are out of phase with each other by 1/2 pitch. Then, the image pickup processing unit 1 performs A / D conversion on the three primary color image pickup signals R, G, and B while the phases are still deviated, and the digital image pickup signal G,
The R and B are supplied to the preprocessor 2.

The preprocessor 2 corrects the defect of the CCD image sensor constituting the image pickup processing unit 1 and the variation of the sensitivity of the CCD image sensor with respect to the digital image pickup signals G, R and B supplied from the image pickup processing unit 1. Signal processing for correcting shading distortion or the like that affects white and black.

A green image pickup signal G and a red image pickup signal R which have been subjected to shading correction and the like by the preprocessor 2.
Are supplied to the image enhancer 3. The green image pickup signal G is supplied to the color detection section 7 and the digital processing section 8 via the low pass filter 4. Further, the red image pickup signal R and the blue image pickup signal B are supplied to the color detection section 7 and the digital processing section 8 via interpolation filters 5 and 6, respectively.

Based on the green image pickup signal G and the red image pickup signal R supplied from the preprocessor 2, the image enhancer 3 outputs a detail signal of each of the clock rates of 18 MHz and 36 MHz used for the edge enhancement processing. To generate. Then, the detail signal having the clock rate of 18 MHz is supplied to the digital processing unit 8, and the clock rate is 18 MH.
The detail signal of z is supplied to the adder 16 described later.

Here, the green image pickup signal G output from the preprocessor 2 and the red image pickup signal R and the blue image pickup signal B are out of phase with each other by 1/2, and the red image pickup signal is obtained by the interpolation filters 5 and 6. The phases of R and the blue image pickup signal B are matched with the green image pickup signal G. Further, the green image pickup signal G is band-limited by the low-pass filter 4 so as to have the same frequency characteristics as the color image pickup signals R and B.

The color detecting section 7 functions as a color detecting means in the digital signal processing camera according to the present invention, and the digital image pickup signals G, R, and
Detect a specific color for B. Then, the detection output signal of the color detector 7 is supplied to the coefficient controller 9.

The coefficient control section 9 functions as coefficient control means in the digital signal processing camera according to the present invention, and switches various coefficients given by the coefficient generator 10 to the digital processing section 8. Supply.

Further, the digital processing section 8 functions as digital processing means in the digital signal processing camera according to the present invention, and the color correction circuit 11 is provided.
And the process processing circuits 12R, 12G, and 12B, and the digital image pickup signals G, R, and B supplied from the preprocessor 2 are colored as described later on the basis of various coefficients provided by the coefficient generator 10. Various digital processes such as correction process and process process are performed.

The digital image pickup signals G, R and B, which have been subjected to various kinds of digital processing such as process processing by the digital processing section 8, are supplied to the matrix circuit 13.
The matrix circuit 13 produces a luminance signal Y and color difference signals RY and BY from the digital image pickup signals G, R and B. Then, the luminance signal Y formed by the matrix circuit 13 is supplied to the rate converter 14 and the up converter 15. In addition, the color difference signals R-Y,
BY is the rate converter 14 and the encoder 1 described above.
7 are supplied respectively.

The rate converter 14 has a clock rate of 18 MH supplied from the matrix circuit 13.
The z luminance signal Y and the color difference signals RY and BY are set to, for example, 13
_The luminance signal Y and the color difference signals RY and BY that comply with the D1 standard are converted from the clock rate of 0.5 MHz and output from each signal output terminal for VTR.

The clock rate supplied from the matrix circuit 13 to the up converter 15 is 1
The 8 MHz luminance signal Y is converted into a doubled 36 MHz clock rate and supplied to the adder 16. This adder 16
Adds the detail signal with a clock rate of 36 MHz supplied from the image enhancer 3 to the luminance / luminance signal Y. As a result, the adder 16 performs contour enhancement processing on the luminance signal Y having the clock rate of 36 MHz.

The luminance signal Y subjected to the contour enhancement processing by the adder 16 is supplied to the encoder 17.

The encoder 17 encodes the luminance signal Y subjected to the edge enhancement processing and the color difference signals R-Y and B-Y signals from the matrix circuit 13 into a video signal complying with NTSC, for example.

The video signal obtained by the encoder 17 is converted into an analog signal by the D / A converter 18 and is supplied from the signal output terminal to the viewfinder or the like as the monitor video signal S _VF. A converter 19
Is converted back into an analog signal and output as a composite video signal CS or a test video signal from the signal output terminal.

In this embodiment, a color detecting section 7 for detecting a specific color of the digital image pickup signals G, R, B.
Is, for example, as shown in FIG.
0, 21, 22, 23, 24, 25 and AND gate 2
6, 27, 28, 29.

The level comparator 20 has a red level upper limit value DA for which the signal level of the red image pickup signal R indicates a specific color.
When it is lower than TA-R1, the first red detection signal of logic "1" is supplied to the AND gate 26. Further, the level comparator 21 ANDs the second red detection signal of logic “1” when the signal level of the red image pickup signal R is higher than the red level lower limit value DATA (R) 2 indicating a specific color. Supply to the gate 26. Then, the AND gate 26
When both the first and second red detection signals are logic "1", the output becomes logic "1". For example, the red level upper limit value DATA (R) shown by hatching in FIG. The red detection signal indicating the red image pickup signal R having a signal level between 1 and the red level lower limit value DATA (R) 2 by the logic "1" is the above-mentioned AN.
Supply to the D gate 29.

The level comparator 22 outputs the first green detection signal of logic "1" when the signal level of the green image pickup signal G is lower than the green level upper limit value DATA (G) 1 indicating a specific color. It is supplied to the AND gate 27. further,
The level comparator 23 outputs the second green detection signal of logic "1" to the AND gate 27 when the signal level of the green image pickup signal G is higher than the green level upper limit value DATA (G) 2 indicating a specific color. Supply to. The AND gate 27 outputs a logic "1" when both the first and second green detection signals are logic "1".
(B) is shaded and the green detection signal G having a signal level between the green level upper limit value DATA (G) 1 and the green level lower limit value DATA (G) 2 is indicated by logic "1". Signal is the above A
Supply to the ND gate 29.

Further, the level comparator 24 is
When the signal level of the blue image pickup signal B is lower than the blue level upper limit value DATA (B) 1 indicating a specific color, the first blue detection signal of logic "1" is supplied to the AND gate 28. Also,
The level comparator 25 outputs the second blue detection signal of logic "1" to the AND gate 28 when the signal level of the blue image pickup signal B is higher than the blue level lower limit value DATA (B) 2 indicating a specific color. Supply to. The AND gate 28 outputs a logic "1" when both the first and second blue color detection signals are logic "1".
(C) is shaded to indicate a blue detection signal indicating a blue image pickup signal B having a signal level between a blue level upper limit value DATA-B1 and a blue level lower limit value DATA (B) 2 by a logic "1". A above
Supply to the ND gate 29.

The AND gate 29 outputs a logic "1" when the red detection signal, the green detection signal and the blue detection signal are all logic "1", and the red level upper limit value DATA (R) 1. , Red level lower limit DATA (R) 2, Green level upper limit DATA (G) 1, Green level lower limit DATA (G) 2, Blue level upper limit DATA (B) 1 and Blue level lower limit DATA (B) 2 For example, a color detection signal having a logic "1" is output for the area of a specific color defined by, for example, hatched in FIG.

Here, the color detecting section 7 is, for example, as shown in FIG. 5, a luminance signal generator 30, subtractors 31, 32,
Level comparators 33, 34, 35, 36 and AND
It can also be configured with the gate 37.

In the color detecting section 7 shown in FIG. 5, the luminance signal generator 30 generates a luminance signal Y from the color image pickup signals G, R and B. Then, the luminance signal Y is supplied to the subtractors 31 and 32.

The subtractor 31 subtracts the luminance signal Y from the red image pickup signal R to generate a red color difference signal RY. Then, the red color difference signal RY is supplied to the level comparators 33 and 34. Further, the subtractor 32 subtracts the luminance signal Y from the blue image pickup signal B to generate a blue difference signal BY. The blue color difference signal BY is supplied to the level comparators 35 and 36.
Is supplied to.

The level comparator 33 detects the first red difference of logic "1" when the signal level of the red difference signal R-Y is lower than the red difference level upper limit value DATA (RY) 1 indicating a specific color. The signal is supplied to the AND gate 37. In addition, the level comparator 34 is configured such that the signal level of the red color difference signal RY indicates a specific color and the red color difference level upper limit value DATA (R
-Y) The second red difference detection signal of logic "1" is supplied to the AND gate 37 when it is higher than 2. Further, the level comparator 35 outputs the first blue difference detection signal of logic "1" when the signal level of the blue difference signal BY is lower than the blue difference level upper limit value DATA (BY) 1 indicating a specific color. Above A
Supply to the ND gate 37. Further, the level comparator 36 detects the second blue color difference of logic "1" when the signal level of the blue color difference signal BY is higher than the blue color difference level upper limit value DATA (BY) 2 indicating a specific color. AND the signal above
Supply to the gate 37.

In the AND gate 37, the first red color difference detection signal, the second red color difference detection signal, the first blue color difference detection signal and the second blue color difference detection signal are all logic "1". Sometimes the output becomes logic "1" and the above red difference upper limit value DATA (RY) 1, red difference lower limit value DATA (RY) 2, blue difference upper limit value DATA (BY) 1 and blue lower limit value DATA (BY) 2 A color detection signal having a logic "1" is output for a specific color area indicated by hatching in the defined FIG.

Further, in this embodiment, the color correction circuit 11 functions as a color correction processing means in the digital signal processing camera according to the present invention. For example, as shown in FIG. 40 RB, 40
BG, sign inverters 41RG, 41RB, 41BG, multipliers 42a, 42b, 42c, 42d, 42e, 42f and adders 43R, 43G, 43B, 45R, 45G, 45.
B and delay circuits 44R, 44G and 44B.

The subtractor 40RG generates a difference signal R-G indicating the level difference between the red image pickup signal R and the green image pickup signal G. Then, the difference signal RG is supplied to the multiplier 42a.
Is also supplied to the multiplier 42c via the sign inverter 41RG. In addition, the subtractor 40RB
Generates a difference signal RB indicating the level difference between the red image pickup signal R and the green image pickup signal B. Then, this difference signal R
-B is supplied to the multiplier 42b and is also supplied to the multiplier 42e via the sign inverter 41RB. Further, the subtractor 40BG generates a difference signal B-G indicating the level difference between the blue image pickup signal B and the green image pickup signal G.
Then, this difference signal B-G is supplied to the multiplier 42f, and also via the sign inverter 41BG.
supplied to d.

The multiplier 42a is the coefficient generator 1 described above.
Color correction coefficient a ₀ or color correction coefficient a ₁ given by ₀
Are selectively supplied through the coefficient control unit 9, and the difference signal RG generated by the subtractor 40RG is multiplied by the color correction coefficient a ₀ or the color correction coefficient a ₁ . . The multiplication output signal a (R
-G) is supplied to the adder 43R. Further, the multiplier 42b is configured such that the color correction coefficient b ₀ or the color correction coefficient b ₁ given by the coefficient generator 10 is selectively supplied through the coefficient control unit 9, and The difference signal RB generated by the subtractor 40RB is multiplied by the color correction coefficient b ₀ or the color correction coefficient b ₁ . The multiplication output signal b (RB) from the multiplier 42a is supplied to the adder 43R. The adder 43R adds the multiplication output signals a (R-G) and b (R-B), and the added output a (R-G) + b (R-B) is used as a red correction signal to adder 45R. Supply to.

The adder 45R is supplied with the red image pickup signal R via a delay circuit 44R, and the red image pickup signal R is added to the red color correction signal a (RG) + b.
By adding (RB), the color-corrected red image pickup signal R _OUT is generated. The delay circuit 44R is
The red image pickup signal R and the red color correction signal a (RG) + b
Delay compensation with (RB) is performed.

Further, the multiplier 42c is adapted to selectively supply the color correction coefficient c ₀ or the color correction coefficient c ₁ given by the coefficient generator 10 via the coefficient control unit 9. Therefore, the difference signal GR whose sign is inverted by the sign inverter 41RG is multiplied by the color correction coefficient c ₀ or the color correction coefficient c ₁ . The multiplication output signal c (GR) from the multiplier 42c is supplied to the adder 43G. Further, the multiplier 42d is the coefficient generator 10 described above.
The color correction coefficient d ₀ or the color correction coefficient d ₁ given by the above is selectively supplied through the coefficient control section 9, and the difference signal G- whose sign is inverted by the sign inverter 41BG is given. B is multiplied by the color correction coefficient d ₀ or the color correction coefficient d ₁ . The multiplication output signal d (GB) from the multiplier 42d is supplied to the adder 43G. The adder 43G outputs the multiplication output signals c (GR), d.
(G−B) is added, and the addition output c (G−R) + d
(GB) is supplied to the adder 45G as a green correction signal.

The green image pickup signal G is supplied to the adder 45G via the delay circuit 44G, and the green image pickup signal G is added to the green color correction signal c (GR) + d.
By adding (GB), the color-corrected green image pickup signal G _OUT is generated. The delay circuit 44G is
The green image pickup signal G and the green color correction signal c (GR) + d
Delay compensation with (GB) is performed.

Further, the multiplier 42e is adapted to selectively supply the color correction coefficient e ₀ or the color correction coefficient e ₁ given by the coefficient generator 10 via the coefficient control unit 9. Therefore, the difference signal B-R whose sign is inverted by the sign inverter 41RB is multiplied by the color correction coefficient e ₀ or the color correction coefficient e ₁ . The multiplication output signal e (BR) from the multiplier 42e is supplied to the adder 43B. Further, the multiplier 42f is the coefficient generator 10 described above.
The color correction coefficient f ₀ or the color correction coefficient f ₁ given by the above is selectively supplied through the coefficient control section 9, and the difference signal BG generated by the subtractor 40BG is added to the difference signal BG. The color correction coefficient f ₀ or the color correction coefficient f ₁ is multiplied. The multiplication output signal f (B-
G) is supplied to the adder 43B. The adder 4
The 3B adds the multiplication output signals e (B−R) and f (B−G), and supplies the addition output e (B−R) + f (G−B) to the adder 45B as a blue correction signal. .

The blue image pickup signal B is supplied to the adder 45B via the delay circuit 44B, and the blue image pickup signal B is added to the blue color correction signal e (BG) + f.
By adding (BG), the color-corrected blue image pickup signal B _OUT is generated. The delay circuit 44G is
The blue image pickup signal B and the blue correction signal e (B−G) + f
Delay compensation with (B-G) is performed.

Here, the coefficient control section 9 is provided with a changeover switch for controlling the area of the specific color detected by the color detection section 7 in accordance with a color detection signal having a logic "1". When the color detection signal is logic "0", the color correction coefficients a ₀ , b ₀ , c ₀ , d ₀ from the coefficient generator 10 are obtained.
e ₀ , f ₀ are selected, and when the color detection signal is logic “1”, each color correction coefficient a ₁ , from the coefficient generator 10 is
b ₁ , c ₁ , d ₁ , e ₁ , and f ₁ are selected.

As a result, the color correction circuit 11 sets the color correction coefficients a ₀ , b ₀ , c ₀ , d ₀ , for the digital image pickup signals R, G, B in the normal region other than the specific color.
After performing color correction processing with e ₀ and f ₀ , R _OUT = R + a ₀ (R−G) + b ₀ (R−B) G _OUT = G + c ₀ (G−R) + d ₀ (G−B) B _OUT = B + e ₀ (B−R) + f ₀ (B−G), which are color-corrected image pickup signals R _OUT , G _OUT , and B _OUT are generated.

In the area of a specific color, the color correction coefficient
a₁, B₁, C₁, D₁, E₁, F ₁Color correction processing by
Go to R_OUT= R + a₁(R-G) + b₁(RB) G_OUT= G + c₁(GR) + d₁(GB) B_OUT= B + e₁(BR) + f₁(B-G) each color-corrected image pickup signal R_OUT, G_OUT, B_OUTTo
To generate.

Therefore, the color correction circuit 11 having such a configuration is used.
Then, by performing color correction processing by changing the color correction coefficient, it is possible to perform optimum color correction processing on a specific color (for example, skin color) area, and to reproduce that color more beautifully. Become.

Further, in this embodiment, the process processing circuit 12R includes the adder 5 as shown in FIG.
1R, 52R, 55R, a gamma correction circuit 53R, a knee correction circuit 53R, and a multiplier 56R. In addition,
Each of the other process processing circuits 12G and 12B is composed of an adder, a gamma correction circuit, a knee correction circuit, and a multiplier, like the above-mentioned process processing circuit 12R, and performs the same process processing.

In the process processing circuit 12R shown in FIG. 8, the adder 51R functions as pedestal processing means in the digital signal processing camera according to the present invention, and is the first provided by the coefficient generator 10 described above.
The pedestal value Ped ₀ or the second pedestal value Ped ₁ is selectively supplied via the coefficient control unit 9. This adder 51R has the above-mentioned first pedestal value Pe.
By adding d ₀ or the second pedestal value Ped ₁ ,
The red image pickup signal R color-corrected by the color correction circuit 11 is pedestal-processed.

Here, the coefficient control section 9 is controlled by a changeover switch which is controlled according to the color detection signal from the color detection section 7 so that the first pedestal value Ped ₀ and the second pedestal value Ped _{1 are obtained.} Is selected, and the first pedestal value Ped ₀ is selected in a region other than the specific color in which the color detection signal is logical “0”, and the specific color in which the color detection signal is logical “1” is selected. In the region of, the above second pedestal value Ped ₁
Is to be selected.

As a result, the adder 51R adds the first pedestal value Ped ₀ = + a to the red image pickup signal R in the area other than the specific color, as shown in FIG. 9, for example.
A pedestal process of adding the second pedestal value Ped ₁ = −a is performed on the red image pickup signal R of the specific color region.

As described above, by performing the pedestal process by changing the pedestal value with respect to the region of a specific color (for example, the skin color) to obtain the optimum pedestal, the color can be reproduced more beautifully.

The adders 51R and 55R function as contour correction processing means in the digital signal processing camera according to the present invention, and the detail signal is supplied from the image enhancer 3 via the multiplier 56R. . The multiplier 56R is selectively supplied with the first contour correction coefficient Gain ₀ or the second contour correction coefficient Gain ₁ provided by the coefficient generator 10 via the coefficient control unit 9. Has become.

Here, the coefficient control section 9 selects the first contour correction coefficient Gain ₀ and the second contour correction coefficient Gain ₁ by the changeover switch which is controlled to change according to the color detection signal, The first contour correction coefficient Gain ₀ is selected in an area other than the specific color where the color detection signal is logical "0", and the first contour correction coefficient Gain ₀ is selected in the area of the specific color where the color detection signal is logical "1". The second contour correction coefficient Gain ₁ is selected.

As a result, the multiplier 56R multiplies the detail signal for the red image pickup signal R in the area other than the specific color by the first contour correction coefficient Gain _0, and the red image pickup signal in the area of the specific color. The detail signal for R is multiplied by the second contour correction coefficient Gain ₁ . The adders 51R and 55R add contour signals weighted by the first contour correction coefficient Gain ₀ to perform contour correction processing on the red image pickup signal R in a region other than the specific color, and The detail correction signal weighted by the second contour correction coefficient Gain ₁ is added to the red image pickup signal R of the region of the specific color to thereby perform the contour correction process on the red image pickup signal R of the region other than the specific color. Give.

As described above, by performing contour correction processing by changing the contour correction coefficient for a region of a specific color (for example, skin color), it becomes possible to reproduce the color more beautifully.

The gamma correction circuit 53R and the knee correction circuit 54R function as level compression / expansion processing means in the digital signal processing camera according to the present invention.

The gamma correction circuit 53R has a first gamma correction coefficient γ provided by the coefficient generator 10 described above.
_{The 0} or the second gamma correction coefficient γ ₁ is selectively supplied via the coefficient control unit 9. In addition, the knee correction circuit 54R includes a first coefficient Slope ₀ , Point ₀ indicating a first knee slope and a knee point provided by the coefficient generator 10 or a second coefficient Slope ₀ , Point ₀ indicating a second knee slope and a knee point. The coefficients Slope ₁ and Point ₁ of the above are selectively supplied through the coefficient control unit 9.

Here, the coefficient control section 9 selects the first gamma correction coefficient γ ₀ and the second gamma correction coefficient γ ₁ by a changeover switch which is controlled to change according to the color detection signal, The first gamma correction coefficient γ ₀ is selected in a region other than the specific color in which the color detection signal is logical “0”, and the first gamma correction coefficient γ ₀ is selected in the region of the specific color in which the color detection signal is logical “1”. The second gamma correction coefficient γ ₁ is selected.

As a result, the gamma correction circuit 53R
On the basis of the first gamma correction coefficient γ ₀ , a normal gamma characteristic (γ = 0.
The gamma correction process of 5) is performed on the red image pickup signal R in the area other than the specific color, and based on the second gamma correction coefficient γ ₁ , the gamma characteristic (γ = The gamma correction process of 0.4) is applied to the red image pickup signal R of the specific color area. The gamma characteristic for the red image pickup signal R in the specific color area is not limited to the gamma characteristic (γ = 0.4) shown by the broken line in FIG. 10, but is shown by a chain line in FIG. 10, for example. Gamma characteristic (γ =
It can be arbitrarily set, for example, to 0.6).

By changing the gamma correction coefficient in this way, it is possible to perform the gamma correction processing of the optimum gamma characteristic on the image pickup signal of the region of a specific color (for example, skin color), and reproduce the color more beautifully. It will be possible.

Further, the coefficient control section 9 uses the changeover switch, which is controlled to change in accordance with the color detection signal, by the first switch.
Of the coefficients Slope ₀ , Point ₀ and the second coefficients Slope ₁ , Point ₁ are selected, and the first coefficients Slope ₀ , Point ₀ are set in the area other than the specific color where the color detection signal becomes logical "0". Is selected, and the second coefficient Slope ₁ and Point ₁ are selected in the area of the specific color where the color detection signal becomes logic "1".

As a result, the knee correction circuit 54R is
Based on the first coefficients Slope ₀ and Point ₀ , for example, the knee correction process of the normal knee characteristic as shown by the solid line in FIG. 11 is performed on the red image pickup signal R in the area other than the specific color, and
Based on the second coefficients Slope ₁ and Point ₁ , for example, FIG.
A knee correction process having a knee characteristic as indicated by a broken line in FIG. 1 is performed on the red image pickup signal R in the specific color region.

By changing the knee correction coefficient in this way, it is possible to perform a knee correction process having an optimum knee characteristic on an image pickup signal of a region of a specific color (for example, skin color), and reproduce the color more beautifully. It will be possible.

[0078]

In the digital signal processing camera according to the present invention, the color detection means detects the image pickup signal of a specific color from the digitized image pickup signal, and the color correction coefficient control means is provided for the image pickup signal of the specific color. Since the color correction coefficient is varied by means of this and the color correction processing is carried out by the color correction processing means, the optimum color correction processing can be carried out on the image pickup signal of the region of a specific color.

Further, in the digital signal processing camera according to the present invention, with respect to the digitized image pickup signal, the image pickup signal of the specific color is detected by the color detecting means, and the pedestal value control means is used for the image pickup signal of the specific color. Since the pedestal processing is performed by changing the pedestal value and the pedestal processing means, it is possible to change the brightness with the pedestal of the image pickup signal of the region of the specific color as an optimum value.

Further, in the digital signal processing camera according to the present invention, with respect to the digitized image pickup signal, the color detecting means detects the image pickup signal of the specific color, and the level compression / expansion characteristic is obtained with respect to the image pickup signal of the specific color. The level compression / expansion characteristics can be changed by the control means, and the level compression / expansion processing means can perform the level compression / expansion processing in which the gamma correction characteristics and knee correction characteristics are optimally set to change the brightness.

Further, in the digital signal processing camera according to the present invention, with respect to the digitized image pickup signal, the color detection means detects the image pickup signal of a specific color, and the color correction coefficient is changed with respect to the image pickup signal of the specific color. The color correction processing is performed by the color correction processing means, the pedestal processing that changes the pedestal value is performed by the pedestal processing means, the gamma correction processing that changes the gamma correction characteristics is performed by the gamma correction means, and the knee correction that changes the knee correction characteristics is performed. Since the processing is performed by the knee correction means, the detail amount is changed by the detail amount control means, and the contour enhancement processing is performed by the contour enhancement processing means, the optimum characteristics are set for the image pickup signal of the specific color area, and the color is set. Correction processing, pedestal processing, gamma correction processing, knee correction processing, and edge enhancement processing can be performed, and the colors are made more beautiful. Ku it is possible to reproduce.

[Brief description of drawings]

FIG. 1 is a block circuit diagram showing a configuration of a digital signal processing camera according to the present invention.

FIG. 2 is a block circuit diagram showing a specific configuration example of a color detection unit in the digital signal processing camera.

FIG. 3 is a characteristic diagram for explaining the operation of the color detection unit.

FIG. 4 is a diagram showing a color detection signal by the color detection unit.

FIG. 5 is a block circuit diagram showing another specific configuration example of the color detection unit in the digital signal processing camera.

FIG. 6 is a characteristic diagram for explaining the operation of the color detection unit.

FIG. 7 is a block circuit diagram showing a specific configuration example of a color correction circuit of a digital arithmetic unit in the digital signal processing camera.

FIG. 8 is a block circuit diagram showing a specific configuration example of a process processing circuit of a digital arithmetic unit in the digital signal processing camera.

FIG. 9 is a waveform diagram for explaining an operation of a pedestal process in the process processing circuit.

FIG. 10 is a characteristic diagram for explaining the operation of gamma correction processing in the process processing circuit.

FIG. 11 is a characteristic diagram for explaining the operation of knee correction processing in the process processing circuit.

[Explanation of symbols]

 Image processing unit 2 Preprocessor 3 Image enhancer 7・ ・ ・ ・ ・ ・ ・ ・ Color detection unit 8 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Digital operation unit 9 ・ ・ ・ ・ ・ ・ ・ ・ ・ Coefficient control unit 10 ・ ・ ・ ・ ・ ・--- Coefficient generator 11 --------- Color correction circuit 12R, 12G, 12B --- Process processing circuit 51, 52, 55 ---- Adder 53・ ・ ・ ・ ・ ・ ・ ・ ・ Gamma correction circuit 54 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Knee correction circuit

Claims (7)

[Claims] 1. A digital signal processing camera for digitizing an image pickup signal, performing digital processing, and outputting the digitized image pickup signal. Color detection means for detecting an image pickup signal of a specific color in the digitized image pickup signal, and the digitized image pickup. A color correction processing means for performing color correction processing on the signal, and a color correction coefficient control means for varying the color correction coefficient of the color correction processing means according to the detection output of the color detection means On the other hand, a digital signal processing camera, which performs color correction processing with variable color correction coefficients. 2. A digital signal processing camera for digitizing an image pickup signal, performing digital processing, and outputting the digitized image pickup signal. Color detection means for detecting an image pickup signal of a specific color in the digitized image pickup signal; and the digitized image pickup. The pedestal processing means for subjecting the signal to pedestal processing and the pedestal value control means for varying the pedestal value of the pedestal processing means according to the detection output of the color detection means are provided, and the pedestal for the imaging signal of a specific color is provided. A digital signal processing camera characterized by performing pedestal processing with variable values. 3. A digital signal processing camera for digitizing an image pickup signal, performing digital processing, and outputting the digitized image pickup signal. Color detection means for detecting an image pickup signal of a specific color in the digitized image pickup signal; and the digitized image pickup. Level compression / expansion processing means for subjecting the signal to level compression / expansion processing, and level compression / expansion characteristic control means for varying the level compression / expansion characteristics of the level compression / expansion processing means in accordance with the detection output of the color detection means. A digital signal processing camera, comprising: and a level compression / expansion process with variable level compression / expansion characteristics for an image signal of a specific color. 4. The digital signal processing camera according to claim 3, wherein the level compression / decompression processing means is gamma correction means. 5. The digital signal processing camera according to claim 3, wherein the level compression / decompression processing means is a knee correction means. 6. A digital signal processing camera for digitizing an image pickup signal, performing digital processing, and outputting the digitized image pickup signal. Color detection means for detecting an image pickup signal of a specific color in the digitized image pickup signal; and the digitized image pickup. Color correction processing means for performing color correction processing on the signal, color correction coefficient control means for changing the color correction coefficient of the color correction processing means according to the detection output of the color detection means, and pedestal for the digitized image pickup signal. Pedestal processing means for performing processing, pedestal value control means for varying the pedestal value of the pedestal processing means according to the detection output of the color detection means, and gamma correction means for performing gamma correction processing on the digitized image pickup signal. , A gamma for varying the gamma correction characteristic of the gamma correction means according to the detection output of the color detection means. Positive characteristic control means, knee correction means for performing knee correction processing on the digitized image pickup signal, and knee correction characteristic control means for varying the knee correction characteristic of the knee correction means according to the detection output of the color detection means. A digital signal processing camera characterized by including digital processing in which a color correction coefficient, a pedestal value, a gamma correction characteristic, and a knee correction characteristic are varied with respect to an image pickup signal of a specific color. 7. A contour enhancement processing means for subjecting the digitized image pickup signal to a contour enhancement processing, and a detail amount control means for varying a detail amount of the contour enhancement processing means according to a detection output of the color detection means. 7. The digital signal processing camera according to claim 6, further comprising: an edge enhancement process in which a detail amount is varied, for an image pickup signal of a specific color.