JP3418566B2 - Video 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 pickup apparatus such as a video camera, and more particularly to a video signal processing apparatus which reproduces each color more beautifully by setting optimum processing characteristics according to hue.

[0002]

2. Description of the Related Art Generally, video signals handled by an image pickup device such as a color video camera are subjected to various signal processing such as gamma correction, contour correction, white balance adjustment, color gain adjustment, and hue adjustment.

For example, in the case of a color video camera, CC
An image pickup signal processing circuit that forms and outputs a luminance signal and a color signal from an image pickup signal obtained by an image pickup unit using a D image sensor or the like, in the gamma correction, contour correction, white balance adjustment, color gain adjustment, hue adjustment, etc. Are configured to be subjected to various kinds of signal processing. Then, in a digital signal processing camera that digitizes an image pickup signal, performs digital processing, and outputs,
Various signal processing units for performing the gamma correction, the contour correction, the white balance adjustment, the color gain adjustment, the hue adjustment, and the like based on the control parameters written in the nonvolatile memory such as the ROM are provided.

Further, in a color video camera, a skin-colored portion of an image is detected, contour enhancement processing is performed to reduce the amount of detail in that portion, and the frequency characteristics are reduced to remove wrinkles and stains on the face. , Processed to reproduce human skin beautifully. However, in the above-described contour enhancement processing, since only the frequency characteristic is changed, even the hue of the flesh color cannot be changed, and the processing such as making the face color look beautiful or slightly changing the flesh color cannot be performed. As a method for solving this problem, the method described in Japanese Patent Laid-Open No. 6-141337 has been proposed. In the digital signal processing camera described in this publication, a specific color (for example, skin color) part of a captured image is detected, and the hue or brightness of the part is changed to reproduce the specific color more beautifully. ing.

FIG. 17 is a block diagram showing an example of the main configuration of a conventional color video camera. In this figure, the image pickup signal from the image pickup device 81 is a low-pass filter (L
The luminance signal is input to the PF) 82, and the luminance signal is extracted. The luminance signal is sent to the encoder 94 via the luminance signal gain adjustment circuit 83 and the luminance signal gamma correction circuit 84. The image pickup signal from the image pickup device 81 is sent to the color separation circuit 85, where R,
The G and B signals are separated. The separated R, G, and B signals are sent to the R signal gain adjusting circuit 86, the G signal gain adjusting circuit 87, and the B signal gain adjusting circuit 88, respectively. These signals are further sent to a matrix circuit 92 via an R gamma correction circuit 89, a G gamma correction circuit 90, and a B gamma correction circuit 91, respectively, where the R, G, B signals are color difference signals (R -Y) and (BY) signals are generated. The (R-Y) signal and the (B-Y) signal are corrected by the color reproduction correction circuit 93, then supplied to the encoder 94, and processed together with the luminance signal output from the luminance signal gamma correction circuit 84 to form a composite image. Become a signal.

In a color television system, there is an ideal spectral characteristic for obtaining an ideal R, G, B signal depending on the system, and color reproduction is performed by using an image pickup device using a color filter based on the ideal spectral characteristic. No correction circuit is required.
However, it is difficult to realize ideal spectral characteristics, so
The R, G, B signals at the output of the color separation circuit 85 include an error, and therefore the (RY) signal at the output of the matrix circuit 92 and
The (BY) signal will also include an error. The color reproduction correction circuit 93 corrects so as to reduce this error.

The conventional color reproduction correction is expressed by the following equation [1],
[2] and is described in JP-A-5-161152. (R−Y) ′ = (R−Y) + Gb · (B−Y)… [1] (B−Y) ′ ＝ (B−Y) + Gr · (R−Y)… [2]

Here, (R-Y) 'and (B-Y)' are the corrected (R-Y) '.
Y) and (BY). Further, Gr and Gb are constants for determining the gain, and are changed in two steps as follows depending on the magnitude of the (RY) signal or the (BY) signal, for example. If (R−Y) ≧ Vrr, Gr = Gr1 (R−Y) <Vrr, Gr = Gr2 (B−Y) ≧ Vrb, Gb = Gb1 (B−Y) <Vrb, Gb = Gb2

Here, Vrr is a first reference value and Vrb is a second reference value. In essence, the value of Gr can be changed by the magnitude of the (RY) signal.
Switch to 1 and Gr2 and change the Gb value to Gb1 and Gb depending on the magnitude of the (B-Y) signal.
Switch to b2.

FIG. 18 is a block diagram of an embodiment described in Japanese Patent Laid-Open No. 5-161152. As shown in this figure, the first comparison unit 101 compares the input (RY) signal with the first reference value Vrr. The second comparison unit 102 compares the input (BY) signal with the second reference value Vrb. The first gain switching unit 103 receives the output of the first comparison unit 101,
The first gain constant Gr1 or the second gain constant Gr2 is switched. The second gain switching unit 104 switches the third gain constant Gb1 or the fourth gain constant Gb2 according to the output of the second comparison unit 102. The first multiplication unit 105 multiplies any of the gain constants selected by the first gain switching unit 103 by the (RY) signal. The second multiplication unit 106 multiplies any of the gain constants selected by the second gain switching unit 104 by the (BY) signal. The first adder 107 is configured to add the (RY) signal to the second multiplier 106.
And the output of. The second addition unit 108 adds the (BY) signal and the output of the first multiplication unit 105. In this configuration, the corrected signal (R−Y) ′ of the above formula [1] is output to the output of the first adder 107, and the corrected signal (B−B of the formula [2] is output to the output of the second adder 108. Y) 'is output.

The operation of this circuit will be described below with reference to FIG. 16, which is a vector diagram when a color bar chart is imaged. Here, for convenience, the first reference value Vrr will be described as 0, and the second reference value Vrb will also be described as 0. In practice, each reference value uses an optimum value so that a good vector can be obtained.

First, it is assumed that Gr ≠ 0 and Gb = 0. Red is (R-Y)
Since> 0, (R−Y) ′ = (R−Y) (B−Y) ′ = (B−Y) + Gr1 · (R−Y) Since cyan is (R−Y) <0, (R-Y) '= (R-Y) (B-Y)' = (B-Y) + Gr2 ・ (R-Y)

Therefore, the phase of red can be adjusted by changing the value of Gr1, and the phase of cyan can be adjusted by changing the value of Gr2.
-The phase can be changed in the direction parallel to the (Y) axis.
At this time, yellow and blue are not affected because the level of the (RY) signal is small.

Next, it is assumed that Gr = 0 and Gb ≠ 0. Yellow is (B-Y)
Since <0, (R−Y) ′ = (R−Y) + Gb2 · (B−Y) (B−Y) ′ = (B−Y) Since blue is (B−Y)> 0, (R-Y) '= (R-Y) + Gb1 · (B-Y) (B-Y)' = (B-Y)

Therefore, it is possible to adjust the yellow phase by changing the value of Gb2 and the blue phase by changing the value of Gb1. Therefore, as shown in FIG. 19, the phase can be changed in the direction of the arrow, that is, in the direction parallel to the (RY) axis. At this time, red and cyan are not affected because the (BY) signal is small.

[0016]

However, the above-mentioned conventional digital signal processing camera disclosed in Japanese Unexamined Patent Publication No. 6-141337 only extracts a specific color, so that image quality correction such as color reproduction correction is specified. When applying to a color other than the color, the same correction is performed except for the specific color, and thus accurate image quality correction such as color reproduction correction cannot be performed.

Further, in the color reproduction correction circuit described in the above-mentioned Japanese Patent Laid-Open No. 5-161152, the degree of freedom of color reproduction correction is increased to perform red / cyan color reproduction correction and yellow / blue color reproduction correction. It is only possible to perform the correction independently. For example, as shown in FIG. 19, when it is attempted to correct only magenta, the correction also affects red, so magenta and red cannot be corrected separately, so accurate colors cannot be corrected. There was a problem that reproduction correction could not be performed.

The present invention has been made in order to solve the above conventional problems, and an object thereof is to provide a video signal processing device capable of freely and more accurately adjusting the image quality of a color region to be adjusted. To do.

[0019]

A video signal processing apparatus according to the present invention
The position of a device
Hue determining means for determining the hue from the video signal in the area units classified by straight number, a color reproduction correction means for performing color reproduction correction to the video signal, the color reproduction according to the determination output of the hue judging means And a color reproduction correction coefficient control means for changing the color reproduction correction coefficient of the correction means, and performing a color reproduction correction according to the hue on the video signal .
The hue of the hue determined by the hue determination means
Determine the distance from multiple straight lines and
It is characterized in that the color reproduction correction of the color reproduction correction means is stopped . With this configuration, it is possible to perform optimum color reproduction correction on the video signal according to the hue and reproduce each color more beautifully.

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The invention described in claim 1 of the present invention includes a plurality of intersecting objects set on a color vector diagram.
The hue discrimination means for discriminating the hue from the video signal in units of areas divided by the straight line, the color reproduction correction means for performing the color reproduction correction on the video signal, and the color reproduction correction according to the discrimination output of the hue discrimination means. and a color reproduction correction coefficient control means for changing the color reproduction correction coefficient means, video signal processing apparatus der performing color reproduction correction corresponding to the color on the video signal
The hue discriminator discriminated by the hue discriminator.
The distance from the straight line of the number is determined, and the
A video signal processing device that stops the color reproduction correction of the color reproduction correction means and is divided by a plurality of straight lines that intersect each other.
If you apply independent color reproduction correction to the video signal for each area,
Also, the distance from the above-mentioned plurality of straight lines of the above-mentioned determined hue
Color reproduction correction is stopped according to the result of
Has the effect of preventing

[0026]

[0027]

[0028]

[0029]

[0030]

[0031]

The invention according to claim 2 of the present invention is a video
A hue discriminating means for discriminating the hue from the signal, and the video signal
Color reproduction correction means for performing color reproduction correction on the
Color reproduction correction of the color reproduction correction means according to the discriminating output of the step
Color reproduction correction coefficient control means for changing the coefficient,
A video signal that applies color reproduction correction to the video signal according to the hue.
A No. processor, the hue determination unit includes a first comparator for comparing the first color difference signal input and a first reference value,
A signal for switching a plurality of gain constants by a second comparing section that compares the second color difference signal input with a second reference value, and an output of the first comparing section and an output of the second comparing section. And a first and second gain switching section for switching and outputting any one of a plurality of gain constants by the output of the gain selection signal generating section, and the first color difference signal input. And a first multiplication unit that multiplies the output of the first gain switching unit with each other, and a second multiplication unit that multiplies the second color difference signal input and the output of the second gain switching unit.
The output of the first multiplying unit is the output of the third comparing unit that compares the first color difference signal input and the second color difference signal input with a third reference value, and the output of the third comparing unit. And a second control unit for controlling the output of the second multiplication unit by the output of the third comparison unit, the first color difference signal input and the second control unit for controlling the output of the second multiplication unit. The output of the control unit is added to obtain a first correction output, and the second color difference signal input and the output of the first control unit are added to obtain a second correction output. A video signal processing device having a second adding unit for obtaining, and identifying where in the area divided by the first and second color difference signal axes the hue of the image exists, and independently for each divided area. The reproduced color correction is applied to the video signal, and the hue of the video image is separated from the first and second color difference signal axes by a distance equal to or less than the third reference value. When in has the effect of stopping the color reproduction correction.

The invention described in claim 3 of the present invention is a video
A hue discriminating means for discriminating the hue from the signal, and the video signal
Color reproduction correction means for performing color reproduction correction on the
Color reproduction correction of the color reproduction correction means according to the discriminating output of the step
Color reproduction correction coefficient control means for changing the coefficient,
A video signal that applies color reproduction correction to the video signal according to the hue.
A No. processor, the hue determination unit includes a first comparator for comparing the first color difference signal input and a first reference value,
A second comparing section for comparing the second color difference signal input with a second reference value; a third comparing section for comparing the first color difference signal input with the second color difference signal input; First, second,
A gain selection signal generation unit that generates a signal for switching a plurality of gain constants by the output of the third comparison unit, and outputs one of the plurality of gain constants by switching the output signal of the gain selection signal generation unit. First and second gain switching units, a first multiplication unit that multiplies the first color difference signal input and the output of the first gain switching unit, the second color difference signal input, and the second color difference signal input. A second multiplication unit that multiplies the output of the gain switching unit, and a first addition unit that adds the first color difference signal input and the output of the upper second multiplication unit to obtain a first corrected output. , A second addition unit that adds the second color difference signal input and the output of the first multiplication unit to obtain a second corrected output, wherein the hue of the image is first. , Where in the area divided by the second color difference signal axis and the first and second straight lines To the or identifies, has the effect of applying the video signal independent color reproduction correction for each region to be partitioned.

The invention according to claim 4 of the present invention is a video
A hue discriminating means for discriminating the hue from the signal, and the video signal
Color reproduction correction means for performing color reproduction correction on the
Color reproduction correction of the color reproduction correction means according to the discriminating output of the step
Color reproduction correction coefficient control means for changing the coefficient,
A video signal that applies color reproduction correction to the video signal according to the hue.
A No. processor, the hue determination unit includes a first comparator for comparing the first color difference signal input and a first reference value,
A second comparing section for comparing the second color difference signal input with a second reference value; a third comparing section for comparing the first color difference signal input and the second color difference signal input; A gain selection signal generation unit that generates a signal that switches a plurality of gain constants by the outputs of the second and third comparison units, and an output of the gain selection signal generation unit that switches and outputs one of the gain constants. First and second gain switching units, a first multiplying unit that multiplies the first color difference signal input and the output of the first gain switching unit, the second color difference signal input, and the second A second multiplication unit for multiplying the output of the second gain switching unit;
A fourth comparing unit that compares a difference between the first color difference signal input and the second color difference signal input with a third reference value; and the fourth comparison unit.
By the output of the comparison unit, the first control unit that controls the output of the first multiplication unit, and the output of the fourth comparison unit,
A second controller that controls the output of the second multiplier, the first color difference signal input, and the output of the second controller are added to obtain a first corrected output. Part and the second above
The color difference signal input of and the output of the first control unit are added,
A video signal processing device having a second addition section for obtaining a second corrected output, in which region of the area where the hue of the video is divided by the first and second color difference signal axes and the first and second straight lines. It is discriminated whether or not it exists, and independent color reproduction correction is applied to each divided area on the video signal, and the hue of the video is determined from the first and second color difference signal axes or from the first and second straight lines to the third.
When the distance is equal to or less than the reference value of, the color reproduction correction is stopped.

[0035]

[0036]

[0037]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the image pickup apparatus according to the embodiment of the present invention.

In this image pickup apparatus, the image pickup element 1 is a CC
A D image sensor or the like, which picks up an image of a subject and generates an image pickup signal. The low-pass filter 2 separates the luminance signal from the output signal of the image sensor 1. The luminance signal processing unit 3 performs corrections such as gain adjustment, gamma correction, contour enhancement correction, and pedestal correction on the luminance signal separated by the low pass filter 2. The color signal processing unit 4 separates R, G, and B signals from the output of the image sensor 1, performs matrix calculation processing,
Corrections such as gamma correction, gain correction, and color reproduction correction are performed. The hue discriminating unit 5 discriminates the hue of the image from the color signals {for example, (RY) signal, (BY) signal} generated by the color signal processing unit 4. The coefficient generator 7 generates coefficients for setting various processing characteristics of the color signal processor 4 and the luminance signal processor 3. The coefficient control unit 6 switches various coefficients given from the coefficient generation unit 7 according to the hue discrimination information of the hue discrimination unit 5 and supplies the luminance signal processing unit 3 and the color signal processing unit 4 with the coefficients according to the hue of the subject.

The output control section 8 processes the recording of the luminance signal output from the luminance signal processing section 3 and the color signal output from the color signal processing section 4 on the recording medium 10 and the transmission section 11.
Perform processing for transmission to the outside via the. The control unit 9 controls the output timing of the output control unit 8 and various parameters in output processing. The control unit 9 is composed of, for example, a microcomputer and, if necessary, peripheral circuits such as RAM and ROM. Note that the control unit 9 may be configured to perform some or all of the signal processing performed by the output control unit 8. Further, in the control unit 9, J
Image compression such as PEG may be performed by software processing.

As the recording medium 10, it is preferable to use a semiconductor memory such as a flash memory.
A rewritable magnetic disk, magnetic tape, optical disk, or the like may be used. Furthermore, like a memory card,
A recording medium capable of reading the data in the memory with an external device such as a personal computer may be used. Transmission unit
11 can transmit images to an external personal computer or the like by Ethernet or IEEE1394. Input / output of video signal data among the output control unit 8, the control unit 9, and the recording medium 10 is performed via the bus 12.

As described above, in the image pickup apparatus according to the present embodiment, the color reproduction correction in the color signal processing unit 4, the pedestal processing in the luminance signal processing unit 3, according to the hue determined by the hue determining unit 5, Since gamma correction processing, knee correction processing, contour enhancement processing, and the like can be performed, each color can be reproduced more beautifully. Further, it has a function of generating a luminance signal and a color signal from an image pickup signal output from the image pickup element 1 and recording them on a recording medium 10 or inputting them to a personal computer or the like via a transmission section 11. It is easy to use.

Next, the color reproduction correction of the color signal processing unit 4, the hue discrimination unit 5, the coefficient control unit 6, and the coefficient generation unit 7 in FIG. 1 will be described. Here, the first to fourth color reproduction corrections will be sequentially described.

(First Color Reproduction Correction Circuit) In the first color reproduction correction circuit, it is 4 depending on the size of the (RY) signal and the (BY) signal.
The hue condition, that is, the hue of the image is the two (R−Y) axes and (B) that are two straight lines that intersect each other set on the color vector diagram.
The color reproduction correction coefficient is switched according to the four hue conditions by identifying which one of the first to fourth quadrants that is divided by the (-Y) axis belongs to.

The first color reproduction correction circuit has the following equation [3],
The correction represented by [4] is performed. (RY) '= (RY) + Gb' (BY) ... [3] (BY) '= (BY) + Gr' (RY) ... [4]

Here, Gr 'and Gb' are constants for determining the gain, and change as follows depending on the magnitude of the (RY) signal and the (BY) signal. If (R−Y) ≧ Vrr and (B−Y) ≧ Vrb, Gr '= Gr1 and Gb' = G
If b1 (R−Y) ≧ Vrr and (B−Y) <Vrb, then Gr '= Gr2 and Gb' = G
If b2 (R−Y) <Vrr and (B−Y) <Vrb, then Gr '= Gr3 and Gb' = G
If b3 (R−Y) <Vrr and (B−Y) ≧ Vrb, then Gr '= Gr4 and Gb' = G
b4

Here, Vrr is the first reference value and Vrb is the second reference value. In short, the four hue conditions are identified by the magnitudes of the (RY) signal and the (BY) signal, and the values of Gr 'and Gb' are switched according to the four hue conditions.

FIG. 2 is a block diagram showing the configuration of the first color reproduction correction circuit. In this color reproduction correction circuit, the first comparison unit 21 converts the (RY) signal, which is the first color difference signal, into the first signal.
The second comparison unit 22 compares the (BY) signal, which is the second color difference signal, with the second reference value Vrb. These comparison units 21 and 22 correspond to the hue determination unit 5 in FIG.
The first gain switching unit 24 includes first to fourth gain coefficients Gr1 to Gr4.
Is input, and one of them is selected and output. Similarly,
The second gain switching unit 25 includes the fifth to eighth gain coefficients Gb1 to Gb4.
Is input, and one of them is selected and output. The gain selection signal generation unit 23 generates four types of gain selection signals according to the above conditions by the outputs of the first comparison unit 21 and the second comparison unit 22, and the first and second gain switching units 24 , Supply to 25. The first and second gain switching units 24 and 25 and the gain selection signal generation unit 23 correspond to the coefficient control unit 6 of FIG. The first multiplication unit 26 multiplies any of the gain constants selected by the first gain switching unit 24 by the (RY) signal. The second multiplication unit 27 multiplies any of the gain constants selected by the second gain switching unit 25 by the (BY) signal. First adder 28
Adds (RY) and the output of the second multiplication unit 27. Second
The addition unit 29 of (B−Y) adds the output of the first multiplication unit 26. These multiplication units 26 and 27 and addition units 28 and 29 correspond to the color signal processing unit 4 of FIG. The first addition unit 28 outputs a (R−Y) ′ signal which is the first color difference signal subjected to color reproduction correction,
The second addition unit 29 outputs the (BY) signal which is the second color difference signal subjected to color reproduction correction.

Next, the operation of this color reproduction correction circuit will be described below with reference to FIG. 3, which is a color vector diagram when a color bar chart is imaged. Here, for convenience, the first
The reference value Vrr of 0 will be described as 0, and the second reference value Vrb will also be described as 0. In practice, each reference value uses an optimum value so that a good vector can be obtained.

First, assuming that Gr ≠ 0 and Gb = 0, for example, in FIG.
A description will be given by taking red and magenta existing in the first and second quadrants {(R−Y) ≧ 0} of the above as an example.

Since red has (RY)> 0 and (BY) <0, (R−Y) ′ = (R−Y) ... [5] (B−Y) ′ = (B−Y) + Gr2 · (R−Y) ... [6] And magenta has (R−Y)> 0 and (B−Y)> 0. (R−Y) ′ = (R−Y) ... [7] (B−Y) ′ = (B−Y) + Gr1 · (R−Y) ... [8] Is.

Therefore, the phase of red can be adjusted by changing the value of Gr2, and the phase of magenta can be adjusted by changing the value of Gr1. At this time, the red phase and the magenta phase are corrected in the direction parallel to the (BY) axis in FIG.

In the above case, Gb = 0, but
In actual correction, it is not always 0 because fine adjustment is performed. For example, when Gr = 0 and Gb ≠ 0, red is (R−Y) ′ = (R−Y) + Gb2 · (B−Y) ... [9] (B−Y) ′ = (B−Y)… [ 10], and magenta is (R−Y) ′ = (R−Y) + Gb1 · (B−Y) ... [11] (B−Y) ′ = (B−Y) ... [12]. Therefore, in this case, the phase of red can be adjusted by changing Gb2, and the phase of magenta can be adjusted by changing Gb1. At this time, the red phase and the magenta phase are corrected in the direction parallel to the (RY) axis in FIG.

Therefore, the phase of red can be two-dimensionally corrected on the vector diagram by changing Gr2 and Gb2. In addition, the phase of red can be two-dimensionally corrected by changing Gr1 and Gb1.

Although red and magenta have been described above,
As shown in FIG. 3, by changing Gr2 and Gb2, the yellow phase is changed, by changing Gr3 and Gb3, the green phase is changed, and by changing Gr4 and Gb4, the blue and cyan phases are changed, respectively. It can be corrected two-dimensionally.
In the conventional color reproduction correction method, when Gb ≠ 0, even when the magenta (BY) component is small, blue is also affected when magenta is adjusted, but the first color Since the reproduction correction circuit enables correction in four quadrants independently,
It does not affect blue when making magenta adjustments.

As described above, in the first color reproduction correction circuit,
There are four hue conditions depending on the magnitudes of the (RY) signal and the (BY) signal, that is, the (RY) axis, which is two straight lines in which the hue of the image intersects with each other set on the color vector diagram, and ( By identifying which one of the first to fourth quadrants divided by the (B-Y) axis belongs to and switching the values of Gr ′ and Gb ′ according to the four hue conditions, the quadrants of the first to fourth quadrants are changed. Independent color reproduction correction can be performed for each hue.

(Second Color Reproduction Correction Circuit) The second color reproduction correction circuit inputs the (R-Y) signal input and the (B-Y) signal input to the above-mentioned first color reproduction correction circuit. A third comparison unit that compares the third reference value Th, a first control unit that controls the output of the first multiplication unit by the output of the third comparison unit, and a third comparison unit that outputs by the third comparison unit. And a second control unit for controlling the output of the second multiplication unit.

The second color reproduction correction circuit is basically the same correction as the first color reproduction correction circuit, that is, the equation [3],
The correction shown in [4] is performed. However, when the hue to be corrected exists at a distance less than the predetermined reference value from the (RY) axis or the (BY) axis shown in FIG. 8, the second color reproduction correction circuit Stop the correction.

FIG. 4 is a block diagram showing the configuration of the second color reproduction correction circuit. In this block diagram,
The second comparison units 31, 32, the gain selection signal generation unit 33, the first,
Second gain switching units 34, 35, first and second multiplication units 36, 3
7, the first and second adding units 38 and 39 are respectively the first and second comparing units 21 and 22, the gain selection signal generating unit 23, and the first and second gain switching units 24 and 25 of FIG. , The first and second multiplication units 2
6, 27 and the second adding units 28, 29 are configured in the same manner.
The third comparing section 40 compares the (RY) signal that is the first color difference signal and the (BY) signal that is the second color difference signal with the third reference value Th, and obtains the comparison result. According to the first control unit 41, the first
And controls the output of the multiplication unit 36 of the second control unit 42.
The output of the second multiplication unit 37 is controlled in accordance with. The control contents are as follows. If (R−Y) <Th… [13] or − (R−Y) <Th… [14] or (B−Y) <Th… [15] or − (B−Y) <Th… [16] For example, the output of the first multiplication unit 36 and the output of the second multiplication unit 37 are set to zero.

Therefore, if any one of these conditions is satisfied, the value added to the (RY) signal by the first adder 38 becomes 0, and the value added by the second adder 39 (B- The value added to the Y) signal is 0. In other words, no correction is performed, the (RY) signal remains as (RY) 'signal, and the (BY) signal remains as (B
-Y) 'signal. On the other hand, if none of these conditions is satisfied, the same correction as the first color reproduction correction circuit is performed.

Next, the operation of the second color reproduction correction circuit will be described below with reference to FIGS. 3 and 5 to 7, which are vector diagrams when a color bar chart is imaged. First, the correction operation when none of the above conditions [13] to [16] is satisfied is the same as that of the first color reproduction correction circuit. That is,
Since the correction is performed according to the equations [3] to [12] described above, the correction as shown in FIG. 3 is performed. On the contrary,
When any one of the conditions [13] to [16] is satisfied, as shown in FIG. 5, for example, the hue to be corrected is (R
If it exists in the area P0 on or near the −Y) axis, the correction is stopped because the condition [15] or [16] is satisfied.

The reason why the correction is stopped in the case shown in FIG. 5 is as follows. When corrected according to the equations [3] to [12], as shown in FIG. 6 (a), theoretically, among the hues existing in the region P0, the right side from the (RY) axis, that is, (B). −Y) ≧ 0 hue is phase adjusted by Gr1 and Gb1, and is on the left side of the (R−Y) axis, that is, (B−
For hues of Y) <0, the phase is adjusted by Gr2 and Gb2. However, in actual correction, vector cracking may occur as shown in FIG. 6 (b). Therefore, in the second color reproduction correction circuit, if at least one of [13] to [16] is satisfied as shown in FIG. 7A, in other words, the hue to be corrected is (RY). ) Axis or (B-Y) axis at a distance less than a predetermined reference value Th, in other words, when it exists in the boundary area of gain switching for color reproduction correction, color reproduction correction is stopped. . As a result, vector cracking can be prevented as shown in FIG. 7B, and more accurate color reproduction correction can be performed. The reference value for the (RY) signal input and the reference value for the (BY) signal input may be different values.

Thus, in the second color reproduction correction circuit,
When the constants Gr 'and Gb' that identify the four-hue condition and determine the gain are switched according to the (RY) signal and the size of (BY), and the identified hue exists in the boundary region of the four-hue condition. Since the color reproduction correction is stopped, it is possible to perform independent color reproduction correction for the hues of the first to fourth quadrants and prevent vector breakage.

(Third Color Reproduction Correction Circuit) The third color reproduction correction circuit compares the (R-Y) signal input with the (B-Y) signal input to the above-mentioned first color reproduction correction circuit. A third comparison unit for changing the conditions in the gain selection signal generation unit,
The number of coefficients of the second gain switching unit is increased.

The third color reproduction correction circuit uses the following equations [17] to
Perform the correction described in [18]. (R−Y) ′ = (R−Y) + Gb ′ · (B−Y)… [17] (B−Y) ′ ＝ (B−Y) ＋ Gr ′ · (R−Y)… [18]

Here, Gr 'and Gb' are constants for determining the gain and change as follows depending on the magnitudes of the (RY) signal and the (BY) signal. If (R−Y) ≧ Vrr and (B−Y) ≧ Vrb and (R−Y) <(B−Y), then G
r '= Gr1 and Gb' = Gb1 If (R−Y) ≧ Vrr and (B−Y) ≧ Vrb and (R−Y) ≧ (B−Y), then G
If r '= Gr2 and Gb' = Gb2 (R−Y) ≧ Vrr and (B−Y) <Vrb and (R−Y) ≧ − (B−Y)
If Gr '= Gr3 and Gb' = Gb3 (R−Y) ≧ Vrr and (B−Y) <Vrb and (R−Y) <− (B−Y)
Gr ′ = Gr4 and Gb ′ = Gb4 (R−Y) <Vrr and (B−Y) <Vrb and − (R−Y) <− (B−Y), then r ′ = Gr5 and Gb ′ = Gb5 ( If R−Y) <Vrr and (B−Y) <Vrb and − (R−Y) ≧ − (B−Y), then Gr ′ = Gr6 and Gb ′ = Gb6 (R−Y) <Vrr and (B− If Y) ≧ Vrb and − (R−Y) <(B−Y)
If Gr '= Gr7 and Gb' = Gb7 (R−Y) <Vrr and (B−Y) ≧ Vrb and − (R−Y) ≧ (B−Y)
Gr '= Gr8 and Gb' = Gb8

Here, Vrr is the first reference value and Vrb is the second reference value. In short, eight hue conditions are identified by the magnitudes of the (RY) signal and the (BY) signal, and the values of Gr 'and Gb' are switched according to the eight hue conditions.

FIG. 8 is a block diagram showing the configuration of the third color reproduction correction circuit. In this block diagram,
The second comparing units 51 and 52, the first and second multiplying units 56 and 57, and the first and second adding units 58 and 59 are respectively the first and second units in FIG.
Are configured in the same manner as the comparison units 21 and 22, the first and second multiplication units 26 and 27, and the first and second addition units 28 and 29. The third comparing section 60 compares the magnitudes of the (RY) signal and the (BY) signal. The gain selection signal generation unit 53 outputs the output of the first comparison unit 51 and the second comparison unit 51.
By the output of the comparing section 52 and the output of the third comparing section 60, eight kinds of gain selection signals under the above conditions are generated. First
The gain switching unit 54 switches the first to eighth gain constants Gr1 to Gr8 according to the output signal of the gain selection signal generation unit 53.
The second gain switching unit 55 switches the ninth to sixteenth gain constants Gb1 to Gb8 according to the output signal of the gain selection signal generation unit 53.

Next, FIG. 9 is a vector diagram showing the operation of the third color reproduction correction circuit when a color bar chart is imaged.
Will be described below. Here, for convenience, the first reference value Vrr will be described as 0, and the second reference value Vrb will also be described as 0.
In practice, each reference value uses an optimum value so that a good vector can be obtained.

For example, the second quadrant of FIG. 9 {(R−Y) ≧ 0 and
The red and yellow existing in (B−Y) <0} will be described.

Red is (RY)> 0, (BY) <0, (RY)>-
Since it is (BY), (RY) '= (RY) + Gb3 · (BY) (BY)' = (BY) + Gr3 · (RY) yellow is ( Since (R−Y)> 0, (B−Y) <0, and (R−Y) <− (B−Y), (R−Y) ′ = (R−Y) + Gb4 · (B−Y) ( B−Y) ′ = (B−Y) + Gr4 ・ (R−Y)

Therefore, the red phase can be adjusted by changing Gr3 and Gb3, and the yellow phase can be adjusted by changing Gr4 and Gb4. Similarly, Gr
2, change the phase of magenta by changing Gb2, Gr
6, the phase of green by changing Gb6, Gr7, Gb7
It is possible to independently change the cyan phase by changing, and the blue phase by changing Gr8 and Gb8.

Thus, in the third color reproduction correction circuit,
Depending on the size of the (RY) signal and the size of (BY), 8 hue conditions, that is, the hue of the image is (RY) in the color vector diagram.
Axis A, (B-Y) axis, and straight line A passing through the origin and orthogonal to each other
-Which of eight areas divided by -A 'and BB' belongs is identified, and the values of Gr 'and Gb' are switched according to the eight hue conditions. Therefore, each of these eight areas is independent. It is possible to perform color reproduction correction.

(Fourth Color Reproduction Correction Circuit) The fourth color reproduction correction circuit compares the (R-Y) signal and the (B-Y) signal with the third reference to the third color reproduction correction circuit. A fourth comparison unit for comparing the value, a first control unit for controlling the output of the first multiplication unit by the output of the fourth comparison unit, and a second control unit for the output of the fourth comparison unit.
And a second control unit for controlling the output of the multiplying unit. That is, it can be said to be a combination of the third color reproduction correction circuit and the second color reproduction correction circuit.

The fourth color reproduction correction circuit basically has the same correction as the third color reproduction correction circuit, that is, equations [17] and [1
Perform the correction shown in [8]. However, in the fourth color reproduction correction circuit, the hue to be corrected is the (R-Y) axis shown in FIG.
If the distance from any one of the (BY) axis, the straight line AA ', or the straight line BB' is less than the predetermined reference value, the correction is stopped.

FIG. 10 is a block diagram showing the structure of the fourth color reproduction correction circuit. In this block diagram, first, second and third comparing sections 61, 62 and 73, gain selection signal generating section 63, first and second gain switching sections 64 and 65, first and second
The multiplication units 66, 67, and the first and second addition units 68, 69 of the first, second, and third comparison units 5 of the color reproduction correction circuit of FIG.
1, 52, 60, gain selection signal generation unit 53, first and second gain switching units 54, 55, first and second multiplication units 56, 57, first,
It is configured similarly to the second adding units 58 and 59. The fourth comparison unit 70 compares the (RY) signal that is the first color difference signal and the (BY) signal that is the second color difference signal with the third reference value Th, and obtains the comparison result. Accordingly, the first control unit 71 controls the first multiplication unit.
The output of 66 is controlled, and the output of the second multiplication section 67 is controlled by the second control section 72. The control contents are as follows. (R−Y) <Th… [19] or − (R−Y) <Th… [20] or (B−Y) <Th… [21] or − (B−Y) <Th… [22] or If | (R−Y) | − | (B−Y) | <Th ... [23], the output of the first multiplication unit 66 and the output of the second multiplication unit 67 are set to zero.

Therefore, if any one of these conditions is satisfied, the value added to the (RY) signal by the first adder 68 is 0, and the value added by the second adder 69 (B-Y). The value added to the Y) signal is 0. In other words, no correction is performed, the (RY) signal remains as (RY) 'signal, and the (BY) signal remains as (B
-Y) 'signal. On the other hand, when none of these conditions is satisfied, the same correction as the third color reproduction correction circuit is performed.

Next, the operation of the fourth color reproduction correction circuit will be described below with reference to FIGS. 9 and 11 to 13, which are vector diagrams when a color bar chart is imaged. First, the correction operation when none of the conditions [19] to [23] described above is satisfied is the same as that of the third color reproduction correction circuit. That is,
The correction is performed as shown in FIG. On the contrary,
When any one of the conditions [19] to [23] is satisfied, for example, as shown in FIG. 11, the hue to be corrected exists in the area P1 on the straight line AA ′ or in the vicinity thereof. If so, the condition [23] is satisfied, and the correction is stopped.

The reason for stopping the correction in the case shown in FIG. 11 is as follows. When the same correction as the third color reproduction correction circuit is performed, as shown in FIG. 12 (a), theoretically, from the straight line AA ′ of the hues existing in the area P1, Circumferential side, that is, (R-Y) <(B
-Y) hue is adjusted by Gr1 and Gb1 and the counterclockwise direction from the straight line A-A ', that is, (R-Y) ≧
For the (BY) hue, phase adjustment is performed by Gr2 and Gb2. However, in actual correction, vector cracking may occur as shown in FIG. Therefore, in the fourth color reproduction correction circuit, if even one of [19] to [23] is satisfied as shown in FIG. 13A, in other words, the hue to be corrected is (RY). ) Axis or (BY) axis or straight line A-A 'or straight line BB' at a predetermined distance less than the reference value Th, in other words, hue discrimination for color reproduction correction. If it exists in the boundary area of, the color reproduction correction is stopped. As a result, as shown in FIG. 13B, vector cracking can be prevented and more accurate color reproduction correction can be performed.

As described above, in the fourth color reproduction correction circuit,
When the constants Gr 'and Gb' that determine the gain by identifying the 8 hue conditions by the (RY) signal and the size of (BY) are switched, and the identified hue exists in the boundary area of the 8 hue conditions. Since the color reproduction correction is stopped in the area, the color vector diagram is divided by the (RY) axis, the (BY) axis, and the straight lines AA ′ and BB ′ that pass through the origin and are orthogonal to each other. Independent color reproduction correction can be performed for the two areas, and vector cracking can be prevented.

(Pedestal Processing Circuit) In the pedestal processing circuit of the embodiment of the present invention, the four hue conditions are identified by the magnitudes of the (RY) signal and the (BY) signal, and the four hue conditions are determined according to the four hue conditions. Switching the petestal value. This pedestal processing circuit performs pedestal processing represented by the following equation [24]. Y '= Y + Pd ... [24]

Here, Pd is a pedestal value, which changes as follows depending on the magnitudes of the (RY) signal and the (BY) signal. If (R−Y) ≧ Vrr and (B−Y) ≧ Vrb, then Pd = Pd1 (R−Y) ≧ Vrr and (B−Y) <Vrb, then Pd = Pd2 (R−Y) <Vrr and (B−Y ) <Vrb, Pd = Pd3 (R−Y) <Vrr and (B−Y) ≧ Vrb, Pd = Pd4

Here, Vrr is the first reference value and Vrb is the second reference value. For the sake of convenience, the first reference value and the second reference value have the same sign as the sign used in the color reproduction correction circuit, but they do not necessarily mean the same value (the same applies to the following embodiments. ).

FIG. 14 is a block diagram showing the structure of the pedestal processing circuit. In this pedestal processing circuit, the first comparison unit 201 compares the (RY) signal that is the first color difference signal with the first reference value Vrr, and the second comparison unit 202 outputs the second reference value Vrr.
The (BY) signal, which is the color difference signal of, is compared with the second reference value Vrb. These comparison units 201 and 202 correspond to the hue determination unit 5 in FIG. The pedestal value switching unit 204 inputs the first to fourth pedestal values Pd1 to Pd4, selects one of them, and outputs it. The pedestal value selection signal generation unit 203 generates four types of pedestal value selection signals according to the above conditions by the output of the first comparison unit 201 and the output of the second comparison unit 202 and supplies them to the pedestal value switching unit 204. . Pedestal value switching unit 204
The pedestal value selection signal generator 203 corresponds to the coefficient controller 6 of FIG. The adding unit 205 adds any one of the pedestal values selected by the pedestal value switching unit 204 to the Y signal and outputs it as a Y ′ signal.

As described above, in the pedestal processing circuit according to the embodiment of the present invention, the four hue conditions are identified by the magnitudes of the (RY) signal and the (BY) signal, and the petestal value is determined according to the four hue conditions. Since it is switched, an appropriate pedestal value can be independently set for each quadrant for the hues of the first to fourth quadrants.

(Level Compression / Expansion Processing Circuit) In the level compression / expansion processing circuit according to the embodiment of the present invention, the four hue conditions are identified by the sizes of the (RY) signal and the (BY) signal. The Y signal gain is switched according to the four hue conditions. This level compression / decompression processing circuit performs level compression / decompression processing represented by the following equation [25]. Y '= Y × Gy ... [25]

Here, Gy is a coefficient for setting the gain, and (R
It changes as follows depending on the magnitude of −Y) signal and (B−Y) signal. If (R−Y) ≧ Vrr and (B−Y) ≧ Vrb then Gy = Gy1 (R−Y) ≧ Vrr and (B−Y) <Vrb if Gy = Gy2 (R−Y) <Vrr and (B−Y ) <Vrb, Gy = Gy3 (R−Y) <Vrr and (B−Y) ≧ Vrb, Gy = Gy4 where Vrr is the first reference value and Vrb is the second reference value.

FIG. 15 is a block diagram showing the structure of the level compression / expansion processing circuit. In this level compression / expansion processing circuit, the first comparison unit 211 compares the (RY) signal, which is the first color difference signal, with the first reference value Vrr, and the second comparison unit 212 outputs the second reference signal Vrr. The (BY) signal, which is a color difference signal, is compared with the second reference value Vrb. These comparison units 211 and 212 correspond to the hue determination unit 5 in FIG. The gain switching unit 214 is the first to fourth
The coefficients Gy1 to Gy4 of are input and one of them is selected and output. The gain selection signal generation unit 213 generates a signal for selecting four coefficient values according to the above conditions from the output of the first comparison unit 211 and the output of the second comparison unit 212, and the gain switching unit
Supply to 214. The gain switching unit 214 and the gain selection signal generation unit 213 correspond to the coefficient control unit 6 in FIG. The multiplying unit 215 outputs Y to one of the gains selected by the gain switching unit 201.
The signal is multiplied and output as a Y ′ signal.

As described above, in the level compression / expansion processing circuit according to the embodiment of the present invention, the four hue conditions are identified by the magnitudes of the (RY) signal and the (BY) signal, and the four hue conditions are determined. Since the gain of the Y signal is switched according to the above, it is possible to perform appropriate level compression / expansion processing independently for each hue in the first to fourth quadrants.

(Contour Correction Circuit) In the contour correction circuit according to the embodiment of the present invention, the four hue conditions are identified by the magnitudes of the (RY) signal and the (BY) signal, and the four hue conditions are determined according to the four hue conditions. The amount of detail for contour enhancement is switched. This contour correction circuit performs the contour enhancement processing represented by the following equation [26]. Y '= Y + YxCo ... [26]

Here, Go is a coefficient for switching the detail amount of contour enhancement, and changes as follows depending on the magnitudes of the (RY) signal and the (BY) signal. If (R−Y) ≧ Vrr and (B−Y) ≧ Vrb, Co = Co1 (R−Y) ≧ Vrr and (B−Y) <Vrb, Co = Co2 (R−Y) <Vrr and (B−Y ) <Vrb, Co = Co3 (RY) <Vrr and (BY) ≧ Vrb, Co = Co4 where Vrr is the first reference value and Vrb is the second reference value.

FIG. 16 is a block diagram showing the structure of the contour correction circuit. In this contour correction circuit, the first comparison section 221 compares the (RY) signal, which is the first color difference signal, with the first reference value Vrr, and the second comparison section 222 outputs the second color difference signal. A certain (BY) signal is compared with the second reference value Vrb. These comparison units 221 and 222 correspond to the hue determination unit 5 in FIG. The detail amount switching unit 224 inputs the first to fourth coefficients Co1 to Co4, selects one of them, and outputs it. The detail amount selection signal generation unit 223 generates a signal for selecting four coefficient values according to the above conditions by the output of the first comparison unit 221 and the output of the second comparison unit 222, and outputs the signal to the detail amount switching unit 224. Supply. The detail amount switching unit 224 and the detail amount selection signal generation unit 223 correspond to the coefficient control unit 6 in FIG. The contour correction unit 226 generates a contour correction signal in which the detail amount of the Y signal is controlled according to the coefficient value selected by the detail amount switching unit 224, and outputs the contour correction signal to the addition unit 225. The adder 225 adds the contour correction signal to the Y signal and outputs it as a Y ′ signal.

As described above, in the contour correction circuit according to the embodiment of the present invention, the four hue conditions are identified by the magnitudes of the (RY) signal and the (BY) signal, and the contour correction is performed according to the four hue conditions. Since the amount of detail of the signal is switched, it is possible to perform appropriate contour correction processing independently for each hue in the first to fourth quadrants.

[0094]

As described above, the video signal processing apparatus of the present invention
Is the number that intersects each other set on the color vector diagram.
The hue discrimination means for discriminating the hue from the video signal in units of areas divided by the straight line, the color reproduction correction means for performing the color reproduction correction on the video signal, and the color reproduction correction according to the discrimination output of the hue discrimination means. and a color reproduction correction coefficient control means for changing the color reproduction correction coefficient means, video signal processing apparatus der performing color reproduction correction corresponding to the color on the video signal
The hue discriminator discriminated by the hue discriminator.
The distance from the straight line of the number is determined, and the
Since the color reproduction correction of the notational color reproduction correction means is stopped, the optimum color reproduction correction can be applied to the video signal according to the hue, and each color can be reproduced more beautifully.

[0095]

[0096]

[0097]

[0098]

[0099]

[Brief description of drawings]

FIG. 1 is a block diagram of an image pickup apparatus according to an embodiment of the present invention,

FIG. 2 is a block diagram of a first color reproduction correction circuit according to an embodiment of the present invention,

FIG. 3 is a color vector diagram of the first color reproduction correction circuit and the second color reproduction correction circuit according to the embodiment of the present invention;

FIG. 4 is a block diagram of a second color reproduction correction circuit according to the embodiment of the present invention,

FIG. 5 is a color vector diagram in the case where a hue exists in a gain switching boundary area in the second color reproduction correction circuit;

6A is an explanatory diagram showing phase adjustment in a boundary area of gain switching in the first color reproduction correction circuit, and FIG. 6B is an explanatory diagram showing vector breakage in the first color reproduction correction circuit;

7A is an explanatory view showing phase adjustment in a boundary area of gain switching in the second color reproduction correction circuit, and FIG. 7B is an explanatory view showing vector breakage prevention in the second color reproduction correction circuit;

FIG. 8 is a block diagram of a third color reproduction correction circuit according to an embodiment of the present invention,

FIG. 9 is a color vector diagram of a third color reproduction correction circuit and a fourth color reproduction correction circuit according to the embodiment of the present invention;

FIG. 10 is a block diagram of a fourth color reproduction correction circuit according to the embodiment of the present invention,

FIG. 11 is a color vector diagram in the case where a hue exists in a boundary area for gain switching in the fourth color reproduction correction circuit;

FIG. 12 (a) is an explanatory view showing phase adjustment in a boundary region of gain switching in the third color reproduction correction circuit, and (b).
Explanatory diagram showing vector cracks in the third color reproduction correction circuit,

13A is an explanatory diagram showing phase adjustment in a boundary region of gain switching in the fourth color reproduction correction circuit, FIG.
Explanatory diagram of vector crack prevention in the fourth color reproduction correction circuit,

FIG. 14 is a block diagram showing a configuration of a pedestal processing circuit according to an embodiment of the present invention,

FIG. 15 is a block diagram showing a configuration of a level compression / expansion processing circuit according to the embodiment of the present invention;

FIG. 16 is a block diagram showing a configuration of a contour correction circuit according to an embodiment of the present invention,

FIG. 17 is a block diagram of an image pickup apparatus for explaining a conventional example;

FIG. 18 is a block diagram of a color reproduction correction circuit in a conventional example,

FIG. 19 is a color vector diagram when a color bar chart in a conventional example is imaged.

[Explanation of symbols]

1 Image Sensor 3 Luminance Signal Processor 4 Color Signal Processor 5 Hue Discriminator 6 Coefficient Controller 7 Coefficient Generator 10 Recording Medium 11 Transmitter 21, 22, 31, 32, 40, 51, 52, 60, 61, 62 , 70, 73 Comparison section 23, 33, 53, 63 Gain selection signal generation section 24, 25, 34, 35, 54, 55, 64, 65 Gain switching section 26, 27, 36, 37, 56, 57, 66, 67 Multiplier 28, 29, 38, 39, 58, 59, 68, 69 Adder 41, 42, 71, 72 Controller 203 Pedestal value selection signal generator 204 Pedestal value switching unit 213 Gain selection signal generator 214 Gain switching 223 Detail amount selection signal generation unit 224 Detail amount switching unit 226 Contour correction unit

Claims (4)

(57) [Claims] 1. Interchanges set on a color vector diagram
Hue discriminating means for discriminating the hue from the video signal in units of regions divided by a plurality of different straight lines, color reproduction correcting means for performing color reproduction correction on the video signal, and the color discriminating means according to the discrimination output of the hue discriminating means. A video signal processing device , comprising: a color reproduction correction coefficient control means for changing a color reproduction correction coefficient of a color reproduction correction means, for performing color reproduction correction according to the hue on the video signal, wherein the hue determination means determines the color reproduction correction coefficient. Color
Judgment result of the distance from the above multiple straight lines of the phase
A video signal processing apparatus according to claim and this <br/> stopping the color reproduction correction of the color reproduction correction means in accordance with the. 2. A hue discrimination means for discriminating a hue from a video signal, a color reproduction correction means for performing color reproduction correction on the video signal, and the color reproduction complement according to the discrimination output of the hue discrimination means.
Bei example a color reproduction correction coefficient control means for changing the color reproduction correction coefficient positive means, a color reproduction correction corresponding to the hue A video signal processing apparatus for performing the above video signal, the hue determination
Means compare the first color difference signal input with a first reference value
A first comparing section, a second color difference signal input and a second reference value
Outputs of a second comparing section for comparing
And the output of the second comparison unit, a plurality of gain constants
A gain selection signal generator for generating a signal to be switched,
The output of the gain selection signal generator allows multiple gain constants.
Of the first and second gains that switch between and output
Switching unit, the first color difference signal input and the first gain switch
A first multiplication unit for multiplying the output of the conversion unit, and the second color
Multiply the difference signal input by the output of the second gain switching section
A second multiplication unit, the first color difference signal input, and the second
Third comparison for comparing the color difference signal input with the third reference value
Section and the output of the third comparison section, the first multiplication
A first control unit for controlling the output of the unit and the third comparison unit
Output of the second multiplication unit for controlling the output of the second multiplication unit.
Control section, the first color difference signal input and the second control
First addition to obtain the first corrected output
Section, the second color difference signal input and the output of the first control section.
And a second addition unit that obtains a second corrected output by adding the force and
A video signal processing device characterized by having . 3. A hue discrimination means for discriminating a hue from a video signal, a color reproduction correction means for performing a color reproduction correction on the video signal, and the color reproduction complement according to the discrimination output of the hue discrimination means.
Bei example a color reproduction correction coefficient control means for changing the color reproduction correction coefficient positive means, a color reproduction correction corresponding to the hue A video signal processing apparatus for performing the above video signal, the hue determination
Means compare the first color difference signal input with a first reference value
A first comparing section, a second color difference signal input and a second reference value
And a second comparing section for comparing the first color difference signal input
And a third comparing section for comparing the second color difference signal input
And the outputs of the first, second, and third comparison units described above
Gain selection signal that generates a signal that switches the gain constant of
The output signal of the generator and the gain selection signal generator is
Output by switching any of the gain constants.
1, a second gain switching section, and the first color difference signal input
First multiplication for multiplying with the output of the first gain switching unit
Section, the second color difference signal input and the second gain switching
A second multiplication unit that multiplies the output of the unit and the first color difference
The signal input and the output of the upper second multiplication unit are added, and the first complement
A first adder for obtaining a positive output and the second color difference signal input
And the output of the first multiplication unit are added to obtain a second corrected output.
And a second adding section for obtaining the video signal. 4. A hue discriminating means for discriminating a hue from a video signal, a color reproduction correcting means for performing color reproduction correction on the video signal, and the color reproduction complement according to the discrimination output of the hue discriminating means.
Bei example a color reproduction correction coefficient control means for changing the color reproduction correction coefficient positive means, a color reproduction correction corresponding to the hue A video signal processing apparatus for performing the above video signal, the hue determination
Means compare the first color difference signal input with a first reference value
The first comparing section and the second color difference signal input to the second reference value.
A second comparing section for comparing with the first color difference signal input and the second
A third comparing section for comparing the color difference signal input of
A plurality of gain constants are output by the outputs of the first, second, and third comparison units.
A gain selection signal generator that generates a signal for switching
A plurality of gain constants are output by the output of the gain selection signal generator.
First and second gains for switching and outputting any of the numbers
A switching unit, the first color difference signal input and the first gain
A first multiplication unit for multiplying the output of the switching unit and the second multiplication unit;
Multiply the color difference signal input by the output of the second gain switching unit
A second multiplying unit, the first color difference signal input, and the first color difference signal input
The fourth comparing the difference between the second color difference signal input and the third reference value
Of the first comparison unit and the output of the fourth comparison unit.
A first control unit for controlling the output of the multiplication unit of
The output of the second multiplication unit is controlled by the output of the comparison unit.
A second controller, the first color difference signal input and the second
Output of the control unit of the first addition to obtain a first corrected output
Adder, the second color difference signal input, and the first control
Second addition to obtain the second corrected output
A video signal processing apparatus characterized in that with the part.