JPH0787512A - Color signal outline compensation circuit - Google Patents

Abstract

PURPOSE:To improve the picture visibility by using a high-band component, which is used as a compensation signal, divisionally in an attenuating circuit and a multiplying circuit in accordance with the polarity of the high-band component so that the polarity of a color signal is not changed and correcting the outline without the degradation in picture quality like the change of hue occurring in the outline. CONSTITUTION:First, a polarity separation circuit 3 is used to separate the high-band component into a positive polarity signal and a negative polarity signal. The positive polarity component of the high-band component is multiplied by a color signal in a multiplying circuit 6 to perform outline compensation. The polarity of the outputted color signal coincides with the polarity of the inputted color signal because the high- band component by which the color signal is multiplied is the signal having only a positive value, and the negative polarity component of the high-band component is used to control the extent of attenuation of an attenuating circuit 5. Consequently, the color signal is more attenuated for the longer negative component amplitude and is outputted. At this time, the amplitude is only approximated to zero however large the negative component of the luminance signal is, and the polarity is not inverted. Thus, the color signal is effectively attenuated to obtain vivid meshes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color signal contour compensating circuit used in an apparatus for handling image signals.

[0002]

2. Description of the Related Art Generally, a color signal band in an image signal is narrower than a luminance signal. For example, in the NTSC system, the band of the luminance signal is about 4.2 MHz, whereas the I signal of the color difference signal is defined as 1.5 MHz and the Q signal is defined as 0.5 MHz. This standard is determined based on human visual characteristics, but is not always sufficient, and there are some problems in image quality due to narrow band color difference signals. For example, in the case of a vertical stripe pattern, the reproducibility of color is deteriorated, the color edge part is broken (color unnatural hue discontinuity occurs), and the color edge part color sag (color protrusion) occurs. This decrease in color reproducibility cannot be improved unless the standards for I and Q signals are changed to increase the bandwidth. This problem was left open to the user, who felt unnatural for the recipient who was not notified of the original image. However, this problem is becoming more serious as the performance of television receivers has recently been improved. Therefore, attention has been paid to the improvement of color edges, and several color signal contour compensation circuits have been proposed so far. However, in the conventional color signal contour compensating circuit, the hue is erroneously changed due to the ringing of the waveform generated for contour compensation, the difference in the frequency band of the I signal and the Q signal, the error in the compensation amount, etc. There was a problem of significant deterioration.

An example of solving this problem is the "color signal contour compensation circuit" described in Japanese Patent Application No. 3-113347 by Numata and Fujishima. In this contour compensation circuit, focusing on the fact that the color signal is expressed as a vector, the carrier color signal modulated by the color subcarrier is separated into a hue signal indicating the hue and an envelope detection signal indicating the saturation of the color. However, only the latter signal is compensated for high frequency components. The envelope detection signal in which the high frequency components have been compensated is re-modulated by the previously separated hue signal and output as a carrier color signal. FIG. 9 shows the configuration of the color signal contour compensation circuit described in this publication. I
Since the compensation circuits for the signal and the Q signal are the same, the I signal will be taken as an example and described in more detail below. In this figure, the I signal taken into the input terminal 71 is sent to the limiter 73 and the envelope detection circuit 75. The envelope detection circuit 75 performs envelope detection of the I signal and outputs a signal relating to the degree of saturation to the addition circuit 76. On the other hand, the luminance signal Y taken into the input terminal 72 is a high-pass filter (hereinafter referred to as HPF).
It is passed through 77 and its high frequency component is sent to the adding circuit 76. In the adder circuit 76, the output of the envelope detection circuit 75 and the output of the HPF 77 are used as two inputs to perform addition.
The addition result is output to the rectifier circuit 78. Rectifier circuit 78
Is only the positive component in the output of the adder circuit 76.
Output to 4. In this way, the output of the envelope detection circuit 75 becomes a waveform having a steep rise and a fall due to the high frequency component of the luminance signal output from the HPF 77. However, the output of the adder circuit 76 is a signal having a negative component due to the high frequency component added by the HPF 77. The output of the envelope detection circuit 75 is a signal indicating the color intensity, and there cannot be a negative value with respect to the color intensity. When the negative component is output as it is to form an image, it becomes a component showing a complementary color. Therefore, in this example, the rectifying circuit 78 removes the negative component to prevent this adverse effect. In the limiter 73, a signal of a constant amplitude indicating the hue of the I signal is multiplied by the multiplication circuit 74
Output to. As a result, in the multiplication circuit 74, the limiter 7
The output of the rectifier circuit 78 is modulated by the signal from the signal No. 3 and the contour-compensated I signal is output. In this color signal contour compensating circuit, by compensating only for the degree of color saturation, the adverse effect due to an unnatural hue change caused by the compensation is prevented.

[0004]

However, the conventional color signal contour compensating circuit shown in FIG. 9 has a problem that the circuit configuration is very complicated and is difficult to realize.

The present invention has been proposed in order to solve the problems of the prior art as described above, and can be configured using only an easily realizable circuit, and furthermore, an unnatural hue change due to compensation. It is an object of the present invention to provide a color signal contour compensating circuit which can improve the vividness of colors without any adverse effects.

[0006]

In order to achieve this object, a color signal contour compensating circuit according to the present invention has a high frequency band which receives at least one of a luminance signal and a color signal and outputs this high frequency component. A pass filter and the output of this high-pass filter are input, a polarity separation circuit that separates and outputs the positive component and the negative component, and the negative component output of this polarity separation circuit is one input, and the color signal of the other An attenuation circuit that attenuates and outputs a color signal in proportion to the amplitude of the negative component output as an input,
The positive component output of the polarity separation circuit is used as one input, and the output of this attenuation circuit is used as the other input to perform multiplication and output a contour-compensated color signal. It is composed.

Further, the color signal contour compensating circuit according to the present invention receives a signal of at least one of a luminance signal and a chrominance signal as an input and outputs a high pass component, and an output of the high pass filter. A polarity separation circuit that separates and outputs a positive component and a negative component, a multiplication circuit that performs multiplication by using the positive component output of this polarity separation circuit as one input and a color signal as the other input, and the polarity described above. The negative component output of the separation circuit is used as one input, the output of this multiplication circuit is used as the other input, the color signal is attenuated in proportion to the amplitude of the negative component output, and an attenuator circuit that outputs a contour-compensated color signal is used. It is provided as a configuration.

Further, the color signal contour compensating circuit according to the present invention receives a luminance signal or at least one of the color signals as an input, and outputs a high-pass component, and a horizontal blanking of the luminance signal. A horizontal blanking period detection circuit that detects part or all of the period and outputs a detection signal, and the output of this horizontal blanking period detection circuit as one input and the color signal as the other input. A voltage comparison circuit that compares the voltage of the color signals with respect to the color signal voltage in the line erasing period and outputs positive and negative; and an output of the high-pass filter as one input and a color signal as the other input to perform addition No. 1 addition circuit, a multiplication circuit for performing multiplication by using the output of the first addition circuit as one input and the output of the voltage comparison circuit as the other input, and a negative component with the output of this multiplication circuit as input. An output rectifier circuit, a subtractor circuit that subtracts the output of the rectifier circuit from the output of the high-pass filter, and an output, and the output of the subtractor circuit is used as one input, and the color signal is added as the other input to perform addition. A second adding circuit that outputs a color signal whose contour has been compensated is provided.

Further, the color signal contour compensating circuit according to the present invention receives the luminance signal or at least one of the color signals as an input and outputs a high-pass component, and a horizontal blanking of the luminance signal. A horizontal blanking period detection circuit that detects part or all of the period and outputs a detection signal, and the output of this horizontal blanking period detection circuit as one input and the color signal as the other input. A first voltage comparison circuit that compares the voltage of the color signal with respect to the color signal voltage in the line erase period as a reference and outputs positive and negative, and the output of the high-pass filter is one input, and the color signal is added as the other input. And a first multiplication circuit for performing multiplication by using the output of the first addition circuit as one input and the output of the first voltage comparison circuit as the other input, and the first addition circuit. Multiplication circuit A rectifier circuit that receives the output as an input and outputs a negative component, a subtractor circuit that subtracts the output of the rectifier circuit from the output of the high-pass filter, and outputs a color signal as one input, and detects the horizontal blanking period. A second voltage comparison circuit which detects the presence or absence of a color signal amplitude of a certain value or more with reference to the color signal voltage in the horizontal blanking period and outputs the other voltage as the other input, and the second voltage comparison circuit. A second multiplication circuit for performing multiplication using the output of the circuit as one input and the output of the subtraction circuit as the other input;
The second addition circuit that outputs the contour-compensated color signal by adding the output of the multiplication circuit of (1) as one input and the color signal as the other input, and outputting the contour-compensated color signal.

[0010]

According to the above-mentioned structure corresponding to claim 1 and claim 2, the high frequency component used as the compensation signal is multiplied by the attenuation circuit by the polarity of the high frequency component so as not to change the polarity of the color signal. Used by dividing into circuits. Therefore, the color signal can be edge-compensated by the luminance signal or the high frequency component of the color signal without deterioration of the image quality such as a hue change occurring in the edge portion, and the sharpness of the image quality can be improved.

Further, according to the configurations according to claims 3 and 4, the deterioration of the hue caused by the compensation can be removed by the subtraction circuit. Therefore, the color signal can be contour-compensated by the luminance signal or the high frequency component of the color signal without deterioration of the image quality, and the sharpness of the image quality can be improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of a color signal contour compensating circuit according to the present invention will be described in detail below with reference to the drawings. An embodiment of this color signal contour compensation circuit is shown in the block diagram of FIG. In this figure, the luminance signal Y input to the input terminal 1
Is passed through the HPF 2 and its high frequency component is the polarity separation circuit 3
Sent to. The polarity separation circuit 3 outputs a positive component from the high frequency component to the multiplication circuit 6 and a negative component to the attenuation circuit 5. The attenuator circuit 5 uses the color signal C taken into the input terminal 4 as one input and the negative polarity output output from the polarity separation circuit 3 as the other input to attenuate the color signal proportional to the amplitude of the negative polarity output. Then, the color signal is output to the multiplication circuit 6. The multiplication circuit 6 performs multiplication by using this signal as one input and the positive input output from the polarity separation circuit 3 as the other input, and outputs a contour-compensated color signal C. The most harmful effect when compensating for color signals is
It is the inversion of hue that occurs after contour compensation. For example, if there is a large change in the luminance signal on a screen with a low degree of saturation, in other words a screen with a small color signal amplitude, the high frequency component amplitude will greatly exceed the color signal amplitude. At this time, if addition or multiplication is performed using the high frequency component of the luminance signal, not only the amplitude of the original color signal but also the sign thereof may be changed. The purpose of the color signal contour compensation circuit is to give a sharp change in the amplitude to the color contour portion, and it is necessary to avoid a change that changes even the sign. Therefore, in the present invention, attention is paid to the polarity of the high frequency component used for compensation, and the compensation method is switched depending on the polarity. First, the polarity separating circuit 3 separates a high frequency component into a positive polarity signal and a negative polarity signal. The positive component of the high frequency component is multiplied by the color signal by the multiplication circuit 6 to be contour-compensated. Since the high frequency component multiplied by the color signal is a signal having only a positive value, the polarity of the output color signal matches the polarity of the input color signal. The negative component of the high frequency component is used to control the attenuation amount of the attenuation circuit 5. Therefore, the color signal is attenuated more as the negative component amplitude increases, and the attenuation circuit 5
Will be output. In this case, no matter how large a negative component the luminance signal has, the amplitude of the chrominance signal only approaches zero, and the polarity never reverses beyond zero. Therefore, even if the shade is the same as that seen in the stitches of the sweater, there is a large change in the luminance in the areas where shade is likely to occur, so the color signal can also be effectively attenuated, and clear stitches can be displayed. .

Next, another embodiment shown in FIG. 2 will be described. In this figure, the luminance signal Y captured in the input terminal 11
Is passed through the HPF 12, and its high frequency component is sent to the polarity separation circuit 13. The polarity separation circuit 13 outputs a positive polarity component from the high frequency component to the multiplication circuit 15 and a negative polarity component to the attenuation circuit 16. In the multiplication circuit 15, the input of the positive polarity component output from the polarity separation circuit 13 is used as one input, and the color signal C taken into the input terminal 14 is used as the other input to perform multiplication and output to the attenuation circuit 16. In the attenuator circuit 16, this multiplication signal is used as one input and the negative polarity output output from the polarity separation circuit 13 is used as the other input to attenuate the output of the multiplier circuit 15 in proportion to the amplitude of the negative polarity output, and perform contour compensation. The color signal C thus generated is output.

Next, another embodiment shown in FIG. 3 will be described. In this figure, the luminance signal Y input to the input terminal 21
Is passed through the HPF 22, and its high frequency component is sent to the half-wave rectification circuit 23 and the subtraction circuit 24. The half-wave rectification circuit 23 receives the signal from the HPF 22 as an input and outputs only the positive component to the subtraction circuit 24 and the multiplication circuit 27. The subtraction circuit 24 has an H
Subtract the output of the half-wave rectifier circuit 23 from the output of PF22,
The subtraction result is output to the attenuation amount control input terminals of the electronic volume controls 26 and 29. The electronic volume 26 has an input terminal 2
The color signal I input to 5 is used as a controlled input, and the subtraction circuit 2
The output of 4 is used as a control input, the color signal is attenuated in proportion to the amplitude output from the subtraction circuit 24, and the output signal is output to the multiplication circuit 27. The multiplication circuit 27 uses this signal as one input and the output of the half-wave rectification circuit 23 as the other input to perform multiplication and output a contour-compensated color signal. The electronic volume 29 uses the color signal Q input to the input terminal 28 as a controlled input and the output of the subtraction circuit 24 as a control input to attenuate the color signal in proportion to the amplitude output from the subtraction circuit 24. Multiply circuit 3 for output signal
Output to 0. The multiplication circuit 30 uses this signal as one input and the output of the half-wave rectification circuit 23 as the other input to perform multiplication and output a contour-compensated color signal Q.

Next, the operation of the color signal contour compensation circuit will be described in more detail with reference to the waveform diagram of FIG. In addition,
Since the color signal I and the color signal Q have the same processing steps, the color signal I will be described. Now, it is assumed that the waveform S1 of the color signal I shown in a in the figure is input to the input terminal 25, and the luminance signal waveform S2 shown in b in the figure is input to the input terminal 21.
The HPF 22 outputs the waveform S3, which is the high frequency component of the luminance signal, shown in c in the figure to the half-wave rectification circuit 23 and the subtraction circuit 24.
The half-wave rectifier circuit 23 outputs only the positive component waveform S4 shown by d in the figure among the high frequency component waveforms that have passed through the HPF 22. The subtraction circuit 24 performs subtraction using the input / output signals of the half-wave rectification circuit 23 as two inputs, and outputs a waveform S5 of the subtraction result shown in e in the figure. The electronic volume 26 receives the waveform S5 as a control input and gives an attenuation amount proportional to this amplitude to the color signal waveform S1, and outputs a waveform S6 shown by f in the figure to the multiplication circuit 27. Here, the waveform S6 is output with the dotted line portion removed by the electronic volume control 26. Therefore, on a screen where the color does not change and only the brightness changes, for example, on a screen where forest trees are exposed to the sun and the shade and the sun are finely intricate, the waveform distortion due to insufficient band of color signals may occur. Can be effectively compensated. In such a screen, since the high frequency component is included only in the luminance signal, the electronic volume 26 imparts a waveform attenuation to the color signal by the high frequency component, and the reproducibility of the shaded portion can be improved. The waveform S6 output from the electronic volume 26 is multiplied by the waveform S4 by the multiplication circuit 27, the rising edge of the waveform S6 is further compensated, and output as a waveform S7 indicated by g in the figure. In general images, there is a strong correlation between the color change and the brightness change. For example, in a scene of an apple placed on a table, the brightness changes as the color changes at the outline of the table and the apple. By using the high-frequency component of the luminance signal as in the above-described example, it is possible to effectively suppress color bleeding that occurs with a change in luminance especially in such a scene. Further, since the I signal and the Q signal are simultaneously compensated by using the luminance signal high-frequency component, there is almost no color change in the stitches of the sweater and the scene where the leaves of the lawn are lined up, and it is large even in the portion where only the luminance is changed. Have an effect. Such a part is a part where the degree of color saturation should be originally reduced. However, in reality, due to the lack of the band of the I signal and the Q signal, the waveform that should have a sharp rise and fall is blunted. Therefore, by compensating the I signal and the Q signal in accordance with the change of the luminance signal high frequency component in this portion, it is possible to perform color contour compensation and obtain a clear image.

The case where the I signal is compensated using the luminance signal has been described above as an example, but the I signal or the Q signal, or both the I and Q signals and the luminance signal can be used as the signal used for the compensation. . Further, the circuit of FIG. 3 uses the half-wave rectification circuit 23 and the subtraction circuit 24 as the polarity separating means. However, as shown in FIG. 5, the half-wave rectification circuit 42 applies a negative component to the signal input to the input terminal 41. Can be output and the positive component can be output by subtraction by the subtraction circuit 43. Further, as the polarity separating means, as shown in FIG. 6, a signal input to the input terminal 44 may be input to both the half-wave rectifier circuits 45 and 46 to output a positive component and a negative component, respectively.

Next, a color signal contour compensating circuit of another embodiment shown in FIG. 7 will be described. In this figure, the input terminal 51
The I signal taken in is input to the adder circuits 55 and 62 and a voltage comparison circuit (hereinafter referred to as a comparator) 56.
In addition, the luminance signal taken into the input terminal 52 is the HPF5
4 and the horizontal blanking period detection circuit 53. The horizontal blanking period detection circuit 53 detects the horizontal blanking period of the luminance signal and outputs the detection signal to the comparator 5.
Output to 6, 60. The comparator 56 compares the positive and negative of the I signal with the I signal voltage in the horizontal blanking period as a reference for comparison, and outputs a comparison output to the multiplication circuit 57. Adder circuit 5
5 receives the I signal as one input and the luminance signal high frequency component output from the HPF 54 as the other input, performs addition, and outputs the addition result to the multiplication circuit 57. The multiplication circuit 57 uses the addition signal as one input and the output of the comparator 56 as the other input to perform multiplication, and outputs the multiplication result to the rectification circuit 58. The rectification circuit 58 rectifies the multiplication signal and outputs the negative component thereof to the subtraction circuit 59. In the subtraction circuit 59, the output of the rectification circuit 58 is used as one input, and the HPF 54
Is used as the other input, and the output of the rectifier circuit 58 is subtracted from the output of the HPF 54 and output to the multiplication circuit 61. The comparator 60 uses the output of the horizontal blanking period detection circuit 53 as one input, the I signal as the other input, and the I signal during the horizontal blanking period as a reference, when the I signal amplitude is equal to or more than a certain value, “1”. Is output, and otherwise, "0" is output. The multiplication circuit 61 receives the output of the comparator 60 as one input and the output of the subtraction circuit 59 as the other input, and outputs the multiplication result to the addition circuit 62. The adder circuit 62 receives the output of the multiplier circuit 61 as one input and
The signals are added as the other input, and the contour-compensated I signal is output.

Next, the operation of the color signal contour compensating circuit configured as described above will be described with reference to the waveform diagram of FIG. Since the color signal I and the color signal Q have the same processing operation,
The color signal I will be described. Now, the waveform K1 of the color signal I shown in a in FIG.
It is assumed that the luminance signal waveform K2 shown by b in FIG. The HPF 54 outputs the waveform K3, which is the high frequency component of the luminance signal, shown in c in the figure to the addition circuit 55 and the subtraction circuit 59.
The adder circuit 55 adds the output K3 from the HPF 54 and the I signal K1 and multiplies the waveform K4 indicated by d in the figure by the multiplier circuit 57.
Output to. I signal K1 input to the comparator 56
Performs a voltage comparison using the voltage in the horizontal blanking period as a reference, and the waveform K5 of the comparison result shown in e in the figure is the multiplication circuit 57.
Is output to. The multiplication circuit 57 multiplies the waveform K4 and the waveform K5 and outputs the waveform K6 shown by f in the figure. The rectifier circuit 58 rectifies the waveform K6 and outputs a waveform K7 of its negative component shown by g in the figure. The subtraction circuit 59 subtracts the output waveform K7 from the output waveform K3 of the HPF 54, and outputs the waveform K8 shown by h in the figure to the multiplication circuit 61. As a result, the component in which the hue is inverted is removed by the subtraction circuit 59 in the high-frequency component waveform of the luminance signal by the contour compensation, so that the color shift due to the contour compensation does not occur and the compensation amount can be set freely. it can. This waveform K8 and waveform K
1 is added by the adder circuit 62, and a waveform K9 having steep rising edges and falling edges shown in j in the figure is output. Here, when only the luminance signal is input in the portion having no color signal, the output of the HPF 54 is directly output from the subtraction circuit 59. In order to remove this signal, it is detected by the comparator 60 whether or not the I signal is input, and this output is multiplied by the output of the subtraction circuit 59 by the multiplication circuit 61 to prevent unnecessary leakage of the luminance signal. There is. As described above, in this embodiment, the rectified waveform K7 is used for the color signal compensation.
Therefore, the image quality deterioration due to the color shift that tends to occur near the contour after compensation does not occur.

[0019]

As described above, according to the present invention, the color signal is attenuated by the negative component and is multiplied by the positive component by the polarity of the high frequency component used as the compensation signal, and the compensation is performed by the contour component. There is no associated hue reversal.
Therefore, it is possible to freely select the amplitude of the high-frequency component output by the high-pass filter without the adverse effects of unnatural color changes, and to set the compensation amount of the color signal broadly. It is possible to obtain a clear image. Further, according to the present invention, a component that causes a color shift in the contour compensation performed by the high frequency component of the luminance signal can be removed by the subtraction circuit that subtracts the rectified waveform from the output of the high pass filter. There is an advantage that a clear image can be obtained without any adverse effects. Further, according to the present invention, there is an advantage that it can be configured by using only easily realizable circuits.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a color signal contour compensation circuit according to the present invention.

FIG. 2 is a block diagram showing a color signal contour compensation circuit according to another embodiment.

FIG. 3 is a block diagram showing a color signal contour compensation circuit of still another embodiment.

FIG. 4 is a waveform diagram for explaining the operation of the color signal contour compensation circuit of FIG.

FIG. 5 is a block diagram showing another embodiment of the polarity separating means.

FIG. 6 is a block diagram showing still another embodiment of the polarity separating means.

FIG. 7 is a block diagram showing a color signal contour compensation circuit of still another embodiment.

8 is a waveform diagram for explaining the operation of the color signal contour compensation circuit in FIG.

FIG. 9 is a block diagram showing a conventional color signal contour compensation circuit.

[Explanation of symbols]

 2,12,22,54 HPF 3,13 Polarity separation circuit 5,16 Attenuation circuit 6,15,27,30,57,61 Multiplication circuit 23 Half-wave rectification circuit 24,59 Subtraction circuit 26,29 Electronic volume 53 Horizontal return Line erase period detection circuit 55,62 Adder circuit 55,60 Comparator

Claims (4)

[Claims] 1. A high-pass filter which outputs at least one of a luminance signal or a chrominance signal and outputs this high-pass component, and an output of this high-pass filter which inputs a positive component and a negative component. A polarity separation circuit that separates and outputs, and an attenuation circuit that attenuates and outputs a color signal in proportion to the amplitude of the negative component output with the negative component output of this polarity separation circuit as one input and the color signal as the other input. A color signal comprising: a positive component output of the polarity separation circuit as one input, and an output of the attenuation circuit as the other input to perform multiplication to output a contour-compensated color signal. Contour compensation circuit. 2. A high-pass filter which outputs at least one of a luminance signal or a chrominance signal and outputs this high-pass component, and an output of this high-pass filter which inputs a positive component and a negative component. A polarity separation circuit that separates and outputs, a multiplication circuit that performs multiplication by using the positive component output of this polarity separation circuit as one input and a color signal as the other input, and the negative component output of the polarity separation circuit that is one input And a color signal contour compensation circuit which uses the output of the multiplication circuit as the other input to attenuate the color signal in proportion to the amplitude of the negative component output and outputs the contour-compensated color signal. circuit. 3. A high-pass filter which inputs at least one of a luminance signal or a chrominance signal and outputs this high-pass component, and detects a part or all of a horizontal blanking period of the luminance signal. A horizontal blanking period detection circuit that outputs a detection signal, and the output of this horizontal blanking period detection circuit as one input, the color signal as the other input, and the color signal voltage during the horizontal blanking period as a reference. A voltage comparison circuit for performing voltage comparison of color signals and outputting positive and negative; a first addition circuit for performing addition by using the output of the high pass filter as one input and the color signal as the other input; and A multiplication circuit that performs multiplication by using the output of the adder circuit as one input and the output of the voltage comparison circuit as the other input, a rectifier circuit that outputs the negative component with the output of this multiplication circuit as an input, and the above high-pass filter. A subtractor circuit that subtracts the output of the rectifier circuit from the output of the filter, and outputs the subtractor circuit with one input as the input and the color signal as the other input to output a contour-compensated color signal. A color signal contour compensating circuit comprising: 4. A high-pass filter which inputs at least one of a luminance signal and a chrominance signal and outputs this high-pass component, and detects a part or all of a horizontal blanking period of the luminance signal. A horizontal blanking period detection circuit that outputs a detection signal, and the output of this horizontal blanking period detection circuit as one input, the color signal as the other input, and the color signal voltage during the horizontal blanking period as a reference. A first voltage comparison circuit for comparing the voltage of the color signals and outputting a positive / negative value; a first addition circuit for adding the output of the high-pass filter as one input and the color signal as the other input; The output of the first adding circuit is used as one input, and the first
From the output of the high-pass filter, a first multiplication circuit that performs multiplication by using the output of the voltage comparison circuit of the other as the other input, a rectification circuit that outputs the negative component by using the output of the first multiplication circuit as the input, A subtractor circuit that subtracts the output of the rectifier circuit and a color signal as one input, the output of the horizontal blanking period detection circuit as the other input, and a constant with reference to the color signal voltage during the horizontal blanking period. A second voltage comparison circuit for detecting and outputting the presence or absence of a color signal amplitude equal to or larger than a value, and an output of the second voltage comparison circuit as one input, and an output of the subtraction circuit as the other input for multiplication. A second multiplying circuit; and a second adding circuit that outputs the contour-compensated color signal by adding the output of the second multiplying circuit as one input and the color signal as the other input to perform addition. Color signal characterized by Guo compensation circuit.