Abstract: An angle calculation unit calculates an angle formed by color difference signals R-Y, B-Y of each input pixel. Correction gain calculation units use the angle as a parameter to generate correction gains of hue, chroma, luminance (Y) gamma, and chroma (C) gamma for only correction regions. Accumulators accumulate the respective correction gains. In a circuit including from a multiplier (10) to a multiplier (18), the color difference signals R-Y, B-Y are multiplied by the correction gains of hue and chroma to correct the hue and chroma. A luminance/color difference gamma processing unit uses a correction function and correction gains of Y, C gammas to gamma-correct a luminance signal Y and color difference signals R-Y, B-Y.

Abstract: A method and apparatus for selectively enhancing contrast depending on the level of incoming video signals while preserving colors are provided. An apparatus for enhancing the contrast and brightness of a video signal displayed on a display device includes: a first luminance level transformation circuit that receives luminance and chrominance signals, reduces the level of the luminance signal in response to a first control signal, and outputs the chrominance signals and the luminance signal whose level has been reduced; an image converting circuit that receives the output signals from the first luminance level transformation circuit and converts the received signals into RGB video signals; and a second luminance level transformation circuit that receives the RGB video signals from the image converting circuit, concurrently increases the respective levels of the RGB video signals in response to a second control signal, and outputs the RGB video signals whose levels have been increased.

Abstract: A digital video signal processing system which includes a scaler converting a video signal having a luminance signal and chrominance signals into a digital RGB signal, further including a hue adjusting part adjusting hue represented by the chrominance signals; wherein the scaler includes an operating part operating a rotational transfer matrix rotation-transforming color coordinates of the chrominance signals according to an adjusting value inputted through the hue adjusting part. Accordingly, a digital video signal processing system and method, in which rotational transform of color coordinates is accomplished by a rotational transfer matrix prior to a color transfer matrix of a scaler without a hardware component therefor is provided.

Abstract: The values of the primary color space components of an image signal, such as the components of RGB video signal, are maintained within their allowed range by modifying the signal in a different color space, such as YUV space. Specifically, the U and V chrominance components are attenuated by an attenuation factor g while the luminance component Y is not modified. The value of g is the largest possible value less than 1 that will cause all primary color space components that would otherwise be outside the allowed range to be within that range. A high quality of the displayed image is maintained.

Abstract: The system and software of the present invention presents a process for translating a source palette containing TV unsafe colors into a resultant modified palette containing only TV safe colors, while preserving the color trends in the source palette. The software will first analyze a source color palette to determine the TV unsafe colors contained therein. For each TV unsafe color in the source color palette, the software determines the closest TV safe color by selecting a TV safe color that is the shortest Euclidean distance from the TV unsafe color. The TV unsafe colors are substituted with the calculated TV safe colors and stored in the resultant palette. The software will divide the color space of the source palette into discrete regions, e.g., by Hue (H), by selecting reference colors as the boundaries of the regions. The initially TV safe color will then be modified in a manner similar to the modifications made on nearby reference colors that were required to make them TV safe.

Abstract: If gamut mapping (hue restoration) defined by one Lab color space is applied in color matching under different reference white points, the human vision perceives the hue as inconsistent. In view of this, input data which is dependent on a color space of an input device is converted by the conversion LUT 11 to color space data which is independent of any devices, based on a viewing condition at the time of viewing an input original. The data is converted to data in the human color perception space by the forward converter 12, then subjected to gamut mapping, and converted back to data in the color space independent of any devices by the inverse converter 15, based on a viewing condition at the time of viewing an output original. Then, the data is converted to output data in a color space which is dependent on an output device by the conversion LUT 16.

Abstract: A color television receiver system processes color difference signals for providing tint control while maintaining uniform color amplitude with respect to changes in hue shift angle. The color difference signals are modified as a function of each other and as a function of a hue shift angle to produce modified color difference signals. A color difference signal [B-Y] is supplied as a first input to multipliers M1 and M3. Another color difference signal [R-Y] is supplied as a first input to another pair of multipliers M2 and M4. A control signal generator produces output signals sin ? and cos ? where ? is the hue shift angle. The sin ? signal is supplied as a second input to multipliers M1 and M4 while the cos ? signal is supplied as a second input to multipliers M2 and M3. The outputs of M1 and M2 are added in an adder A1 to produce a modified output [R-Y]?.

Abstract: An apparatus and a method are provided for adjusting real time video to compensate for color blindness. A video system includes a decoder that receives and decodes a video signal into original color signals. A processor receives the original color signals and outputs color signals that are adjusted for compensating for a selected one of a number of precharacterized types of color blindness. A screen receives the adjusted color signals and displays images adjusted from the original to compensate for the selected type of color blindness. The adjusted signals are derived from the original signals by one color gamut adjustment for each type of color blindness. The color gamut adjustments are generated by characterizing at least the known, major color deficiencies, and then generating color gamut transforms to fit more range of actual color contrast within the range of perception of the color blind. Each transform is stored in a memory as a lookup table, and looked up by the processor.

Abstract: An apparatus comprising a first circuit and a second circuit. The first circuit may be configured to present a first portion of an output data stream in response to a first portion of an input data stream. The second circuit may be configured to present a second portion of the output data stream in response to a second portion of the input data stream. The apparatus may be configured to perform color and gamma correction on the input data stream to generate the output data stream in response to one or more control signals. In one example, the apparatus may comprise block move engine (BME).

Abstract: A camera for use with a flash apparatus is capable of achieving excellent color balance when a picture is taken using the flash apparatus. The camera comprises a flash control circuit that controls the amount of light generated by the flash apparatus, and a color adjusting circuit including a linear matrix circuit and a gain control circuit that controls hues or color saturation. A color correcting circuit controls the color adjusting circuit such that the hue or color saturation is properly adjusted in accordance with the amount of light determined by the flash control circuit.

Abstract: A TV encoder with a function of adjusting hue for receiving a first and second color mixture signals comprises a first and second multiplexors, a sin-cos generator, a first and second multiplier circuits, and an adder circuits. The first multiplexor alternately outputs the second color mixture signal and its inverted signal. The second multiplexor alternately outputs a first angle signal representative of an angle and a second angle signal representative of the negative value of the angle. The angle is adopted to change the hue. The sin-cos generator outputs a sin and cos signals with a phase angle alternately determined by the angle and its negative value. The first color mixture signal and the sin signal are multiplied through the first multiplier circuit so as to be output as a first product signal. The second color mixture signal and its inverted signal are alternately multiplied by the cos signal through the second multiplier circuit so as to output as a second product signal.

Abstract: A video signal processing apparatus for processing a video signal containing first and second color difference signals so as to adjust colors of an image represented by the video signal is disclosed. The apparatus includes a plurality of gain setting sections for setting respective ones of gain conversion characteristics. The gain conversion characteristics are relevant to saturations indicated by color difference signals. First and second conversion sections are included for converting gains of the color difference signals based on input values of respective color difference signals and the pain conversion characteristics.

Abstract: A video display interface controller for a host video display unit in which control signals multiplexed with component video signals are extracted and routed according to included address information. Control data associated with one or more local addresses is used for initial processing of the component video signals while control data associated with one or more remote addresses is used for subsequent signal processing.

Abstract: There is disclosed an apparatus for performing segmentation-based enhancements of a video image. The apparatus comprises: 1) an input buffer for storing video frames of an incoming video signal; 2) a segmentation controller capable of segmenting a first stored frame into a plurality of segments, each of the plurality of segments comprising a plurality of pixels having at least one common property; 3) an image processor capable of calculating a probability function associated with at least one pixel in the first stored frame, the probability function indicating a probability that the at least one pixel belongs within a first selected one of the plurality of segments; and 4) an enhancement controller capable of enhancing a parameter of the at least one pixel as a function of the probability function of the at least one pixel.

Abstract: A method and system are provided for controlling tint of component video signals. The system includes a first input for receiving a first component video signal; a second input for receiving a second component video signal; circuitry including a first differential amplifier and a second differential amplifier for receiving the first and second component video signals from the first and second inputs, respectively; a first output connected to the circuitry for outputting a first tint control adjustment signal for the first component video signal; and a second output connected to the circuitry for outputting a second tint control adjustment signal for the second component video signal. The first outputted signal is represented as V+kU?2ckU and the second outputted signal is represented as U?kV+2ckV, where V represents the first component video signal, U represents the second component video signal, k is a constant, and c is a value greater than or equal to zero and less than or equal to one.

Abstract: A method and system are provided for balance control for component video signals. The system and method of the present disclosure allow for adjusting or compensating for possible color encoding errors, as well as allowing individual viewer preferences to be accommodated, in consumer electronics devices, such as high definition monitors and other imaging devices and appliances. The system includes circuitry for receiving the U and V component video signals and outputting balance adjusted component color difference signals Uout and Vout.

Abstract: An image sensing apparatus for a microscope of this invention includes an image sensing unit for sensing an observation image obtained by a microscope and obtaining the observation image, a microscopy technique determination unit for detecting a microscopy technique in the microscope, a chromaticity determination unit for determining chromaticity of the observation image on the basis of the microscopy technique detected by said microscopy technique determination unit, and determining a region where color balance is adjusted in the observation image, and a color balance adjustment unit for adjusting color balance in accordance with a color balance adjustment amount arbitrarily set for the region of the observation image determined by said chromaticity determination unit.

Abstract: The present invention provides an image compensation apparatus, by which a hardware structure is simplified and by which resolution of a remanded color gamut is enhanced when an inputted digital image is compensated to fit the characteristics of a display device. The present invention includes a 3-dimensional look-up table storing 3-dimensional transformation data corresponding to upper n-bits of an input image and a color interpolation unit outputting a final color-transformed image by performing linear interpolation using the 3-dimensional transformation data outputted from the 3-dimensional look-up table and 3-dimensional data corresponding to lower m-bits of the input image.

Abstract: A specific color-adjusting stage adjusts data of an inputted color with respect to a specific color. A total color-adjusting stage adjusts the data of the inputted color with respect to a total color. The specific color-adjusting stage and the total color-adjusting stage are provided in parallel. A composing unit composes linearly an output of the specific color-adjusting stage and an output of the total color-adjusting stage. When a degree that the total color-adjusting stage adjusts the data of the inputted color increases, then a degree that the specific color-adjusting stage adjusts the data of the inputted color decreases, and vice versa.

Abstract: An image processing apparatus operates to process signal samples in a form of color reference signal samples representative of at least part of a color video image to produce legal color signal samples representing a legal color version of the image. The apparatus comprises a color conversion processor arranged to receive the input signal samples and which operates to convert the color reference signal samples from a unipolar form, to bipolar form on a scale between two maxima having opposite polarity, an adjustment factor generator, which operates to generate a plurality of adjustment factors which when combined with the input signal samples have an effect of converting illegal color pixels of the color image into legal color pixels, and a color legalizer coupled to the adjustment factor generator, which operates to combine the adjustment factors with the input signal samples to produce the legalized color signal samples.

Abstract: Display data comprising text and a background are processed. A combination of the text and background is evaluated against one or more objective criteria to provide one or more objective values. A determination is made whether the one or more objective values exceed one or more respective thresholds that are indicative of text-background combinations that are difficult to read. The text or the background or both are adjusted if any of the one or more thresholds is exceeded, so that the one or more thresholds are no longer exceeded after the adjusting.

Abstract: A method of mapping an input color gamut of an input device onto an output color gamut of an output device includes establishing a threshold chroma value in the input color gamut. For first input chroma values below the threshold chroma value, each first input chroma value is mapped onto a respective one of a plurality of first output chroma values such that a first linear relationship exists between the first input chroma values and the first output chroma values. Each corresponding first input lightness value is mapped onto a respective one of a plurality of first output lightness values such that a second linear relationship exists between the first input lightness values and the first output lightness values. For second input chroma values above the threshold chroma value, each second input chroma value is mapped onto a respective one of a plurality of second output chroma values such that a first non-linear relationship exists between the second input chroma values and the second output chroma values.

Abstract: Device and method for decoding a television video signal are suggested. The device includes a tint controller and a color space converter. The tint controller converts a plurality of color space converting coefficients which is used for converting color space signals into R, G, B signals into tint considered coefficients having a tint control considered. On the other hand, the color space converter produces the R, G, B signal displayable on a monitor by using the tint considered coefficients from the tint controller and the color space signals.

Abstract: Hue is controlled using a saturation control circuit. A first color space value is adjusted based on a hue angle and a saturation value, and a second color space value is adjusted based on the hue angle and the saturation value. The first and second color space values are processed to obtain a hue-adjusted color space value.

Abstract: A video signal processing apparatus A comprises: an adder 107 for generating a second address value S106 which has a predetermined phase difference from a first address value S101 outputted by an address value output means 120 and outputting the same; a selector 108 for selecting either a first address value S101 or a second address value S106 to output as an output signal S107; a vertical synchronizing signal output means 123 for outputting the vertical synchronizing signal S104 to the selector 108; a ROM 109 for outputting first data corresponding to the first address value S101 or second data corresponding to the second address value S106 as a signal S108; a loading hold mode flip-flop 110 for preserving the first data; a loading hold mode flip-flop 111 for preserving the second data; and a hue adjustment means B which adjusts the hue of the video signal by using the output signal S109 of the loading hold mode flip-flop 110 and the output signal S110 of the loading hold mode flip-flop 111.

Abstract: A method and apparatus for controlling tint in a digital color display system capable of efficiently performing tint control of displayed colors. The tint control method is executed according to the following: (1) when the maximum and the minimum among R, G, B are the maximum gray scale value and the minimum gray scale value respectively, a step of transforming the input color into a color of a different tint based on a use defined maximum transformation value and a transformation direction; (2) when the maximum and the minimum among R, G, B are Dmax and Dmin respectively, a step of transforming the input color into a color of a different tint based on a smaller transformation value and the same transformation direction; and (3) when all values R, G, B are equal, a step of not transforming the input color in accordance with any input set value.

Abstract: An image processing apparatus operates to process input signal samples representative of at least part of a color video image to produce legal color signal samples representative of a legal color version of the image. The apparatus comprises an adjustment factor generator, which operates to generate a plurality of adjustment factors which when combined with the input signal samples have an effect of converting illegal color pixels of the color image into legal color pixels, an adjustment factor biasing processor coupled to the adjustment factor generator, which operates to change the adjustment factors by combining each of the adjustment factors with a biasing constant, and a color legalizer coupled to the biasing processor, which operates to combine the biased adjustment factors with the input signal samples to produce the legalized color signal samples.

Abstract: The values of the primary color space components of an image signal, such as the components of RGB video signal, are maintained within their allowed range by modifying the signal in a different color space, such as YUV space. Specifically, the U and V chrominance components are attenuated by an attenuation factor g while the luminance component Y is not modified. The value of g is the largest possible value less than 1 that will cause all primary color space components that would otherwise be outside the allowed range to be within that range. A high quality of the displayed image is maintained.

Abstract: An object of the present invention is to provide a gradation correction device which can perform gradation correction using digital feedback processing, and furthermore, can control the digital feedback processing with high accuracy.

Abstract: A color modification system and method for reducing the number of computations performed on a pixel color. This reduction in computations increases the rate at which color modification may be performed and decreases the effects of rounding errors. Decreasing the effects of rounding errors produces a more accurate color modification, thereby reducing the likelihood of artifacts. The system and method performs color modification on a pixel color, where the color includes a first, second, and third component and each component defines a value of the color. The system includes a chroma lookup table having a plurality of entries. Each entry corresponds to a luma value and contains chroma coefficients. The chroma coefficients define color modifications to be applied to the components of the color. If a luma value is received, the chroma lookup table generates output chroma coefficients at an output.

Abstract: A color signal processing apparatus for a multi-primary display with a simple circuit construction and a color signal processing method achieves a display white by more than four display primaries. The color signal processing apparatus has a tristimulus value calculation unit calculating tristimulus values (X, Y, Z) of an input color signal, a display primary control signal calculation unit calculating a control signal of each display primary to represent the color signal with a number of display primaries, and a control unit setting the control signal of each display primary with the control signal calculated by the display primary control signal calculation unit to display the color signal.

Abstract: A high definition display unit which demodulates, decodes, and processes in relation to chroma and displays a television signal in which a PI (picture) signal and an SI (service information) signal are mixed. A changeover switch 13 connected to an image quality adjusting circuit in a video chroma processing circuit 7 is opened or closed according to an on-off signal SI showing the superposed period of both signals detected by a decoder 4. If the above on-off signal SI is on, the changeover switch 13 is opened and the adjustment of image quality is disabled. Therefore, SI display never disappears due to the adjustment of image quality, and the quality of an image can be also adjusted according to an ambient status. Other approaches are also disclosed from preventing image quality adjustment of at least portions of a displayed image containing an information image.

Abstract: A method and system are provided for controlling tint of component video signals. The system includes a first input for receiving a first component video signal; a second input for receiving a second component video signal; circuitry including a first differential amplifier and a second differential amplifier for receiving the first and second component video signals from the first and second inputs, respectively; a first output connected to the circuitry for outputting a first tint control adjustment signal for the first component video signal; and a second output connected to the circuitry for outputting a second tint control adjustment signal for the second component video signal.

Abstract: A video signal processing circuit for making adjustments of a brightness, a contrast, a hue, and the like of a color video signal by a simple circuit construction. Input video signals which are supplied as 3-primary color signals or luminance and color difference signals are converted to the luminance and color difference signals or the 3-primary color signals and processed to effect adjustments of a picture displaying form, and the adjusted signals are inversely converted subsequently.

Abstract: It is an object of the present invention to provide a color conversion apparatus in which an output result of a color converting circuit at the succeeding stage for color-converting a specific color can be prevented from being affected by an output result of a color converting circuit at the preceding stage for color-converting a whole image. Since a first color converting circuit (10) color-converts a whole image of image data in a first color-conversion fashion.

Abstract: An apparatus for creating an ICC profile in a simple manner without using a specialized measuring instrument. A display control unit reads out a dot pattern image from a pattern image data holding unit and a grayscale pattern image containing a plurality of grayscale patches of gradually varying gray scale from a grayscale image data holding unit, and presents the thus readout images for display on a display device. A user selects the grayscale patch having brightness closest to the brightness of the dot pattern image by operating a selection unit. Based on the selection, a gamma coefficient value is calculated by a gamma coefficient value calculation unit, and based on this gamma coefficient value, a profile creation unit modifies the ICC profile held in a common information holding unit and thus creates a customized ICC profile.

Abstract: In a moving image correction system including a client and server that are mutually connected such that data transmission is enabled therebetween over a network, the client analyzes the changes over time in the average value of the moving image that comprises the subject of correction and sends the analysis results to the server, and the server receives the analysis results sent from the client and corrects the data sent from the client based on the analysis results in prescribed units. The server can efficiently perform correction of the moving image by using the analysis results furnished by the client.

Abstract: In a color correcting parameter calculator, a color correcting unit 11 calculates a target color by executing color correction processing of an input color on a reference side while a reference side color perception value calculator unit 13 calculates color perception values of the input color and its target color on the reference side. An object side color perception value calculator unit 15 calculates color perception values of an input color on an object side. A color difference searching unit 16 detects that input color on the reference side which has a minimum color difference with the input color on the object side, by accessing a color perception storage unit 14 for input and target colors for the reference side. A device dependent color unit 17 on the object side calculates device dependent color data of a target color on the object side with reference to perception values of the target color on the reference side while a color correcting parameter calculator 18 calculates color correcting parameters.

Abstract: In a hue adjustment circuit for adjustment of a color difference signal by addition, subtraction, and multiplication of hue correction components (sin &agr;, cos &agr;) generated from a sub-carrier signal and a color difference signal (R—Y, B—Y), the hue correction components (sin &agr;, cos &agr;) are derived from a chroma signal processing circuit in a TV set by using a switch to select between the chroma signal and a phase-shifted sub-carrier.

Abstract: A method and apparatus for transforming color signals. The transformation is achieved by use of a first, coarse, look-up table and a second look-up table that provides coefficients to be used in calculating a correction vector. The vector of color components from the first look-up table is added to the correction vector to provide the transformed vector. The method and apparatus have particular application in the display of digital video signals.

Abstract: In a color digital imaging apparatus, a light source selector is provided for a user to select a proper illumination condition. When down loading the captured image in a computer system, a color correction function is performed at the computer system.

Abstract: A digital camera includes a CCD imager. Image data of an object photographed by the CCD imager is subjected to a color adjustment based on a plurality of first color adjustment values which correspond to a plurality of representative colors and a plurality of second color adjustment values which correspond to a plurality of non-representative colors. If a desired representative color is selected and a dial key is operated, the first color adjustment value of the desired representative color, that is, a desired first color adjustment value is changed.

Abstract: A method, system and computer program product for color conforming video material at a given resolution is provided. The given video material is first converted to a lower resolution version of the same material. Then a color corrected version of the lower resolution version of the video material is obtained. A computer then analyzes the lower resolution version and the color corrected version of the lower resolution version in the same three dimensional color space to determine suitable color values for a color conforming version of the video material at the given resolution.

Abstract: A color modification system and method for reducing the number of computations performed on a pixel color. This reduction in computations increases the rate at which color modification may be performed and decreases the effects of rounding errors. Decreasing the effects of rounding errors produces a more accurate color modification, thereby reducing the likelihood of artifacts. The system and method performs color modification on a pixel color, where the color includes a first, second, and third component and each component defines a value of the color. The system includes a chroma lookup table having a plurality of entries. Each entry corresponds to a luma value and contains chroma coefficients. The chroma coefficients define color modifications to be applied to the components of the color. If a luma value is received, the chroma lookup table generates output chroma coefficients at an output.

Abstract: A color picture display apparatus employs an array of light-emitting diodes or other light-emitting elements emitting different colors. A television signal is converted to monochromatic signals of the different colors. A color converter modifies the monochromatic signals, thereby changing the displayed hues to match the hues that would be displayed on a television screen, to compensate for ambient lighting conditions, or to achieve other desired effects. If each picture element has only a single light-emitting element, the modification preferably avoids unlit gaps in monochromatic areas of the displayed picture.

Abstract: A television system includes a television receiver (11) and a remote control (18, 72). If an RGB bias level adjusting mode is set by the remote control, the CPU (74) disables the ramp waveform generator (36) but enables a brightness component cutoff circuit (58a) and color component cutoff circuit (58b) that are included in an YC mixing circuit (58). In response, vertical deflection is suspended, and a video signal having a pedestal level is outputted onto a display (70). Accordingly, luminescence occurs on the display at a vertically center thereof. Meanwhile, the bias level is adjusted optimal by user's operation of a numeral key provided on the remote control while observing on the display.

Abstract: A signal Y outputted from a Y/C separating circuit is supplied to first and second matrices. Signals R-Y and B-Y are supplied to the first matrix through a gain control amplifier (GCA) and are also supplied to the second matrix. The signals Y, R-Y, and B-Y are converted into three primary color signals R, G, and B by the second matrix. From the signals R, G, and B, a skin color component is detected by a skin color detecting circuit and Eskin is outputted. On the basis of Eskin, color components other than the skin color are detected by a color component detecting circuit and Eother is outputted. Eother−Eskin is supplied as a control voltage to the GCA. Gains for the signals R-Y and B-Y are controlled. When the video signal indicates the skin color component, the control voltage is set to 0 and the gain is set to 1. When the video signal indicates a color component other than the skin color component, Eother is generated, the control voltage rises, and the gain is increased.

Abstract: The invention provides a technique of making color adjustment for a great number of colors among different imaging apparatus. In the process of making color adjustment among a plurality of cameras, a color correction processing unit disposed in a CCU of each camera detects data associated with lightness, hue, and saturation for a plurality of specified colors. The detected data is transmitted as color data to a CPU. According to the color data supplied from each CCU, the CPU divides the color space into a plurality of areas, and calculates setting data which is required by the color correction processing unit to correct the lightness, hue, and saturation. The resultant setting data is transmitted to the color correction processing unit. In actual use in a normal operation mode, the color correction processing unit corrects the lightness, hue, and saturation according to the procedure determined for each area in accordance with the setting data.

Abstract: The system and software of the present invention presents a process for translating a source palette containing TV unsafe colors into a resultant modified palette containing only TV safe colors, while preserving the color trends in the source palette. The software will first analyze a source color palette to determine the TV unsafe colors contained therein. For each TV unsafe color in the source color palette, the software determines the closest TV safe color by selecting a TV safe color that is the shortest Euclidean distance from the TV unsafe color. The TV unsafe colors are substituted with the calculated TV safe colors and stored in the resultant palette. The software will divide the color space of the source palette into discrete regions, e.g., by Hue (H), by selecting reference colors as the boundaries of the regions. The initially TV safe color will then be modified in a manner similar to the modifications made on nearby reference colors that were required to make them TV safe.

Abstract: Red color saturation is increased and red color with higher purity can be reproduced by composing: a red color detection circuit 1 for detecting a red color signal having higher purity by inputting color differential signals (R-Y) and (B-Y) modulated by color subcarrier, subtracting the absolute value of the (B-Y) signal from the positive polarity component of the (R-Y) signal and removing the negative part of the subtracted signal; Y signal compensation block including: first gain controller 50b for controlling the output signal amplitude of red color detection circuit 1 and a subtracter 50a for subtracting the output signal of first gain controller 50b from a luminance signal Y; an (R-Y) signal compensation block including: second gain controller 51b for controlling the output signal amplitude of red color detection circuit 1 and an adder 51a for adding the output signal of second gain controller 51b and the input (R-Y) signal; and a (B-Y) signal compensation block including: third gain controller 52b for c