Abstract: When gamut mapping (hue restoration) defined by one Lab color space is applied in color matching under different reference white points, 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 a first conversion LUT to color space data which is independent of any devices, based on a viewing condition at the time of viewing an input original. The device independent data is converted to data in the human color perception space by a forward converter, subjected to gamut mapping, and converted back to device independent data in the color space independent of any devices by an inverse converter, based on a viewing condition at the time of viewing an output original. Then, the device independent data is converted to output data in a color space which is dependent on an output device by a second conversion LUT.

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 chrominance signal processing apparatus in a video signal processing system which has a simple configuration capable of achieving chrominance signal control and RGB transform functions using a single circuit.

Abstract: In a signal processing apparatus for processing an image signal, a hue difference between adjoining pixels is detected by a color image edge detector, and an aperture control main gain circuit amplifies a luminance signal using a gain determined on the basis of the hue difference detected by the color image edge detector to enhance an edge pixel of an image.

Abstract: An image processing circuit generates first and second color difference data U/V from image data which includes first, second and third complementary color data. The complementary color data each represent a respective complementary color of the primary colors (R,G,B). The circuit includes a distribution circuit that distributes the image data into the first to third complementary color data. A multiplication circuit multiplies combinations of the complementary color data to generate first to third products. A subtraction circuit subtracts one product from another to generate first and second difference values. A square root circuit calculates the square root of the absolute value of the first and second difference values to generate first and second root values. First and second polarity codes, which indicate the polarity of the first and second difference values, are added to the first and second root values to generate first and second polarized roots.

Abstract: The color reproduction correction circuit which corrects the color distortion caused when color signals using the first combination of the three primary colors are reproduced in a color display of the second combination of the different primary color sources has been disclosed, wherein: a provided color correction circuit generates the mixed color signal by multiplying the color signal in question by the specified coefficients and adding the mixed color signal to other color signals; the mixed colors in the second combination are used as primary color light sources in the second combination; the specified coefficients are determined so that these mixed color light sources are made close to the coordinates of the primary color light sources of the first combination; and the luminescent chromaticity values of the three primary colors are corrected so that the chromaticity values of the device match those specified by the signal system.

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: The invention provides an image color correction apparatus by which a hue in a desired region in a color image can be corrected to a desired hue readily. Based on a hue and a hue range designated, a color approximation degree hx of each of noticed pixels of input pixels of an input signal is calculated, where HSV values are represented by (h1, s1, v1), in accordance with hx=((m−|Hue−h1|)/m)×s1×v1, and where correction coefficients of color signals R, G and B of each of the input pixels are represented by (a1, a2, a3), the color signals (R, G, B) are corrected to (R′, G′, B′) so that the corrected color signals (R′, G′, B′) may satisfy (R′, G′, B′)=(R, G, B)+hx×(a1, a2, a3).

Abstract: A color video apparatus for displaying on-screen a hue control state of a color video signal. The apparatus includes a key input portion for inputting a hue control command of the color video signal displayed on the screen, and an on-screen-display (OSD) signal generator for generating an OSD signal for visually representing a reference color and for displaying an occupancy which indicates the degree to which the reference color contributes to the expression of a hue control state with respect to a plurality of reference colors used for expression of the hue control state, in response to the hue control command of the key input portion.

Abstract: Color display pixels taken in localized groups are transformed from RGB color signals intended for a self-luminous display into WCMYRGBK signals to drive a chromatophore color display device. Each chromatophoric pixel is of one solid color and is selected from the group (White, Cyan, Magenta, Yellow, Red, Green, Blue, Black). Input luminosity resolution is maintained as output brightness resolution and color fidelity is preserved for the localized group. Separate totals are developed for the Red, Green and Blue components of pixels in a pixel group. A step-repeat process selects a specific chromatophore color for each pixel. As a pixel of the group is processed a chromatophore color is selected which best matches pixel color and the RGB components of the selected chromatophore color is subtracted form the group color totals. Very bright pixels are represented by White, light pixels are represented by Cyan or Yellow or Magenta, dark pixels are represented by Red or Green or Blue.

Abstract: An analog/digital color video apparatus for adjusting attributes of a color image contained in an analog video signal and a digital video signal and visually displaying an attribute-adjusted color image on a display is provided. When an attribute of an analog video signal having a relatively lower definition is adjusted, the analog/digital color video apparatus converts the analog video signal into a digital signal and adjusts the attribute of the digitized video signal. When an attribute of the digital video signal having a relatively higher definition is adjusted, an attribute of a color image contained in the digital video signal is adjusted without a supplementary signal conversion process such as A/D conversion and D/A conversion. Thus, the analog/digital TV prevents quantization noise which can be occurred in the process of adjusting attributes of the color image.

Abstract: By reducing the saturation (amplitude) at changes in the hue (phase) of the chrominance subcarrier of a video signal, the phenomenon of "dot crawl" can be substantially reduced for graphic data. It has been found that large hue (phase) changes associated with graphic data can cause large frequency shifts of the chrominance subcarrier resulting in a substantial portion of the chrominance subcarrier being unsuppressed by the chrominance subcarrier rejection filter of the luminance decoder. By reducing the saturation during the hue transition, the intensity of the spurious luminance information of the non-suppressed chrominance subcarrier is reduced.

Abstract: An image signal processor generates color difference output signals from color component signals representative of image data. The image signal processor includes multiple color calculators that generate multiple sets of primary color signals from the color component signals. Multiple color difference calculators connected to the color calculators generate multiple sets of color difference signals using the respective sets of primary color signals. A synthesizing circuit combines the multiple sets of color difference signals using a predefined ratio to generate the color difference output signals. By generating multiple sets of signals, errors due to noise can be filtered and higher quality images produced.

Abstract: This invention relates to the color matching function used in connection with the luminance or white stretch function in a television video processor. Automatic adjustment in the amplitude of the color difference signals is provided to compensate for the effect of the stretch of the luminance signal in a provision called color matching. The general principal of color matching being, any percentage change in the amplitude of the luminance signal due to the white stretch effect, must be balanced by the same percentage changes in the color difference signal so that the ratio of the color signals can be maintained after matrixing. This accomplished by compensating the color difference signals by a varying amount that decreases with increasing the input luminance signal level when the level of the input luminance signal is above said selected threshold.

Abstract: An automatic exposure control apparatus comprises a skin color extracting circuit for extracting a skin-colored portion from an input video signal and a focus condition detecting circuit for detecting a focus condition of the skin-colored portion. Exposure is controlled based on outputs of the two circuits. That is, when a skin-colored portion is extracted and it is detected that the skin-colored portion is in an in-focus condition, exposure is controlled so as to be appropriate with respect to the skin-colored portion. A skin color correction unit can correct colors corresponding to the skin color from the video signal.

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

Abstract: A color signal adjustment circuit used in, for example, a camera device, in which specified color signals can be adjusted and, in addition, color signals can be adjusted with a smaller information volume. A chroma SIO 41 generates a pre-set control signal, under control by a micro-computer 50 subject to a setting operation on an operating unit, and judges, at the time of conversion of the color difference signal in the phase/gain control circuit 36, if the phase processing or gain processing is carried out, which of the (R-Y) signal and the (B-Y) signal is controlled and in which quadrant the color adjustment is made, in order to send X and Z signals meeting with these judgment conditions to a phase/gain adjustment circuit 36B pixel-by-pixel. The phase/gain adjustment circuit 36B generates (R-Y) and (B-Y) signals from (R-G) and (B-G) signals based on the X and Z signals.

Abstract: A color image enhancement device for a video display appliance capable of improving the sharpness of the color image using a saturation component. The device includes an RGB (red, green, blue)/saturation conversion section for obtaining a saturation of an image of an RGB color model, a saturation enhancement section for emphasizing a high frequency band of the saturation outputted from the RGB/saturation conversion section to enhance the saturation, and a saturation/RGB conversion section for converting an output of the saturation enhancement section into enhanced color signals.

Abstract: A method of digitally processing a sequence of video frames wherein in object which appears in the frames and undergoes relative motion or transformation is selected in a first frame by an operator; the pixels relating to the object are tagged in that frame by means of information including at least one color or appearance attribute; corresponding pixels relating to the object are located automatically in subsequent frames, by means of said information including at least one color or appearance attribute and by means of information indicating the expected position or shape of the object in the subsequent frames; and the pixels relating to the object in each of the frames are procesed.

Abstract: A tone correction apparatus corrects the tone of an input color image signal independently of each of a plurality of hue areas divided by a plurality of standard axes passing through a plurality of standard colors set on a hue coordinate system. The tone correction apparatus judges whether the hue of an input color image signal belongs to which one of first and second auxiliary hue areas, the first and second auxiliary hue areas being one of the plurality of hue areas divided by an auxiliary standard axis of an auxiliary standard color, and if the hue of the input color image signal is judged to belong to one of the first and second auxiliary hue areas, independently performs tone correction of the input color image signal with respect to color components along one standard axis of the plurality of standard axes surrounding the one auxiliary hue area to which the hue of the input color image signal belongs and along the auxiliary standard axis.

Abstract: In a video encoder, the color distortion between pixels can be reduced by encoding the hue transition to limit very large hue (phase) transitions and encode a corresponding smaller phase transition. This produces fewer spurious colors between pixels during the encoding. This can be done by comparing the change in hue value to a reference value and adding or subtracting 2 .pi. to this reference value to reduce the absolute value of a modified delta hue signal.

Abstract: An apparatus for processing a video signal by adjusting the contour of a picture. The apparatus includes an arrangement from a delay circuit 2 to a subtraction circuit 5 for extracting a contour of the picture and generating at least a signal opposite in polarity to a contour enhancement signal enhancing the extracted contour. The signal polarity is continuously varied from a maximum value of a positive polarity to a maximum value of an opposite polarity by a variable resistor RV2, an output of which is added to the input video signal by an addition circuit 6. With the processing apparatus, a picture can not only be raised in resolution as felt by the viewer, that is can be enhanced in contour, but also can be lowered in resolution as felt by the user, that is can be softened in contour. A corresponding method for processing a video signal by adjusting the contour of a picture and a video camera having the apparatus for processing the video signal in this manner are also disclosed.

Abstract: A device for processing video signals includes a noise reduction arrangement and a contour correction arrangement. To improve color correction, a color correction arrangement (11) is arranged between the noise reduction arrangement (10) and the contour correction arrangement (12).

Abstract: There is provided a signal processing apparatus for processing input three primary color signals, which is capable of providing natural color reproduction. Input color signals R to B are subjected to a matrix operation to obtain color difference signals (R-Y)0 and (B-Y)0. The color signals R to B are compressed by means of high luminance compression circuits 12R to 12B, respectively, and these output color signals R1, G1 and B1 are subjected to obtain a luminance signal Y1, color difference signals (R-Y)1 and (B-Y)1. The respective outputs obtained from the matrix operation are operated by means of look-up tables 43 to 45 and 52 to obtain color difference signals (R-Y)3 and (B-Y)3 for representing a color which has the same hue as a hue .theta. 0 of color represented by color signals R to B and a saturation same with the saturation r1 of color represented by color signals R1, G1 and B1.

Abstract: The invention relates to a device for correcting the tone of color pictures recorded by a video camera, in particular an endoscope camera. A control device, which may also be part of a digital video camera, comprises a memory for storing a table which indicates a characteristic adjusting curve for tone correction values. The control device may further comprise an interface for inputting one or more characteristic adjusting curves according to the field of application of the device according to the invention. A simple rotary transducer which is connected via a lead to a control device serves as the input medium for the tone correction. After activating an automatic white balancing by way of a key connected to the control device, the correction values lies at the white point. The white point is always located on the adjusting curve and serves as a starting point.

Abstract: An apparatus for processing a video signal by adjusting the contour of a picture. The apparatus includes an arrangement from a delay circuit 2 to a subtraction circuit 5 for extracting a contour of the picture and generating at least a signal opposite in polarity to a contour enhancement signal enhancing the extracted contour. The signal polarity is continuously varied from a maximum value of a positive polarity to a maximum value of an opposite polarity by a variable resistor RV2, an output of which is added to the input video signal by an addition circuit 6. With the processing apparatus, a picture can not only be raised in resolution as felt by the viewer, that is can be enhanced in contour, but also can be lowered in resolution as felt by the user, that is can be softened in contour. A corresponding method for processing a video signal by adjusting the contour of a picture and a video camera having the apparatus for processing the video signal in this manner are also disclosed.

Abstract: An apparatus and method for updating a color look up table and expanding video data for use in various applications such as a multimedia computer. The color look up table updating scheme permits selective updating of one entry in the table or up to all of the entries in the table. Updating of the color look up table is preferably performed during the horizontal blanking period. The table may be comprised of two buffers, and a combined output of these two buffers further enhances a multiplicity of colors available to a user.

Abstract: An arrangement for increasing saturation of colors in a color television signal while maintaining fleshtone colors at a same level, the arrangement including a circuit for detecting color signals in a color television signal, circuitry for discerning fleshtone color signals in the detected color signals, a circuit for measuring signal levels of the detected color signals other than the discerned fleshtone color signals, and a circuit for increasing the signal levels of the detected color signals other than the discerned fleshtone color signals in dependence on at least one of the measured signal levels.

Abstract: A method of adjusting hue in color video signals partitions the region of all available hues into subregions in accordance with the signs of U and V components of input color video signals, which U and V signals are respectively proportional to blue-minus-luminance and red-minus luminance color-difference signals. The hue in each subregion is adjusted independently of the hues in the other subregions. Within each subregion, each of the U and V components of the input color video signals that fall therein is gain-adjusted by prescribed factors according to the subregion. A hue adjustment device determines from the signs U and V components of input color video signals which of the subregions they fall into, and adjusts the hue in each subregion to facilitate more accurate hue adjustment.

Abstract: A digital converter controllably modifies input video data representing pixel luminance and color information, in two color space formats. Two color space converters are coupled in cascade. Serial video data is converted to parallel and demultiplexed. A first color space converter converts 4:2:2 sampled YCbCr luminance and color difference input data to RGB red/green/blue format. A second color space converter changes the data back to YCbCr before remultiplexing at the output. Under operator control from front panel inputs, a controller varies the conversion coefficients at the input-side color space converter, including by trigonometric functions applied to the coefficients to provide controllable hue phase shifting, modifies the transfer function in RGB color space by adjusting data in the lookup tables, and applies maximum/minimum clipping levels.

Abstract: A knee circuit in which the hue on the output side does not differ from the hue on the input side. The knee circuit includes a virtual luminance signal generator for generating a virtual luminance signal Y based on at least one input color signal Rin, Gin and Bin, a virtual correction value generator for monitoring whether the virtual luminance signal Y is equal to or greater than a knee point NP and for generating a virtual correction value Yk by performing a knee correction with respect to the virtual luminance signal Y when it is equal to or greater than the knee point NP. A proportional value generator generates a proportional value Kk showing a ratio of the virtual correction value Yk to the virtual luminance signal Y by dividing the virtual correction value Yk by the virtual luminance signal Y.

Abstract: The present invention provides color conversion apparatus that prevents overflow in color reproduction, changes in hue, and the deterioration of gradation to improve image quality. The present color conversion apparatus inputs to itself luminance and color difference signals, sets a reference value not less than the maximum level of the luminance signal, converts the luminance and color difference signals into primary color signals, detects the maximum value of the primary color signals for each pixel, lowers the levels of the color difference signals if the maximum value is over the reference value to locate the amplitude of the primary color signals not greater than the reference value.

Abstract: An image processing apparatus of this invention has an ordinary displaying mode and a hue conversion mode to change hues in correspondence with a user. In the ordinary displaying mode, input image data is displayed on a display, and in the hue conversion mode, an image for hue conversion is displayed on the display. The hues are converted in accordance with an instruction of the user.

Abstract: The present invention provides color conversion apparatus that prevents overflow in color reproduction, changes in hue, and the deterioration of gradation to improve image quality. The present color conversion apparatus inputs to itself luminance and color difference signals, sets a reference value not less than the maximum level of the luminance signal, converts the luminance and color difference signals into primary color signals, detects the maximum value of the primary color signals for each pixel, lowers the levels of the color difference signals if the maximum value is over the reference value to locate the amplitude of the primary color signals not greater than the reference value.

Abstract: It is an object to avoid suppression of color signals before a green color signal G reaches a saturation detection level Gdet or before each of color signals R and B reaches its saturation level to thereby substantially faithfully reproduce color of an object. To this end, a high luminance color suppressing circuit includes a virtual luminance signal generator for generator for generating a virtual luminance signal Y based on at least one signal of input color signals Rin, Gin and Bin, a coefficient generator for generating a first through a third coefficient K.sub.1 through K.sub.3 based on a saturation detection level Gdet, a virtual detection level Gth, and maximum output levels Rmax and Bmax, and an output color signal generator for generating output color signals Rout, Gout and Bout based on the virtual luminance signal Y, a minimum coefficient K.sub.0 and the color signals Rin, Gin and Bin.

Abstract: A color video camera includes a CCD, and digital signals of 4 lines produced on the basis of an outputs from the CCD are applied to a selection circuit which selectively outputs digital signals of 3 lines. A horizontal interpolation circuit and a vertical interpolation circuit perform interpolation calculation on the basis of the digital signals, and outputs a plurality of horizontal color signals and a plurality of vertical color signals, respectively. A horizontal correlation detection circuit and a vertical correlation detection circuit evaluate a horizontal correlation value and a vertical correlation value of a specific pixel with respect to pixels around the specific pixel.

Abstract: A video photometric color sensing system is provided for characterizing the color of a homogeneous substance on a real time basis. The sensing system includes a sample port for holding a homogeneous substance and a camera quantifies a color video image of the homogeneous substance and provides as outputs analog voltage signals representative of the amount of red, green and blue in the color video image. A peak detector circuit receives the analog voltage signals representative of the amount of red, green and blue in the color video image and generates peak red, green and blue analog voltage signals and uses these individual voltage values of each component to derive the luminance value from software generated nonadditive matrix.

Abstract: This invention is related to a video signal color correction device. Color information signal inputs are received in rectangular form. A coordinates conversion means converts the inputs into polar coordinates using one of the inputs as a polar axis. The device has a correction data storing means in which are stored luminance signal correction data dependent on a luminance signal and the polar coordinates and color information signal correction data. The correction data storing means outputs the luminance signal correction data and the color information signal correction data in accordance with the luminance signal and the polar coordinates. A correction means corrects the luminance signal and the polar coordinates on the basis of the luminance signal correction data and the color information signal correction data output from the correction data storing means.

Abstract: Methods of correcting color images often involve a complex interrelation of many color components and require extensive training to be able to be fully utilized. The present disclosure involves a simplified form of color correction. From the selection of a series of actual (16,17) and desired (18,19) colors, a series of contrast and brightness values are derived, which can then be applied to the color image to produce the color corrected image.

Abstract: A digital color correction system and method for correcting a color video signal representing a portion of a colored optical image by modifying the entire color space of each of the complementary colors which make up the color signal so that all objects which contain each color are modified at once. A correction means produces an output video signal having a plurality of complementary color components, each of which is related to a corresponding color component of the color video signal by a transfer function, and a modification means for independently modifying each of the transfer functions is provided. The entire color space for each color may be modified, or only selected portions of it. Thus, only objects falling within a desired range of the color space may be selectively modified.

Abstract: A digital video processor which is usable as a secondary digital color processor (DCP) with standard-definition digital telecines and is also compatible with high-definition television systems, for correcting video color and other attributes such as pixel location and sharpness. The disclosed video processor has an architecture in which only the pixels and/or regions of a video picture to be modified have any processing applied to them, so that most pixels, which are unmodified, remain free from any potential corruption. It identifies pixels to be modified by means of lookup tables which can be loaded for each frame with data indicating attributes such as hue, saturation, and luminance values or ranges which are to be present in a pixel if that pixel is to be selected for modification, the pixel's attributes being applied to each lookup table as an address.

Abstract: Automatically fine tuned pictures and sounds can be obtained from a novel color television system having a video/audio signal adjusting circuit, a remote controller operable for generating a program mode selection signal, a memory having a plurality of memory locations for storing operating parameter data for the video and the audio processing circuit corresponding to program modes, a microprocessor responsive to the program mode selection signal for receiving the operating parameter data corresponding thereto and for generating an audio control signal and a video control signal, a video signal adjusting circuit responsive to the video control signal for adjusting the video signal to have a video characteristic corresponding to the program mode selection signal, and an audio signal adjusting circuit responsive to the audio control signal for adjusting the audio signal to have a frequency band characteristic corresponding to the program mode selection signal.

Abstract: A television projection system for generating picture points of a television picture has at least three light sources which may be controlled in intensity for light signals (R.sub.L ', G.sub.L ', B.sub.L ') of different wavelengths, wherein the hue of each picture point is fixed by means of color value signals (R, G, B) in a first base system which may be represented in a CIE diagram by corner points of a hue region which are defined via wavelengths of screen phosphors. The wavelengths of the light signals determine a second base system which shares a common range of hues with the first base system. Further, an input circuit is provided for generating at least three electrical signals which are proportional to the color value signals (R, G, B) or contain a mixture thereof, and a control device is provided for controlling the light sources.

Abstract: Memories are provided for correction signal values respectively for a hue signal, a saturation signal and a luminance signal derived from a digital color television signal. Each of the memories consists of two memory units which are alternately used for storing new correction signal values and for reading out previously stored correction signal values. The corrected signal values are modified by a key signal, if present, in each case and are then supplied to calculation circuits to each of which a signal derived from the saturation signal is applied. The resulting fully corrected hue and saturation signals are converted back into color difference signals, but the finally corrected luminance signal requires no conversion. The raw correction signal values are supplied from a computer into which control magnitudes can be entered to produce them. These control magnitudes can be used to define corner points of a deflected line function from which the correction signals are derived.

Abstract: Tint detection circuit for automatically selecting a desired tint in a video signal, including a limit signal generator coupled to receive first (R), second (G) and third (R) color signals in order to generate first and second limit signals (CRITR, CRITB); a color-difference generator coupled to receive the first (R), second (G) and third (B) color signals in order to generate first and second color difference signals (G-R, G-B); and a window comparator coupled to the limit signal generator and to the color-difference generator in order to determine whether the first and second color difference signals (G-R, G-B) are within the windows determined by the first and second limit signals (CRITR, CRITB) so as to supply a tint detection signal.

Abstract: A circuit for detecting a specified color in a color image signal operates on first, second and third primary color signals from a color camera. A complementary color, resulting from additive mixing of two primary colors, is detected by taking the sum and differences of the signal representing the two primary colors. The third primary signal is subtracted from the sum signal to produce a vector sum signal and the difference signal is rectified. The signal which indicates the presence of a complementary color is generated by subtracting the rectified signal from the vector sum signal and comparing it to a fixed reference level. A primary color is detected by subtracting the sum signal from the third primary signal to produce the vector sum signal. Fine adjustment of the target color is obtained by amplifying the two primary color signals differentially to maintain a constant sum of the two primary color signals.

Abstract: A color display apparatus for a video information system includes an input for receiving at least one externally applied color component signal, a display device having predetermined color characteristics, and a compensating unit responsive to the at least one externally applied color component signal from the input for compensating at least a portion of the at least one externally applied color component signal in accordance with the predetermined color characteristics of the display device. The display device is responsive to the input and the compensating unit for displaying a color image of the externally applied color component signal.

Abstract: An improved method and apparatus for color correction normalizes two of the three color signals as a function of the third. In the preferred embodiment, an image comprising red, green and blue (RGB) signals are converted to a luminance Y signal, a saturation signal and a hue signal. The luminance and saturation signals are normalized as a function of hue. In the most preferred embodiment, for all fully saturated colors, the luminance values are normalized to a value of 0.5, and the saturation values to unity for all values of hue. The normalized values of saturation and luminance are utilized with the hue value in a secondary color corrector. The color corrected values of saturation and luminance are denormalized as a function of color corrected hue. Optionally, the color corrected luminance, saturation and hue may be converted to RGB signals for output. In one aspect of this invention, the normalized luminance signal is not used for relatively small values of saturation.

Abstract: In a method for correcting flesh color including the steps of generating an I-axis component and Q-axis component of a color-difference signal from R-Y, G-Y, and B-Y color-difference signals; generating a flesh color correction signal on the basis of the generated I-axis and Q-axis components; and correcting the B-Y color-difference signal by the generated flesh color correction signal, the R-Y color-difference signal level is detected, and correction of the B-Y color-difference signal by the flesh color correction signal is inhibited, when the detected R-Y color-difference signal level is higher than a predetermined value.

Abstract: A line locked digital color demodulator separates the V and U color components and the burst signal and uses a ROM for providing phase shifts to the V and U demodulation axes. During the burst time of an NTSC signal, the color component axes are shifted by 45.degree. such that the burst signal produces equal components along the axes. A correction signal is developed in response to this shifting and is used in conjunction with a frequency error signal for continuously addressing the ROM. The error signal is developed by counting the number of clock pulses over a 16 line period and comparing the number counted with a standard number for the type signal being received. The error signal is combined with the correction signal for adjusting the phase of the V and U demodulation axes. For a PAL signal, the burst is normalized to always be at 135.degree. and its components along the V and -U axes are compared as with the NTSC signal.