Abstract: Of three-color signals R′, G′ and B′, obtained as output signals of multipliers 156R, 156G and 156B, designed to effectuate luminance compression of the three-color signals R, G and B sent to input terminals 151R, 151G and 151B by multiplying the signals R, G and B with a coefficient k, in such a manner as to maintain saturation and color hue of the three-color signals R, G and B, only the saturation of color video signals represented by the three-color signals R′, G′ and B′ is compressed by first saturation compression circuits 160R, 160G and 160B so that the signal level of the signal of the three-color signals R′, G′ and B′ having the highest signal level will be the clip level.

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: 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: A level compression and/or gradation conversion of a video signal are performed without causing any change in the hue of a picture represented by that video signal. The knee compression and/or gradation conversion are carried out by multiplying red, green and blue primary color signals by a luminance gain, while the hue and saturation remain unaffected. If the level of any of the primary color signals still exceeds a predetermined threshold level, the saturation conversion is executed by using the saturation gain and the luminance component supplied from a controller. In the saturation conversion operation, the maximum level of at least one of the red, green and blue primary color signals is made coincident with the predetermined threshold level while the hue and luminance of the picture represented by the video signal are maintained unchanged.

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: Disclosed is an image processing method of expanding the dynamic range by determining a saturated or noise region in an image signal and replacing the image signal with a proper image signal. A threshold value is set in units of colors on the basis of a standard image signal for each color, which is obtained upon sensing an image in a standard exposure, and a non-standard image signal for each color, which is obtained upon sensing the image in a non-standard exposure. A saturated or noise region is determined by applying the threshold value set in units of colors to the standard image signal. A region determined as a saturated or noise region is replaced with the non-standard image signal.

Abstract: In data processing wherein image data are processed by dividing them into blocks, a chroma data W is obtained from the color difference data W.sub.R and W.sub.B, and the color difference data W.sub.R and W.sub.B are corrected according to an amplitude of the chroma data W. For example, if the chroma W is smaller than a prescribed threshold value, the color difference data W.sub.R and W.sub.B are set as zero. Then, the so-called block distortion can be prevented. The degree of the correction may depend on the amplitude of the chroma data W. On the other hand, DC coefficients of discrete cosine transform coefficients of adjacent blocks are compared with each other. When the DC coefficients are different from each other, block distortion occurs if they represent a same image. Then, if differences of DC coefficients of discrete cosine transform coefficients of adjacent blocks are small with each other, the DC coefficients are corrected to tend to have similar values.

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: An apparatus for correcting a chromaticity diagram by a variable brightness includes: a first grid voltage controller for controlling a first grid voltage to be a voltage of a predetermined level; a first grid voltage detector for detecting the first grid voltage output by the first grid voltage controller; a phase inverter for inverting a phase of a voltage signal detected by the first grid voltage detector; an analog-to-digital converter for converting the inputted voltage signal, which has been phase-inverted by the phase inverter, into a digital signal; a microprocessor for receiving the digital data of the first grid voltage output from the analog-to-digital converter to produce and output error data; a digital-to-analog converter for converting the error data supplied from the microprocessor into an analog signal, and a cut-off controller for receiving the analog signal output from the digital-to-analog converter and correcting a color-difference signal.

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: A color correction device is disclosed for correcting color distortion in a displayed television image. Internal circuitry of a television receiver has a color signal distortion characteristic, and the cathode ray tube (CRT) in the television receiver has a gamma characteristic according to which display color is distorted. The color correction device includes an average luminance level calculator for calculating the average luminance level of an image signal displayed by the CRT. Based on the average luminance level calculated by the average luminance lever calculator, a selection is made of appropriate sets from a plurality of available sets of coefficient correction values and a plurality of sets of gamma correction values. The color signal input to the television receiver is then corrected according to the selected sets of coefficient correction values and gamma correction values.

Abstract: A device for regulating the luminance signal and chromanance signals of a video image to be converted into red, green and blue color signals. The device includes a conversion matrix and a device for regulating an amplitude of the luminance signal, the blue color difference chromanance signal and a red color difference chromanance signal to be modified by a user adjustment control. The device further includes a device for preventing the color signal having the highest value at the output of the conversion matrix from being able to exceed a saturation value substantially equal to a percentage, preferably 70%, of the white level of the image signal when the color signal reaches the saturation value.

Abstract: Physiological primary colors, which correspond to tristimulus values of each of picture elements of an image on a hard copy, are obtained. A parameter, which represents the degree of incomplete chromatic adaptation, is determined in accordance with a correlated color temperature of a white point of a CRT display device, on which the image is to be displayed. Temporary tristimulus values, which are to be reproduced on the CRT display device, are derived in accordance with the parameter. From the temporary tristimulus values, perception values relating to lightness, color vividness and hue, such as metric lightness, metric chroma, and a metric hue angle in the LAB-color space are calculated by taking the white point of the CRT display device as a viewing illuminance. The tristimulus values of the image are then transformed into the tristimulus values on the display device, and a soft copy image is formed on the display device in accordance with the transformed tristimulus values.

Abstract: In a color processing method and apparatus therefor using two-dimensional (2-D) chromaticity separation for minimizing color difference between an original image and a reproduced image in a color apparatus including a color television receiver, the apparatus includes an index calculator for calculating indexes for projecting R, G and B color signals or luminance signal (Y) and color difference signals (R-Y and B-Y) in a 3-D color space onto a 2-D chromaticity plane, a first look-up table in which the indexes are stored, a second look-up table in which matrix transformation coefficients which define an input-versus-output relationship between the R, G and B color signals or luminance signal (Y) and color difference signals (R-Y and B-Y) are stored and for outputting a predetermined number of transformation coefficients stored in the corresponding address designated by the output signal of the first look-up table, and a color transformation operation unit for receiving the predetermined number of transformation

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 constant luminance corrector for a television system determines brightness information that is discarded in the chrominance channels of an encoder, and adds it to the luminance channel of the encoder. Gamma-corrected luminance and chrominance component signals from a video source, such as a video camera, video tape recorder or the like, are input to the encoder which outputs an encoded luminance component signal and an encoded chrominance component signal that are combined to form a composite signal. The gamma-corrected component signals also are input to a luminance predictor circuit, or alternatively in lieu of the gamma-corrected chrominance component signals a coded chrominance signal and a discarded chrominance signal from the encoder may be input to the luminance predictor circuit. Likewise the encoded luminance component signal may be input to the luminance predictor circuit in lieu of the gamma-corrected luminance component signal.

Abstract: A method for detecting color burst signal amplitude of a composite color image signal for use in an automatic color control circuit includes the steps of separating the burst signal loaded on the chrominance signal into first and second chrominance reference signals having a predetermined phase difference with respect to each other using a carrier signal having an arbitrary burst signal, detecting the squared components of the separated first and second chrominance reference signals respectively, and outputting the amplitude value of the burst signal using a composite signal of the squared components of the detected first and second chrominance reference signals. An apparatus using this method can detect the level of the burst signal regardless of the phase difference between the burst signal and the demodulated carrier.

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: A subject color and a non-subject color of color change operation are specified and then a first color vector representing the subject color and a second color vector representing the non-subject color are obtained. A substitute color for replacing a component of the subject color is further specified, and a color vector representing the substitute color is obtained. A third color vector independent of the first and second color vectors is further determined. A color of each pixel in an original color image is expressed by linear combination of the first through third color vectors, thereby obtaining first through third coefficients for the first through the third color vectors. If the first coefficient is positive, the first color vector is replaced by the substitute color vector. The pixel color after the color change operation is then determined by producing a composite vector using the first through the third coefficients.

Abstract: A signal level adjusting circuit for performing adjustment of signal levels in which the levels of individual image signals are made uniform so as to provide greater use of a dynamic range on an image sensor without deterioration to resolution.

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: Control circuits for the cut-off and drive control of video equipment. A first control device includes a cut-off control circuit and drive control circuit for use in conventional modes. A second control device includes a cut-off control circuit for mode switching and a drive control circuit for mode switching, independent of the first control device. The cut-off and drive adjustments made for every mode switching operation are unnecessary, and the mode switching based on off set data is possible.

Abstract: A dynamic range and contrast modification method for electronic images, and digital and analogue implementations are disclosed. Dynamic range changes are accomplished by making linear and nonlinear modifications to the low frequency component. Contrast changes are accomplished by making cross dependent, linear, and nonlinear modifications to the high frequency component. Cross dependent modifications are modifications that depend upon the changes to the low frequency component. Modifications are achieved using processor elements that implement mathematical operations. An automatic gain control, AGC, is used to control the low frequency component modification for some embodiments.

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: A video signal processor controls aperture correction of the video signal by detecting the occurrence of particular colors in the image produced by the video signal. The particular color, for example, fleshtone, is detected as a ratio of the amplitude of an in-phase color signal and the magnitude of its corresponding quadrature phase color signal. This defines a range of color phases which are classified as the particular color, regardless of their saturation. The detected color is converted into a control signal which changes the amplitude of the aperture correction signal. In one embodiment the control signal has a value of zero if the detected color is within the range of color phases and a value of one otherwise. This control signal is used as a multiplier for the aperture correction signal. In another embodiment, a second range of colors is defined around the defined range.

Abstract: In data processing wherein image data are processed by dividing them into blocks, a chroma data W is obtained from the color difference data W.sub.R and W.sub.B, and the color difference data W.sub.R and W.sub.B are corrected according to an amplitude of the chroma data W. For example, if the chroma W is smaller than a prescribed threshold value, the color difference data W.sub.R and W.sub.B are set as zero. Then, the so-called block distortion can be prevented. The degree of the correction may depend on the amplitude of the chroma data W. On the other hand, DC coefficients of discrete cosine transform coefficients of adjacent blocks are compared with each other. When the DC coefficients are different from each other, block distortion occurs if they represent a same image. Then, if differences of DC coefficients of discrete cosine transform coefficients of adjacent blocks are small with each other, the DC coefficients are corrected to tend to have similar values.

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: In a video signal processing circuit, an adaptive signal compression is realized by correcting the color saturation by multiplication of color difference signals (R-Y, G-Y) by a same correction factor in such a way that color signal values (R, G, B) remain below their respective maximally allowed values without the luminance (Y) being limited as well. Preferably, the correction factor is obtained in dependence upon a non-linearly compressed luminance signal (Y').

Abstract: A method and circuit for correcting color errors in displaying a color video signal on the display of a color television receiver, the color television receiver having drive circuits for each of the colors red, green and blue, for forming respective color drive signals, in response to color signal components present in the color video signal, for the display, the method including setting up the color drive circuits of the color television receiver for conversion of the color signal components in the color video signal to the color drive signals to a ratio for producing a white color temperature higher than that specified in a television standard, detecting the presence and amount of color in the color video signal to be displayed on the display of the color television receiver, and reducing the color drive signals for at least two of the colors in dependence on the detected amount of color in the color video signal, whereby the resulting chromaticity of the displayed colors is the same as that when the color

Abstract: An inexpensive, yet robust color matcher is achieved by an apparatus which includes a compare device coupled to receive, as a first input, an input signal representing a combination of a luminance component Y and a chrominance component, and further coupled to receive as a second input, a threshold T, for comparing the input signal to the threshold T and outputting a color match signal if the input signal falls within a range defined by T and -T; and a threshold supply device coupled to the second input for supplying the threshold T, wherein the threshold T is a function of Y and at least two adjustable parameters.

Abstract: An image data processing system is disclosed which includes an image data receiving element, e.g., a CCD module, for receiving and converting a plurality of image data into electrical signals. The image data processing system further includes a color processing subsystem which includes the color separation unit, the RGB generation unit, the white balance control unit, the gamma correction unit, and the color space converter, for processing the electrical signals for generating color display output representing the color space of the image data. The image data processing system further includes a luminance processing units which includes two 1-H line memory units, the low pass filter, the edge enhancement unit, the summing circuit and the gamma correction unit, for filtering and processing the electrical signals for generating luminance output representing the luminance field of the image data.

Abstract: An input section receives an image signal including signals related to colors to output at least a luminance signal component of the image signal. A compressing section compresses the dynamic range of the luminance signal component from the input section. A setting section obtains a compression coefficient from a relationship between the luminance signal component whose dynamic range is compressed by the compressing section and the luminance signal component from the input section. An operating section executes an operation for compressing dynamic ranges of the signals related to colors included in the image signal in accordance with the compression coefficient obtained by the setting section. A correcting section substantially corrects the color saturation of the signals related to a color included in the image signal while preserving the luminance of the image signal such that the color saturation is more intensively suppressed as the luminance becomes lower.

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: A video circuit provided with corrective control data generator which generates respective control data for correcting and controlling the brightness and/or saturation of the picture displayed on a display unit in accordance with the average brightness level of the luminance signal separated from the video signal. The brightness and/or saturation of the picture are thus corrected and controlled on the basis of the corrective control data.

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: A level detection circuit includes a multiplier and an adder for computing the sums of square values of a burst signal. A maximum value holding circuit holds a maximum value of the sums of the squared values of the burst signal. A counter counts sampling clocks. A multiplier, an adder and a 1/2 processing circuit compute a half value of the sum of two consecutive count values, and a delay circuit, a latch circuit and a comparator generate a first one of the two consecutive count values as a level of the burst signal when an output of the 1/2 processing circuit becomes larger than the output of the maximum value holding circuit. The invention enables level detection by finding a square value using a small circuit.

Abstract: A system converts PAL and NTSC pixel clock signals to signals (in a studio, digital or square pixel format) at a sub-carrier frequency individual to the PAL and NTSC formats. The system includes a first register for providing a particular increase in the register count upon each occurrence of a pixel clock signal. Any remainder in the first register upon the production of the output signal is introduced to the register upon the occurrence of the next pixel clock signal. The particular increase in the first register count is controlled by a value in a second register, this value being adjustable dependent upon the system format and mode. A sequence of registers may be substituted for the first register with each register receiving an output from the previous register in the sequence. The system also converts signals representing the primary colors to luminance and chrominance signals.

Abstract: The present invention legalizes a video signal (e.g., 4:2:2 format) being processed in one format so that the video signal can be transformed to other formats (e.g., analog composite NTSC format). An editor can be notified of color legalities in a video signal. Further, each pixel of a video signal can be corrected to the nearest legal value by applying soft limits and gain slopes to a constant luminance color correction process. In accordance with the present invention, illegal colors of a video signal can be highlighted to provide an output drive for a video display which can be easily monitored by an editor. Alternate features of the present invention relate to error detecting and monitoring by assigning a specific, unique address to each video frame of a video signal. A further feature of the present invention relates to use of a pixel selecting means which receives 4:2:2 video data in either serial or parallel form.

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 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 raw correction signals are derived.

Abstract: A novel video signal correction system is disclosed, in which an average picture level detection circuit detects the average picture level (APL) of a luminance signal, and a coefficient calculation circuit calculates the amount of correction by the APL circuit. An adder adds an APL-corrected signal to a corrected luminance signal. A limiter circuit, on the other hand, limits the lower limit level of an input luminance signal. A divider circuit divides an output signal of the adder by an output signal of the limiter circuit, and the result is used to correct an input color signal. The color signal is thus capable of being corrected in accordance with the APL while at the same time preventing excessive correction of the color signal with a low brightness input.

Abstract: A circuit for regulating the color subcarrier amplitude in a video recorder used with a television receiver which employs overscanning of the electron beams for different modes of operation includes a regulating circuit for providing a regulating voltage representative of the amplitude of the color subcarrier. The regulating circuit includes a variable time constant circuit for switching from a short time constant during the overscanning to a long time constant immediately prior to ending the overscanning to change the regulating voltage in response to changes in the time constant. A variable amplifier is responsive to the regulating voltage to regulate the amplification of the color subcarrier in response to changes in the time constant.

Abstract: Disclosed herein is an apparatus for carrying out color correction on a video signal. The apparatus basically comprises a Y/C separating circuit for separating the video signal into a luminance signal and a color signal, a decoder for decomposing these signals into color separation signals, three three-row/three-column type color-correcting matrix circuits for electrically processing the color separation signals for color correction, an A/D converter circuit for converting the so-processed signals into digital signals, a frame memory for storing the digital signals therein as data, a correction circuit and a printer head. By using the apparatus referred to above, a user can emphatically perform correction on the hue, chroma and luminance of each of specific colors. Thus, the user can adjust the quality of an image with extreme ease.

Abstract: A method of and apparatus for regulating color in a color broadcasting receiver is disclosed and is composed of a tuner, a demodulator, and a burst level detector for detecting the color burst level of a video signal output from the demodulator and outputting the color burst level as a corresponding control voltage signal. A color controller is disclosed for controlling the color by emphasizing or attenuating the high band components of the video signal output from the demodulator in accordance with the control voltage level from the burst level detector, so that it is possible to receive video signals without much change in color regardless of the variation of the voltage standing wave ratio (VSWR) that varies according to changes in the connection between the broadcast antenna and RF cable.

Abstract: A method and an apparatus for correcting a color reproduction distortion for each of all the hues are provided. A predetermined demodulating axis of three demodulating axes SR, SG and SB for the three primary colors R, G and B, herein, the R-Y demodulating axis SR is formed by combining the two demodulating axes SR2 and SR3. The demodulating axis SR2 provides a different demodulating gain from the standard demodulating axis. The demodulating axis SR3 provides a different demodulating angle from the standard demodulating axis in addition to the different demodulating gain. Then, a smaller one of the signals demodulated by the demodulating axes SR2 and SR3 is selected. It means that the signal changing along the vector orbit E1 indicated by oblique lines is made to be a color difference signal R-Y.

Abstract: In a TV system which includes an autopix feedback loop limiting the range over which the contrast can be controlled, there is included means for generating a non-linear contrast control voltage as a function of customer control settings in order to extend the range over which the customer can control the contrast.

Abstract: Video systems generally include chroma processors. The chroma processor may be configured as a chroma keyer, a key signal generator or a color collector. The chroma processor includes dual input look-up tables which are loaded by a central processor. The dual input look-up tables may be read and written to simultaneously. The look-up tables are addressed by chrominance signals, luminance signals or key signals input into the chroma processor. The look-up tables provide an exceptionally fast apparatus and exceptionally flexible method of keying one or more simultaneous regions of the display based on one or more unique chroma/luma combinations, new key signals, chrominance signals, and luminance signals. The chroma processor receives color modification parameters from a software user interface. Preferably, the chroma processor utilizes Y luminance signals, and U and V chrominance signals.

Abstract: Simplified apparatus for controlling the phase and amplitude of the chroma subcarrier of a television signal is disclosed. The phase control includes compensation so that the color burst amplitude is stable as the phase is varied.

Abstract: A projection-type display apparatus having a lamp which emits a high intensity white light, two dichroic mirrors which filter out the three primary color beams from the white light and three liquid crystal panels which, respectively, modulate the color beams according to the three color image signals. Characteristics of the lamp and the dichroic mirrors are set so that the reproduction chromaticity range includes transmission chromaticity ranges of both the NTSC and HDTV systems. The image signals are supplied to two types of linear matrix circuit which are, respectively, suited for the NTSC and HDTV systems in order to correct color reproduction errors. The output of the linear matrix circuits are selected according to the system of the received television signal. In addition, a display white color temperature is set in the corrected image signals according to the system. Thus, the image signals are supplied to a display device such that the colors of the image can be accurately reproduced.

Abstract: An amplitude control device for controlling an amplitude of a data signal having an reference amplitude includes an A/D converter which converts the data signal to an n-bit digital signal, an extraction circuit for extracting the reference amplitude from the n-bit digital signal, a compactor for comparing the extracted reference amplitude with a predetermined amplitude to produce a first signal when the extracted reference amplitude is greater than the predetermined amplitude, and a second signal when the extracted reference amplitude is smaller than the predetermined amplitude. A counter counts up and down on receipt of the first signal and second signal, respectively, and produces an m-bit digital signal representing the counting result. A ROM stores a table in which the n-bit digital signal and the m-bit digital signal are used as an address for designating a value equal to the n-bit digital signal multiplied by a coefficient determined by the m-bit digital signal.

Abstract: Apparatus that is self-contained with video equipment, such as a video camera or video record/playback device, and which generates video signal adjustment data for use by video signal processing circuits that are included in such video equipment. An input video signal is coupled to luminance and/or chroma digital signal processing circuits which are supplied with luminance or chroma adjustment control data, respectively, for subjecting the input video signal to predetermined luminance or chroma adjustment operations, thereby producing adjusted digital luminance and chroma signals, respectively. At least one of the adjusted digital luminance and chroma signals is sampled at preselected times; and the sampled digital signals are used by an adjustment control data generator for generating the luminance and/or chroma adjustment control data that are supplied to the luminance and/or chroma digital signal processing circuits.