Abstract: Systems and methods are operable to control operation of a portable media device based on machine readable information of a graphical artifact shown on a display concurrently with presentation of a video portion of a media content event. A portable media device, using a portable media device provisioned with an image capture device, captures at least one image that includes the display that is presenting the graphical artifact and the video portion of the media content event, identifies the graphical artifact in the captured at least one image, determines the machine readable data based on the identified graphical artifact, and operates the portable media device to perform at least one operation based on the determined machine readable data.

Abstract: A mobile device responds in real time to media content presented on a media device, such as a television. The mobile device captures temporal fragments of audio-video content on its microphone, camera, or both and generates corresponding audio-video query fingerprints. The query fingerprints are transmitted to a search server located remotely or used with a search function on the mobile device for content search and identification. Audio features are extracted and audio signal global onset detection is used for input audio frame alignment. Additional audio feature signatures are generated from local audio frame onsets, audio frame frequency domain entropy, and maximum change in the spectral coefficients. Video frames are analyzed to find a television screen in the frames, and a detected active television quadrilateral is used to generate video fingerprints to be combined with audio fingerprints for more reliable content identification.

Abstract: A first sequence of video fingerprints at a first image repetition rate is compared with a second sequence of video fingerprints at a second, different image repetition rate. A converted sequence of fingerprints is generated from the first or second sequence of fingerprints by forming a combination of the values of a number of neighbouring fingerprints. The combination is a weighted average based on the temporal location of the respective neighbouring fingerprints in the first sequence of fingerprints with respect to the fingerprint in the converted sequence. A correlation is then performed between the converted sequence of fingerprints and the other sequence of fingerprints.

Abstract: Systems, methods, and instrumentalities are disclosed for color space conversion. A video signal associated with a first color space may be received. The first color space may comprise a point. A partition of the first color space that includes the point may be determined. The partition may be associated with a first dimensionality. The point may be converted from the first color space to a second color space using a color space conversion model that corresponds with the partition. The color space conversion model may be associated with a second dimensionality. The second dimensionality may be less than the first dimensionality.

Abstract: Example methods and systems for displaying actionable elements over playing content, such as video content, are described. In some example embodiments, the methods and systems identify video content currently playing within a display environment provided by a playback device, and display an actionable element within the display environment provided by the playback device that is based on the identified video content and includes one or more user-selectable options to perform an action associated with the identified video content. Further, in some example embodiments, the methods and systems may perform an action (e.g., present supplemental content and/or information) in response to a selection of one or more of the user-selectable options.

Abstract: A media system, receives a received sequence of media content, for presentation at the media system and generates a comparison fingerprint of the received sequence of media content. The comparison fingerprint is for comparison with a plurality of reference fingerprints so as to identify the received sequence of media content. The media system sends a request for identification of additional content to a server system. The request is based at least in part on the comparison fingerprint. The media system receives a response to the request, including information enabling additional content to be selected for display at the media system based at least in part on the identification of the received sequence of media content, and presents a displayed sequence of media content that includes at least a portion of the received sequence of media content and at least a portion of the additional content.

Abstract: A display apparatus and a control method therefor are provided. Contents are displayed, a fingerprint is extracted from the displayed contents, it is determined whether there exists a prestored fingerprint that matches the extracted fingerprint, and when the prestored fingerprint that matches the extracted fingerprint exists, a fingerprint corresponding to the remaining sections of the contents is received from a server.

Abstract: Method for categorization of audio/video content, the method comprising the steps of: detecting a start and an end of at least one advertisements block present in said audio and/or video content; for each detected advertisements block: selectively collecting audio and/or video data frames, from said audio and/or video content, within specified time intervals prior to said detected advertisements block; for each time interval, computing a fingerprint; selectively collecting reference audio and/or video data frames, after said advertisements block, for comparison and computing a reference fingerprint for said reference audio and/or video data frames; comparing said reference fingerprint with at least one fingerprint collected prior to the start of said advertisements block in order to obtain a level of similarity between said fingerprints; based on the level of similarity, taking a decision whether to indicate a split point between content items present in said audio/video content.

Abstract: Particular embodiments detect a solid color frame, such as a black frame, that may include visible content other than the solid color in a portion of the frame. These frames may conventionally not be detected as a solid color frame because of the visible content in the portion of the frame. However, these solid color frames may be “functional” black or white frames, in that the solid color frames are performing the function of the solid color frame even though the frames include the visible content. The visible content may be content that may always be displayed on the screen even if the video content is transitioning to an advertisement. Particular embodiments use techniques to detect the functional solid color frames even when visible content appears in the solid color frames. Particular embodiments use color layout information and edge distribution information to detect solid color frames.

Abstract: An image processing apparatus for adjusting the luminance of a target pixel of an image is provided. The target pixel includes original pixel data and corresponds to a mask value. The image processing apparatus includes a luminance detection unit, a luminance compensation unit and a mapping unit. The luminance detection unit generates an original luminance value according to the original pixel data. The luminance compensation unit adjusts the original luminance value according to a non-linear function to generate a compensated luminance value. The mapping unit generates adjusted pixel data according to the compensated luminance value. The non-linear function at least includes a first monomial function, which has a base part associated with an inverse value of the original luminance value and an exponent part associated with the mask value.

Abstract: A system that adjusts chroma and luma values for a video signal is presented. During operation, the system receives a matrix of coefficients, which when applied to the chroma values and the luma values of a video signal produces substantially the same result as performing a sequence of discrete operations on the chroma values and the luma values, wherein the sequence of discrete operations includes one or more color-representation-conversion operations and one or more processing amplifier operations. For a given pixel of the video signal, the system performs a matrix-multiplication operation between a matrix representation of the chroma values and the luma values for the given pixel and the matrix of coefficients to produce a modified pixel.

Abstract: Detecting an object includes receiving depth data and infrared (IR) data from a depth sensor. A first background subtraction is performed on the IR data to create a first mask, and a second background subtraction is performed on the IR data to create a second mask. The first and second masks and the depth data are merged to create a third mask.

Abstract: Provided is an image processing device which enables image display that takes full advantage of a color reproduction performance of a panel without providing a viewer with a feeling of strangeness. An image processing device includes: a color gamut conversion processor configured to convert inputted data into RGB data according to a liquid crystal panel; a weighting factor calculator configured to calculate a weighting factor; a first post-color-gamut-conversion data weighting processor configured to perform weighting processing to the RGB data; an inputted data weighting processor configured to perform weighting processing to the inputted data; and an output adder configured to add data after the weighting processing to generate RGB data to be supplied to the liquid crystal panel.

Abstract: A screen time control device includes a source interface for receiving a video signal, a processor connected to the video source interface for overlaying the video signal with a translucent signal to produce an overlaid video signal, and a device interface connected to the processor for receiving the overlaid video signal and providing the overlaid video signal to the display device. The processor substitutes the translucent signal in the overlaid video signal with a parental signal, where the parental signal can be a substantially opaque overlay signal that masks an image on the screen of the display device to prohibit viewing of the screen, a textual message, or a combination of both.

Abstract: Some embodiments provide a program that provides a graphical user interface (GUI). The GUI includes a display area for displaying an image that includes several pixels. The GUI includes a selectable masking tool for displaying in the display area an adjustable closed curve to identify a region in the image to apply a color correction operation. The selectable masking tool includes a selectable control for modifying the adjustable closed curve through a range of elliptical shapes that ranges from a pure ellipse to an approximate rectangle. The GUI includes a selectable GUI item for applying the color correction operation based on the selectable masking tool.

Abstract: The present disclosure relates to a method and an apparatus for communication between a mobile phone and a TV set. The method comprises the following steps of: generating standard RGB signals by an LCD controller in a central processing unit (CPU) of the mobile phone; transmitting the RGB signals to an LCD of the mobile phone and a TV-OUT chip simultaneously; enabling the TV-OUT chip to receive and recognize the RGB signals through configuration of commands; carrying out video conversion on the RGB signals by the TV-OUT chip to output standard AV signals; and transmitting the AV signals to a display of the TV set via a dock. With this disclosure, information on the LCD screen of the mobile phone can be transmitted to the display of the TV set.

Abstract: A wide gamut RGB digital display, such as an LCD display, digital television, printer, or any other suitable display, includes wide color gamut configuration message control logic that is operative to indicate, to an image source provider, wide gamut RGB indication information and wide color gamut format definition information that indicates that wide gamut RGB color data is to be received by the wide gamut RGB digital display. The wide gamut configuration message control logic is also operatively responsive to wide gamut confirmation information that is received from the image source provider. The wide gamut RGB digital display also includes logic that is operative to display received wide gamut RGB color data that was received in response to the wide gamut RGB indication information and the wide color gamut format definition information.

Abstract: In one embodiment, an image decoding system for a YCbCr formatted signal includes a color space converter capable of representing an RGB image signal with one or two negative image signal components. The image decoding system further includes a degamma correction unit and an image signal formatter. An offset of the image black level from zero corresponding to the image signal offset produced by the color space converter is employed to perform degamma correction. In a further embodiment, gain, offset, and sign are removed from the image signal produced by the color space converter prior to degamma correction. The image signal formatter may utilize a one-dimensional and a three-dimensional lookup table to produce an image signal that may include secondary and white image components. The system advantageously accommodates decoding xvYCC-encoded image data in conventional as well as new hardware display system architectures.

Abstract: An image data processing includes: obtaining first image data; outputting the first image data to the image display devices; obtaining an attention area composed of one or more arbitrarily specified pixels from the first image outputted to the image display devices ; displaying a color chart whose hue and chroma are gradually changed toward around the color corresponding to the image data of the attention area; obtaining arbitrarily selected color information from the displayed color chart; obtaining a plurality of combinations of the attention area and the color information corresponding to the attention area and calculating a color parameter on the basis of the obtained plurality of combinations; converting the color of the obtained image data on the basis of the color parameter; and outputting the image data whose color is converted, to the image display devices as a second image.

Abstract: An image-signal processing unit comprising a first and second luminance calculation block, a correction-value calculation block, and a subtraction block, is provided. The first luminance calculation block calculates a first luminance corresponding to the sum of a plurality of primary color light components. Each of them is multiplied by a coefficient from a first coefficient combination. The second luminance calculation block calculates a second luminance corresponding to the sum of a plurality of the primary color light components. Each of them is multiplied by a coefficient from a second coefficient combination. The correction-value calculation block calculates a luminance correction value according to the second luminance if the first luminance is greater than a threshold value. The subtraction block calculates a corrected luminance by subtracting the luminance correction value from the first luminance.

Abstract: A color management unit is architected to achieve higher-quality appearance used in various video formats and to enable improvements in picture contrast and colorfulness. The color management unit comprises an optional input color space converter to convert the input digital video to a desired color space, an adaptive contrast enhancer to apply contrast improvement algorithms in response to different scenes in either manual or automatic modes, intelligent color remapping for enhancing selected colors, sRGB compliance to produce a video display that is uniform over different monitors, global color and brightness controls to combine global processing and color conversion, gamut compression to maintain pixel validity in color space conversion, and gamma correction to compensate for nonlinear characteristics of an output display.

Abstract: A color management unit is architected to achieve higher-quality appearance used in various video formats and to enable improvements in picture contrast and colorfulness. The color management unit comprises an optional input color space converter to convert the input digital video to a desired color space, an adaptive contrast enhancer to apply contrast improvement algorithms in response to different scenes in either manual or automatic modes, intelligent color remapping for enhancing selected colors, sRGB compliance to produce a video display that is uniform over different monitors, global color and brightness controls to combine global processing and color conversion, gamut compression to maintain pixel validity in color space conversion, and gamma correction to compensate for nonlinear characteristics of an output display.

Abstract: A method and system marks a scene and images acquired of the scene with tags. A set of tags is projected into a scene while modulating an intensity of each tag according to a unique temporally varying code. Each tag is projected as an infrared signal at a known location in the scene. Sequences of infrared and color images are acquired of the scene while performing the projecting and the modulating. A subset of the tags is detected in the sequence of infrared images. Then, the sequence of color image is displayed while marking a location of each detected tag in the displayed sequence of color images, in which the marked location of the detected tag corresponds to the known location of the tag in the scene.

Abstract: An apparatus for converting input image signals into image signals that can be displayed in an image display device. The image display device includes a color space converter converting color components of the input image signals and color components that can be displayed in the image display device into color space, a hue control variable calculator comparing a converted color gamut with each other to calculate a hue control variable, and a hue controller controlling hues of the input image signals using the hue control variable.

Abstract: A control of gobos defend by records in the gobo. The gobos are formed by menued shapes.

Abstract: In a method for reversibly transforming a data format, a forward transformation and a backward transformation are reciprocally conducted for data between unit systems having different resolution levels, and the forward transformation and the backward transformation, a first unit system having a lower resolution level is used as a common unit system, and a reversible data conversion is conducted by an integer operation for data in the first unit system having the lower resolution level and data in a second unit system having a higher resolution level higher than the first unit system.

Abstract: A mask circuit masks a digital video signal so that a video signal of an analog video signal is not outputted for a predetermined period after the start of output of a horizontal synchronizing signal of the analog video signal. A period of masking the digital video signal by the mask circuit is set in a control register, and the control register transmits the masking period to the mask circuit. A digital video signal to analog video signal converting unit converts the digital video signal masked and outputted from the mask circuit into an analog video signal. Thus, by setting in the control register the period of masking the digital video signal until the video signal of the analog video signal is stabilized, a digital video encoder can output a stable video signal.

Abstract: A multiple-format video encoder stores values of the sine and cosine functions in a ROM. According to the externally specified video format, an address calculating circuit calculates the addresses at which to access the ROM. In the multiple-format video encoder, a luminance/color-difference signal generating circuit generates color-difference signals B-Y and R-Y from digital RGB signals. A first multiplying circuit multiplies the color-difference signal B-Y by the values of the sine function stored in the ROM at the addresses specified by the address calculating circuit and multiplies the color-difference signal R-Y by the values of the cosine function stored at the same addresses.

Abstract: A method is provided for automatically adjusting the color of a digital image. In one aspect, an strength offset is determined to automatically remove gray from a distorted image. In an other aspect applied independently or after gray removal, scaling factors are automatically determined to adjust the image to conform to empirically determined optimal brightening of the image. Using a determination of color dot maximums and a function which ensures constraint within the dynamic range, scaling factors are established which correspond to the strength values of each dot maximum and which are applied to each of the dot's R,G and B to maintain ratios therebetween and thus maintain the true color. The function for establishing the scaling factors is interpolated from a nominal function and a target average strength for the image.

Abstract: A method and system for creating authentication signatures for digital images and video frames is provided. The method and system involves partitioning the image into multiple blocks, comparing characteristics from each block and generating data bits based on the comparison. Each block is then broken up into additional blocks and those blocks are compared to create additional signature bits which are combined with the signature sets from the first set of blocks. Each of these new smaller blocks can be further broken up and the procedure can be repeated to provide an authentication signature of desired length.

Abstract: A method of and an apparatus for enhancing digital image quality. Input color data are transformed to obtain brightness data and chrominance data. The transformed brightness data is compared with predetermined brightness levels X1 and X2 on a pixel by pixel basis and the brightness data of each concerned pixel is reset or output without change according to the comparison. The comparison identifies the concerned pixel as belonging to one of a dark area and a light area requiring contrast enhancement and the brightness level of the concerned pixel is adjusted to provide the enhanced contrast. The obtained chrominance data and the reset brightness data are inversely transformed into corresponding color data. The predetermined brightness levels X1 and X2 are adaptively recomputed after a last pixel in a concerned line is considered for contrast enhancement.

Abstract: A mask circuit masks a digital video signal so that a video signal of an analog video signal is not outputted for a predetermined period after a start of output of a horizontal synchronizing signal of the analog video signal. A period of masking the digital video signal by the mask circuit is set in a control register, and the control register transmits the masking period to the mask circuit. A digital video signal to analog video signal converting unit converts the digital video signal masked and outputted from the mask circuit into an analog video signal. Thus, by setting in the control register the period of masking the digital video signal until the video signal of the analog video signal is stabilized, a digital video encoder can output a stable video signal.

Abstract: An apparatus for processing image data including three complementary color components representing the three primary colors includes a distribution circuit for distributing the image data into first to third complementary color components. A multiplication circuit generates first to third products by multiplying the first and second complementary color components, the first and third complementary color components, and the second and third complementary color components. A square root circuit then calculates the square root of each of the three products. The calculated square roots represent the three primary colors.

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: 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: 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: An objectionable outlining effect, seen as dark edges and white edges outlining everything in a scene, is eliminated by clipping or limiting the spikes generated by excessive enhancement. Specifically, a method is used for improving the quality of an enhanced video image, while simultaneously maintaining or improving image sharpness, by clipping the RGB levels of the enhanced video image, at the points of enhancement, to upper and lower level bounds representing the signal levels of the video signal prior to its enhancement.

Abstract: A simplified Y/C separation circuit in which, a plurality of luminance signals are calculated for the subject pixel based on an NTSC signal of the subject pixel and NTSC signals of pixels that are close to the subject pixel spatially or temporally. Correlations between the plurality of luminance signals are obtained in a difference circuit and a comparison circuit. In a classification circuit, classification is performed, that is, the subject pixel is classified as belonging to a certain class, based on the correlations between the plurality of luminance signals. Prediction coefficients corresponding to the class of the subject pixel are read out from a prediction coefficients memory section. The RGB luminance signals of the subject pixel are then determined by calculating prescribed linear first-order formulae.

Abstract: A method and system for matching color displayed by source and destination display devices and particularly for providing color matching between a computer monitor and an ink printer. The technique of the present invention initially determines the combination and color value ratios of single destination color components that will cause the destination device to display a color that essentially matches each of fully saturated single and dual colors of a source display device. These combinations of single destination color components and their corresponding color value ratios determine the best available blends of destination device color components for printing source device colors. A color matching algorithm is employed to derive the color value ratios—one for each of the single destination color components.

Abstract: To obtain a clear-cut picture image by correcting a contour of a video signal of a natural picture image and the like from a computer. Video signals of, for example, three primary colors (R, G, B), including a natural picture image and the like produced by, for example, a computer from input terminals 1 are supplied to a mixing circuit (2) and mixed at a ratio of, for example, 0.6G+0.3R+0.1B to produce a signal corresponding to a luminance (Y). This signal is supplied to differentiation circuits 3A and 3B having different time constants each other and predetermined high frequency components are extracted therefrom, respectively, and these output signals are selected by a switch (4), and then supplied to an amplifying circuit 5. The gain of the amplifying circuit 5 is arbitrarily controlled by a signal from a control terminal (6).

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 method of providing conversion from YUV signals to RGB signals includes the steps of determining a correspondence value between each of the Y. U, and V pixel values and the corresponding one of the R, G, and B pixel values. Three tables are generated; a Y table, a U table and a V table. During operation, each table may then be easily accessed by indexing the table with the respective Y, U or V input, to provide R,G,B data. The method may be used in a 64 bit embodiment using two registers or one register. Alternatively, the method may be used in a 32 bit embodiment. The conversion method can easily be augmented to provide color adjustment during conversion without any added complexity.

Abstract: A luminance signal generation circuit with single clamp generates a separate luminance signal Y by combining RGB input signals in a weighted manner within a Y-Matrix circuit. During a burst period the single clamping circuit is enabled. When enabled, the single clamping circuit compares the separate luminance signal Y to a constant reference voltage signal. A difference signal, representing the difference between the separate luminance signal Y and the constant reference voltage signal, is used to adjust a blanking level of the RGB input signals until the blanking level of the separate luminance signal Y is equal to the constant reference voltage signal. During the non-burst periods the single clamping circuit is disabled and the Y-Matrix circuit combines the RGB input signals into the separate luminance signal Y. Preferably, the single clamping circuit sets the blank level of the separate luminance signal Y to a level equal to two volts.

Abstract: A color feature extracting apparatus is provided, which can easily transform a RGB color space into a color space close to the human sense and execute color classification and color region distinction of a digital image in the transformed color space. RGB values of each pixel of a digital image are transformed into HLS values by a color space transforming section. A hue value and a luminosity value of the HLS values are corrected by a hue correcting section and a luminosity correcting section, respectively, so that a region between a green color and a yellow color in a direction of hue and a region between the green color and a light blue color in the direction of hue are narrowed and a region between a red color and the yellow color in the direction of hue is widened in a color space represented by the HLS values. Then, the color features of the digital image are extracted by a color feature extracting section on the basis of the corrected hue value and luminosity value.

Abstract: In a method and apparatus for converting digitized luminance-chrominance color space signals to digitized RGB color space signals, starting chrominance-in-color terms of a standard set of conversion equations are expanded into linear combinations of expanded chrominance-in-color terms that involve only predictive and compensative coefficients. Predictive and compensative code generators respectively generate predictive and compensative transformation codes that correspond to a first one of the chrominance color space signals during a first timing phase and that correspond to a second one of the chrominance color space signals during a second timing phase. The predictive and compensative transformation codes from the predictive and compensative code generators are transformation values for the expanded chrominance-in-color terms and are linearly combined to obtain transformation values for the starting chrominance-in-color terms.

Abstract: A method and system for matching color displayed by source and destination display devices and particularly for providing color matching between a computer monitor and an ink printer. The technique of the present invention initially determines the combination and color value ratios of single destination color components that will cause the destination device to display a color that essentially matches each of fully saturated single and dual colors of a source display device. These combinations of single destination color components and their corresponding color value ratios determine the best available blends of destination device color components for printing source device colors. A color matching algorithm is employed to derive the color value ratios--one for each of the single destination color components.

Abstract: In a process for color transformation from the input-side primaries (R, G, B) to image-side primaries (R", G", B") with a greater color stimulus specification region than that given by the input-side primaries (R, G, B), a color transformation is carried out by converting the components of a color vector from the input-side primaries to fictitious primaries (R', G', B') so that the color stimulus specification of the color vector is changed, and transforming of the converted components of the color vector from the fictitious primaries (R', G', B') to the image-side primaries (R", G", B") for generating image-side components of the color vector, wherein the image-side color stimulus specifications produced in this way have the same hue and the same saturation as the transformed color stimulus specification in the fictitious primary system (R', G', B').

Abstract: A color correction device, for strengthening or weakening a specific color according to the selection of a user, is provided. In a color correction device, the area of an input color signal is determined according to chrominance axes, coefficients of a corresponding coordinate of the chrominance axes are read from a storage memory, and a matrix operation is performed on the input color signal before it is output. An index table divides the area defined by chrominance axes on the basis of r, g, and b signals. A storage memory contains coefficients corresponding to the respective coordinate positions for correcting the color signal to represent colors similarly to the original color of the subject. A specific color may be strengthened or weakened based on the selection of a user, due to the addition of a second storage memory which contains, coefficient tables for designating areas according to the chrominance axes corresponding to a color to be strengthened or weakened.

Abstract: Conversion of YUV-format data into RGB-format data is consecutively carried out through pipeline processing in two stages, namely, primary and secondary conversion which are derived from only the common expressions of theoretical conversion equations. The secondary conversion is executed by a circuit subsequent to ROMs 51a to 51c. Of the secondary conversion operation, the conversion of a G component requires complicated calculation. Therefore, analogous calculation is carried out to convert the G component.

Abstract: In a color correction apparatus for a color display device using 2-dimensional (2-D) chromaticity partitioning, a chromaticity plane is unevenly partitioned such that partitioned areas adjacent to each vertex of the chromaticity plane have larger areas. An area determining unit projects an input 3-D color signal onto the 2-D chromaticity plane, and outputs an index representing the location of the input color signal in the 2-D chromaticity plane. A first memory stores index values of the unevenly partitioned areas of the chromaticity plane, and outputs an index value corresponding to the index. A second memory stores transform coefficients of a matrix defining an input-output relationship of the color signal and outputs a predetermined number of transform coefficients stored in an address designated by the index value output by the first memory.