Abstract: Techniques relating to gamuts and gamut mapping are described. In one instance, a process identifies a gamut attribute and generates a gamut having the attribute.

Abstract: An image display device in which one dot is displayed using M (M is an integer larger than 3) sub-pixels having different colors and being disposed adjacent to each other in a vertical direction or horizontal direction, a ratio of a length of the sub-pixel of the one dot in a disposition direction to a length, in a direction orthogonal to the disposition direction being M:3, includes a resolution converter that converts the resolution in the disposition direction of the image data which defines an image to be displayed for every dot to 3/M; a color separating unit that separates the image data converted by the resolution converter into color components corresponding to the M sub-pixels for every dot; and a driving circuit that drives the sub-pixels so as to have a resolution defined by the image data separated by the color separating unit.

Abstract: A method for display compositing is disclosed. The method generally includes the steps of (A) generating a plurality of respective color values and a plurality of respective blending values for a plurality of graphics pixels to be blended with a display picture, (B) examining in a sequence a plurality of neighboring pixels of the graphics pixels adjoining a current pixel of the graphics pixels, the current pixel having a current color value of the respective color values and a current blending value of the respective blending values and (C) replacing the current color value with the respective color value for a particular pixel of the neighboring pixels where (i) the respective blending value for the particular pixel comprises one of a plurality of non-transparent values and (ii) the current blending value comprises one of at least one transparent value.

Abstract: In general, the present disclosure describes various techniques for creation of surfaces using a platform interface layer wherein such surfaces may have different format layouts for various different color spaces, such as the YCbCr color space. One example device includes a storage device configured to contain surface information and one or more processors configured to create a graphics surface within a color space using a platform interface layer. The platform interface layer lies between a client rendering application program interface (API) and an underlying native platform rendering API. The one or more processors are further configured to specify a format layout of data associated with the surface within the color space using the platform interface layer and to store the format layout within the storage device. The format layout indicates a layout of one or more color components of the data associated with the surface within the color space.

Abstract: A system for, and method of, color-compensating a video signal. In one embodiment, the system includes: (1) a first transformation circuit configured to receive and transform a gamma-encoded input video signal into a gamma-encoded RGB video signal R?G?B? and (2) a second transformation circuit coupled to the first transformation circuit and configured to receive and linearly transform the gamma-encoded RGB video signal R?G?B? into a chrominance-compensated, gamma-encoded rgb video signal r?g?b?.

Abstract: Performing color management of color image data using a device transform by generating an identifier key based on contents of a color measurement profile for a color device, the color measurement profile containing measurement data corresponding to the color device, determining if a device transform corresponding to the identifier key is present in a device transform cache disposed in a persistent memory, loading, in the case that it is determined that a device transform corresponding to the identifier key is present in the device transform cache, the device transform into a program-accessible transient memory, generating, in the case that it is determined that a device transform corresponding to the identifier key is not present in the device transform cache, a device transform based on the measurement data in the color measurement profile, and storing the generated device transform in the device transform cache in correspondence with the identifier key, and transforming the color image data based on the dev

Abstract: A method and apparatus for producing video signals comprises a receiver for receiving a video signal, a video pipeline for post-processing the received video signal, the video pipeline producing a post-processed video signal, and a video output module for converting the post-processed video signal, the video output module producing a formatted video signal. The video output module may further comprise an ancillary data injector, the injector inserting ancillary data into the post-processed video signal. Also, the video output system may further comprise a generator locking device or the video input module may include a generator locking device.

Abstract: An image compression device includes a floating-point texture-loading unit, a shader, a RGB to YCrCb compressor, and a parameter adjusting unit. The floating-point texture-loading unit receives raw image data that includes N number of RGB pixels. The shader receives the raw image data and shades the N number of RGB pixels. The RGB to YCrCb compressor receives the shaded image data and calculates the brightness/chroma value of each of the RGB pixels, wherein the chroma value of the RGB pixel having the smallest brightness value among all the RGB pixels is selected as a common chroma value for all the RGB pixels. The parameter adjusting unit receives and adjusts N number of brightness values of the RGB pixels and the common chroma value and stores them in a form of compressed image data into a memory.

Abstract: A first command is retrieved from a script containing one or more commands written for a first color space. The first command is associated with zero or more input buffers and zero or more output buffers. The first command has zero or more parameters. A behavior of the first command in the first color space and in a second color space is determined. The behavior comprises one of unique behavior, transparent behavior, and different behavior. The first command has the unique behavior when the first command only operates in the first color space. The first command has the transparent behavior when the first command generates similar results in the first color space and in the second color space. The first command has the different behavior when the first command generates different results in the first color space and in the second color space. Using the behavior of the first command, an operation associated with the first command is processed.

Abstract: Techniques and tools for representing pixel data in a video processing or capture system are described. Described techniques and tools provide efficient color representation for video processing and capture, and provide flexibility for representing colors using different bit precisions and memory layouts. Described techniques and tools include video formats that can be used, for example, in hardware or software for capture, processing, and display purposes. In one aspect, chroma and luma information for a pixel in a video image is represented in a 16-bit fixed-point block of data having an integer and fractional components. Data can be easily converted from one representation to another (e.g., between 16-bit and 10-bit representations). In other aspects, formats for representing 8-, 10- and 16-bit video image data (e.g., packed and hybrid planar formats), and codes for indicating the formats, are described.

Abstract: An image data processing method transforms a picture signal having a broad dynamic range to another picture signal having a narrow dynamic range. The picture signal having the narrow dynamic range is subjected to inverse transform to thereby output a recovered signal having the broad dynamic range. A difference between the original picture signal and the recovered signal, both having the broad dynamic range, is produced and then stored in a recording medium as difference data. A parameter for software processing to be executed for reproduction of the original picture signal later is also stored in the recording medium. In this way, the method can transform the original data with the broad dynamic range to the data of a standard file format with the narrow dynamic range, record the transformed data, and allow the original data to be recovered and effectively used later, as desired.

Abstract: The conversion of Mobile Display information used in a wide variety of Mobile Devices into Unified Image Formats is disclosed to enable viewing on a desktop computer system in addition to manual and automated testing of Mobile Content. In order to support the variety of Mobile Displays available, and to process the Mobile Display information in real-time, a configurable emulation system may be employed to model the Image Commands being used for each type of available Mobile Display. This emulation system can then provide a representative view of the image as it would be displayed on the Mobile Display, but in a format that can be utilized by other manual or automated systems.

Abstract: A multiple-pipeline system (300) includes a pool (330) of auxiliary function blocks (A-E 335) that are provided as required to select pipelines. Each pipeline (320) in the multiple-pipeline system (300) is configured to include a homogeneous set of core functions (F1-F6). A pool (330) of auxiliary functions (A-E 335) is provided for selective insertion of auxiliary functions (A-E 335) between core functions (F1-F6) of select pipelines. Each auxiliary function includes a multiplexer that allows it to be selectively coupled within each pipeline.

Abstract: The invention relates to a method of modifying the appearance attributes of digital images comprising: defining in a first channel of a color corrector a first set of appearance attribute corrections to be applied to the images; determining a first set of appearance attribute correction parameters corresponding to the first set of appearance attribute corrections; in the first channel of the color corrector defining at least one further set of appearance attribute corrections to be applied to the images; determining a set of appearance attribute correction parameters corresponding to the or each of the further sets of appearance attribute corrections; and combining each of the sets of appearance attribute correction parameters into a single set of appearance attribute correction parameters. The invention also relates to a method where the channel is implemented in software and to apparatus and software for carrying out the methods.

Abstract: A method for utilizing redundant color inks to improve image quality while minimizing any undesirable effects such as texture or graininess. The method comprises tessellating the available redundant color space as defined by the available redundant ink colorants into regions where the regions are arranged so as to minimize the range of luminance variation found within the regions. The result is perceived by the eye as less grainy in texture as well as much more pleasing to the eye.

Abstract: Systems and methods for processing linear colorspace data may be reused to process nonlinear colorspace data at a comparable performance level while maintaining the precision of the nonlinear colorspace data. Nonlinear colorspace data is converted to a compact floating point format in a linear colorspace used by conventional graphics processors. The compact floating point format includes an 8 bit explicit mantissa (without an implied leading one) and a 3 bit exponent to maintain the precision of the nonlinear colorspace data. The 8 bit mantissa may be processed by conventional texture filtering units designed to process 8 bit (fixed or floating point) color values. The 3 bit exponent may by processed by conventional texture filtering units designed to process floating point color values.

Abstract: A facial image photographed by a digital camera is downloaded to a PC. When a facial image correction program starts, a correction window and a correction item selection window open on a monitor. When a user opens the facial image in the correction window, a pixel extraction circuit extracts pixels representing a skin area, an eye area, a teeth area, and a hair area from the facial image. Correction items to be performed are determined in the correction item selection window. A cursor position detection circuit detects the position of a cursor in the correction window. When the cursor is in one of the areas, a facial image correction circuit judges whether the correction item corresponding to the area is selected. If the corresponding correction item is selected, the facial image correction circuit subjects a pixel pointed by the cursor to predetermined correction processing.

Abstract: In order to create a profile that associates lattice points defined in an equipment-dependent color space with lattice points defined in an equipment-independent color space, a reference profile that associates a plurality of lattice points in the equipment-dependent color space with lattice points in the equipment-independent color space is retrieved. A virtual force that acts on a focused lattice point in the equipment-independent color space is defined, and a position at which the focused lattice point is located in a steady-state in which the virtual force acts on the focused lattice point is calculated. The reference profile is referenced in order to retrieve a lattice point in the equipment-dependent color space associated with the position of the steady-state focused lattice point. A profile is created by associating the position of each steady-state focused lattice point with a lattice point in the equipment-dependent color space.

Abstract: A system and method of converting a red-green-blue (RGB) pixel to a red-green-blue-white (RGBW) pixel by using a W value extraction, the RGB-to-RGBW converting system including: a lookup table generator to generate an RGBW lookup table using one or more RGB lattice points; and an RGBW value computation unit to compute an RGBW value of an input pixel with respect to an RGB value of the input pixel based on the generated RGBW lookup table.

Abstract: Video conversion using a 3D graphics pipeline of a graphical processing unit (GPU) is disclosed. A plurality of video data formatted in a first video format is accessed from a memory unit. Moreover, the plurality of video data is converted from the first video format to a second video format using a 3D graphics pipeline of the GPU. The plurality of video data formatted in the second video format is sent to the memory unit. The 3D graphics pipeline applies a filtering technique. In an embodiment, the filtering technique is an interpolation technique.

Abstract: An image processing device has a storage unit, a read-out unit, a color information generating unit, a color information converting unit and a color replacing unit. The storage unit stores color information of spot colors. The read-out unit reads out the color information from the storage unit. The color information generating unit generates color information of an alternate color based on the color information of the spot color. The color information converting unit generates each of first and second color information, the first color information is generated by converting the color information of the color plate for which color replacement is instructed into the color information of the spot color, the second color information is generated by converting the color information of the color plate for which the color replacement is instructed into the color information of the alternate color. The color replacing unit generates new color information.

Abstract: A display apparatus includes a color image projection unit and a screen. The color image projection unit includes a converter which receives image signals of three primary colors, and converts the received image signals of three primary colors into image signals of four or more primary colors, and a color image projector which includes a plurality of image projection devices having respective primary colors, and which receives the image signals of four or more primary colors, and projects the received image signals of four or more primary colors onto the screen. The color image projector is capable of physically adjusting positions of the image signals of four or more primary colors, which are projected onto the screen such that the positions of the image signals are coincident with each other.

Abstract: A method for controlling a display and a display system using the same are disclosed. The method for controlling a display includes selecting one of a plurality of color space information stored at a monitor as color space information of a monitor, transmitting the selected color space information to a computer, selecting a profile corresponding to the transmitted color space information from among profiles stored at the computer, and applying the selected profile to an operating system (OS) of the computer. The method and system search a color profile according to a color space adjustment, and automatically register the searched color space to the OS. Therefore, errors occurred when the color is reproduced is minimized, and user convenience is maximized.

Abstract: The present invention provides a data processing apparatus and method for merging secure and non-secure data. The apparatus comprises at least one processor operable to execute a non-secure process to produce non-secure data to be included in an output data stream, and to execute a secure process to produce secure data to be included in the output data stream. A non-secure buffer is provided for receiving the non-secure data produced by the non-secure process, and in addition a secure buffer is provided for receiving the secure data produced by the secure process, the secure buffer not being accessible by the non-secure process. An output controller is then arranged to read the non-secure data from the non-secure buffer and the secure data from the secure buffer, and to merge the non-secure data and the secure data in order to produce a combined data stream, the output data stream then being derivable from the combined data stream.

Abstract: Systems and methods for processing signals are disclosed. The method may include, in a communication device that includes a chip operating to processing video signals, receiving video data from a camera. The received video data may include alternating YUV formatted video data and RGB formatted video data. The received video data may be separated into separate YUV images and separate RGB images. The separate YUV images may be transferred to a first device, and the separate RGB images may be transferred to a second device. The camera may be configured to generate the video data that includes alternating YUV formatted video data and RGB formatted video data. The separate YUV images may be DMA transferred to the first device. A DMA controller may be configured to alternately transfer the separate YUV images and separate RGB images. The alternate transfer via the DMA controller may occur without assistance from on-chip processor.

Abstract: A circuit and method for reducing artifacts in decoded color video and images are disclosed. The circuit includes a buffer for receiving an input pixel in a first color-space, and a detector for determining after transformation into a second color-space, if at least one component of the transformed pixel would fall outside a predetermined range. The determination may be made by comparing components of the input pixel, to corresponding ranges in the first color-space. Upon determining that at least one component of the transformed pixel would be outside a corresponding predetermined bound in the second color-space, the detector causes the circuit to output a pixel in the first color-space, with at least one predetermined component. The output of the circuit may subsequently be converted to the second color-space by an external color-space converter and displayed onto a color display. The method reduces visible artifacts caused by clipping during color-space conversion.

Abstract: A method to perform compositing of three-dimensional images includes, on a Central Processing Unit (CPU), automatically assembling a Graphics Processing Unit (GPU) program for each element of a plurality of image elements. The GPU program for each element is to apply at least one effect to the respective image element, and to composite the respective image element according to a compositing mode specific to the respective image element. The plurality of image elements, and the associated GPU programs, is communicated from the CPU to a GPU. The plurality of image elements may be subject to a two-pass sort operation prior to the automatic assembly of the GPU programs.

Abstract: A method for determining if a first pixel and a second pixel belong to a same surface includes: determining a spatial-difference value for the first pixel and the second pixel; determining one or more vision-difference values for the first pixel and the second pixel; determining, from the spatial-difference value, an initial same-surface probability value for if the first pixel and the second pixel belong to the same surface; determining, from the one or more vision-difference values, a first vision-difference probability value for if the first pixel and the second pixel belong to the same surface; determining, from the spatial-difference value and the one or more vision-difference values, a second vision-difference probability value; determining, from the initial same-surface probability value, the first vision-difference probability value and the second vision-difference probability value, an improved same-surface probability value for if the first pixel and the second pixel belong to the same surface.

Abstract: The present invention provides a method to reduce the power consumption. The method comprises these steps. First, the RGB gray levels of a pixel are decided. Then, the RGB gray level values are transformed to XYZ tristimulus values. The XYZ tristimulus values are transformed to L*a*b* values. Next, the L*?a*?b*? values are determined based on an acceptable color difference range. The color difference between the L*?a*?b*? and the L*a*b* is in the color difference range. Finally, the L*?a*?b*? values are transformed to X?Y?Z? values and the X?Y?Z? values are transformed to R?G?B? gray level values.

Abstract: A color conversion relation derivation method derives a color conversion relation between a first color space and a second color space. This method comprises an area-forming step that forms a plurality of areas filling the first color space; a partial function derivation step that derives, for each of the areas formed in the area forming step, a partial function representative of a color conversion between coordinates in the area and coordinates of the second color space using a set of an arbitrary sample point provided in the first color space and a point in the second color space, which is associated with the sample point; and a whole function derivation step that combines the partial functions for the respective areas derived by the partial function derivation step to derive a whole function representative of the color conversion relation through the first color space in its entirety.

Abstract: An image processing device includes a first conversion unit including a color conversion matrix circuit that inputs first image data and outputs second image data. The color conversion matrix circuit is able to arbitrarily set a conversion coefficient.

Abstract: In a method of managing color output by appearance intent a color display value is received. The color display value comprises at least one appearance intent tag and is associated with an item of graphic content. The color display value is converted into an intermediate color value such that an appearance intent specified by the appearance intent tag is preserved in the intermediate color value. The intermediate color value is converted into an output color display value recognizable by an output device, such that the appearance intent is preserved in the output color display value.

Abstract: An integrated circuit has a substantially non-customizable hardware portion and a mask-programmable logic portion. An image processing function common to many different makes and models of a type of electronic consumer device (for example, an image display device) is performed by the substantially non-customizable hardware portion. The substantially non-customizable hardware portion also outputs pixel data in both a first color space format and a second color space format. The mask-programmble logic portion can be mask-programmed for an individual manufacturer of electronic consumer devices such that the mask-programmable logic portion performs an additional special function specific to the electronic consumer devices of the individual manufacturer. Certain functions are better or more easily performed on pixel data in one color space format than another.

Abstract: An image generation system includes: a glare source drawing section which draws a glare source while referring to a Z value of an original image stored in a Z buffer to generate a first glare source image, and draws the glare source without referring to the Z value of the original image stored in the Z buffer to generate a second glare source image; a glare correction image generation section which performs image calculation processing including AND processing, of a first image which is an image obtained by subjecting the first glare source image to first blur processing and a second image which is one of an image obtained by subjecting the second glare source image to second blur processing and the second glare source image to generate a glare correction image; and a glare expression image generation section which generates a glare expression image based on the original image, the blurred image of the first glare source image, and the glare correction image.

Abstract: An improved color processing method for use in imaging systems transforms the input color image components into an output set of color image components, at least one of which is transformed using a non-linear transformation function.

Abstract: A method and apparatus is used for gamut mapping to a printer gamut that includes receiving a narrow gamut, a wide gamut, a printer gamut for printing on a printer and a predetermined mapping between the narrow and printer gamuts, identifying overlapping areas in the wide gamut, the narrow and printer gamuts, determining when the narrow gamut overlaps areas of the wide gamut, utilizing the narrow gamut values when the determination provides overlapping areas of the narrow gamut and the wide gamuts, selecting a wide gamut interpolation point corresponding to the surface of the printer gamut when narrow gamut areas do not overlap the wide gamut according to the determination, selecting a narrow gamut interpolation point by mapping the narrow gamut to the printer gamut and interpolating the narrow gamut interpolation point and the wide gamut interpolation point expanding the narrow gamut values into the printer gamut.

Abstract: A color conversion definition correction apparatus corrects a color conversion definition defining a relation between first color data representative of a color by coordinates on a first color space and second color data representative of a color by coordinates on a second color space in such a manner that a plurality of first color data has a one-to-one correspondence with a plurality of second color data. A smoothing processing is applied to the second color data. A color difference between the reference color set up and a color represented by the second color data subjected to the smoothing processing is determined. The second color data subjected to the smoothing processing is corrected, when the color difference is larger than the reference color difference, in such a manner that a color difference between a color represented by the second color data and the reference color is small.

Abstract: An imaging or other sensory reproduction system efficiently converts image or other sensory data between a perceptual color space (e.g., the sRGB color space) and a physical color space (unity gamma) or other perceptual/physical sensory models that are related by an expression involving a computationally expensive exponential function. The imaging system calculates exponential functions that can be composed from computationally inexpensive operations, such as square root, square, reciprocal, as well as multiplications and/or additions and subtractions. These computationally less expensive functions are then combined, such as in a weighted and/or offset mean, summation or difference to approximate the computationally expensive exponential function. The imaging system evaluates the expression using the approximation to efficiently yield the converted image data.

Abstract: A graphics processing graphics processing apparatus, which includes an RGB color space to a luminance color, blue color difference and red color difference (YCbCr) color space converter module configured to convert one or more pixel data from the RGB color space to the YCbCr color space using a set of approximated color space coefficients. The graphics processing apparatus further includes a hue and saturation control module coupled to the RGB to YCbCr color space converter module. The hue and saturation control module is configured to modify the hue and saturation of the pixel data in the YCbCr color space. The graphics processing apparatus further includes a YCbCr to RGB color space converter module configured to convert the pixel data from the YCbCr color space to the RGB color space.

Abstract: An image processing apparatus and information processing apparatus and method employs an output profile read-out unit that, according to a region designated by a preference selection unit, reads out one or more regional profiles from output profiles prepared for each such region. An output profile composing unit then combines the one or more output profiles based on a composition ratio input from the preference selection unit. The output profile is then input to a color matching processor for color matching.

Abstract: A method Abstract a histogram of HSV (Hue-Saturation-Value) colors from a color signal. The method includes receiving the color signal having a luminance component (Y) and chrominance components (CbCr). One section of a lookup table is selected according to the luminance component (Y) of the received color signal. The lookup table is divided into a plurality of sections each storing quantizing index values. Each section is divided by concentric circles corresponding to quantizing boundaries of the Saturation from a center, and divided by radial lines. Corresponding quantizing index values are selected according to the chrominance components (CbCr) of the received color signal in the selected section. The histogram index of the HSV colors is abstracted with reference to the selected section and the quantizing index values selected in the selected section.

Abstract: A system and method for color managing content elements on a display device are provided. The systems and methods for color managing content elements on a display device comprising using a set of color space characteristic values that describe a color space of the display device to create a profile having a multidimensional table encapsulating the display behavior as described by color space characteristic values for the display device.

Abstract: It used to be difficult to determine representative colors which allow color conversion with accuracy throughout color spaces without occurrences of local tone jump. An ink quantity lattice point smoothness evaluation function for evaluating the smoothness of the disposition of ink quantity lattice points whose components are the ink quantities of inks in various colors and a CMY lattice point smoothness evaluation function for evaluating the smoothness of the disposition of CMY lattice points defined by CMY color components are defined. The CMY lattice points and the ink quantity lattice points wherein the ink quantity lattice point smoothness evaluation function and the CMY lattice point smoothness evaluation function are separately minimized are taken as lattice points for correspondence definition data creation.

Abstract: A method is described which converts a three primary color input signal (Cx, Cy, Cz) into N drive signals (P1, . . . , PN) to drive N>3 primary colors of a multi-primary color display (3). The method determines (1) a valid range (VS) wherein the N drive signals (P1, . . . , PN) have valid values by performing the steps of (i) defining 3 functions representing 3 of the drive signals (P1, P2, P3) as a function of the remaining N?3 drive signal(s) (P4, . . . , PN), and (ii) calculating (1) a common range in a space formed by the N?3 drive signal(s) (P4, . . . , PN) wherein each one of the 3 functions has valid values. The method selects (2) a point from the common range to determine the N drive signals (P1, . . . , PN).

Abstract: A method and system for converting color image data (data outputting from element 202) from a, for example, three-dimensional color space format to a format usable by an n-primary display (206), wherein n is greater than or equal to 3. The system (converter 204) may define a two-dimensional sub-space having a plurality of two-dimensional positions, each position representing a set of n primary color values and a third, scaleable coordinate value for generating an n-primary display input signal (signal inputting toi display 206). Furthermore, the system may receive a three-dimensional color space input signal including out-of range pixel data not reproducible by a three-primary additive display, and may convert the data to side gamut color image pixel data suitable for driving the wide gamut color display.

Abstract: A system and method for determining whether a target display subsystem is compliant with a reference display subsystem is provided. A target display subsystem is selected for outputting image data. Drawing instructions are generated and applied to the target display subsystem. Image data generated by the target display subsystem, responsive to the applied drawing instructions, is periodically captured and recorded. The reference subsystem is selected, and the same drawing instructions are applied to the reference display subsystem. Image data generated by the reference display subsystem is periodically captured and recorded from the reference display subsystem. Thereafter, the captured image data from the target display subsystem and the reference display subsystem are compared to determine whether the target display subsystem is compliant with the reference display subsystem.

Abstract: A primary color dot gain correction unit corrects the spectral reflectance of each of a plurality of color agents on the basis of the dot quantity set for each color agent. An initial estimated value calculator estimates a mixed color by the KM theory using spectral reflectance data corrected by the primary color dot gain correction unit. An ink overlap correction coefficient storage unit stores correction coefficients, which are determined on the basis of errors between the actually measured values of spectral reflectance data of color patches obtained using the plurality of color agents, and estimated values estimated by the initial estimated value calculator based on the dot quantities of the respective color agents on the color patches.

Abstract: A compressed pixel level for a pixel in a frame of an image is compared with the (compressed) pixel level for the same pixel in a previous image frame. If the pixel level is unchanged, then the pixel is not moving. An uncompressed pixel level is then used for that pixel in the current image. If the pixel level is changed, then the pixel is moving, and a decompressed, boosted pixel level is used for that pixel in the current image.

Abstract: A method of redistributing an N-primary color input signal (IS) having a particular number?4 (N) of input components (I1, . . . , IN) into N-primary color output signal (OS) having the particular number (N) of output components (P1, . . . , PN) under a constraint (CON2). The method comprises defining (MPRC) three functions (F1, F2, F3) representing three (P1, P2, P3) of the output components (P1, . . . , PN) as a function of the remaining N-3 output components (P4, . . . , PN). Substituting (MPRC) the values of the input components (I1, . . . , IN) into the three functions (F1, F2, F3) to determine unknown coefficients (P1?, P2?, P3?) of the three functions (F1, F2, F3). And, determining (MPRC) optimal values of the output components (P1, . . . , PN) by applying the constraint (CON2) to the three functions (F1, F2, F3).

Abstract: Brightness of a plurality of pixels in a digital image is adjusted directly in a luminance-chrominance color space. Luminance and saturation are adjusted concurrently without changing hue of the pixels.