Abstract:
The present invention provides for determining a gamut boundary description for a color device, the color device being characterized at least by a destination transform which converts colors from a device-independent color space to a device-dependent color space and which reports out-of-gamut colors. A set of sample values is determined in the device-independent color space. For each of the sample values within the set of sample values, the destination transform is applied to the sample value, and in a case where the sample value is in gamut, the sample value is included within a set of gamut boundary values. The gamut boundary description is determined by forming a set of polygonal surfaces based on the set of gamut boundary values. Accordingly, a gamut boundary description is determined without necessarily having to sample additional color values as the number of colorant channels for the color device increases.
Abstract:
An overall color transformation is constructed from multiple ones of individual color transformation steps, the overall color transformation used by a color management system to transform colors from one color space to another. A sequence of sequential add operations is executed, each add operation adding a single one of the individual transformation steps to an intermediate transformation constructed from preceding add operations, and for each add operation returning at least one value which characterizes the add operation. The sequence of subsequent add operations is altered based on preceding ones the returned values.
Abstract:
Managing color data to transform source color image data from a source device into destination color image data for rendering by a destination device, including accessing a source color data file corresponding to the source device, the source color data file containing source device color characteristic data, constructing a source color transform based on the source device color characteristic data contained in the source color data file, and applying the source color transform to the source color image data to transform the source color image data from a source device color space into interim color image data in an interim color space.
Abstract:
A method and apparatus for generating transform-based color profiles by a measurement-based Color Management System (CMS). The measurement-based CMS generates the transform-based profile wherein the measurement-based color system is parameterized by color data and procedures. The CMS may use a reference Profile Connection Space (PCS) loaded from a measurement profile, thus enabling user configuration of the generation process. The reference PCS may also be set to include a gamut that is appropriate for an eventual color-output device. In addition, a Gamut Mapping Model (GMM) used in the generation process is user-selectable as well as a Device Model (DM). The DM may also be supplied as a pluggable module. The CMS also features user-selectable mapping from an International Color Consortium (ICC) intent to a PCS profile and to a DM. The features of the CMS may be used in an application, stand-alone profiling tool or in an operating system utility.
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 device transform loaded in the program-accessible transient memory.
Abstract:
A color descriptor data structure corresponding to a color device, the color descriptor data structure including a reference color data set corresponding to a reference boundary descriptor representing reference colors of the color device based on measured colors from a reference color target, a plausible color data set corresponding to a plausible boundary descriptor representing plausible colors of the color device which are observable, which encompass at least the reference colors of the reference boundary descriptor, and which include a whitest-white color and a blackest-black color, and a neutral color data set corresponding to neutral colors of the color device, the neutral colors extending in range from the whitest-white color to the blackest-black color.
Abstract:
A color management system that transforms input image data from an input colorant space to an output colorant space using input and output device appearance transforms and a customizable gamut mapping algorithm. The gamut mapping algorithm is customizable based on the color management session in question, and in particular may be customizable based on the content of the image data, based on a comparison between input device appearance transforms and output device appearance transforms, or based on viewing conditions, output conditions or print media involved. According to the invention, the customizable gamut mapping algorithm is customized based on the current color management session, and the customized gamut mapping algorithm is composited with the input device appearance transform and/or the output device appearance transform thereby yielding one or more transformations that can be applied to the input image data more efficiently than if the transformations (including the gamut mapping algorithm) were applied individually.
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 device transform loaded in the program-accessible transient memory.
Abstract:
The present invention relates to a color management method for controlling the amount of black ink used by a destination device with a black channel when converting colors from one of a plurality of source device color spaces to destination device color space. This conversion is accomplished by obtaining a black weight of a source pixel in the source device color space, transforming the source pixel into a color in color appearance space, and calculating destination values based on the color in color appearance space and the obtained black weight. In the case that the source device color space does not include a black channel, the black weight is obtained from a color purity of the source pixel. In the case that the source device color space is a device space including a K channel, the black weight is obtained from the K channel.
Abstract:
Mapping color image data from a source color gamut to a destination color gamut, wherein the mapping includes identifying source color boundary regions in the source color gamut based on descriptor data provided in a source color descriptor data structure, and determining a position of each identified source color boundary region, identifying destination color boundary regions in the destination color gamut based on descriptor data provided in a destination color descriptor data structure, and determining a position of each identified destination color boundary region, and mapping the color image data from the identified source color boundary regions to the identified destination color boundary regions based on a correspondence between the determined positions of the identified source color boundary regions and the determined positions of the identified destination color boundary regions.