Abstract: A printing control system includes a plurality of printing units, an image source, and a system processing unit. The image source provides a print job comprising a plurality of images to the system processing unit. The system processing unit receives the plurality of images in the print job from the image source, and calculates an image histogram for each image in the print job. The system processing unit then determines the similarity of the images in the print job by comparing the calculated histograms. The system processing unit then classifies the images into classes based on the comparison, and sends the classes of images to the printing units.

Abstract: A linearization data structure is generated for a pen, in view of another pen, for conforming output intensities of the pen to output intensities of the other pen.

Abstract: A document-to-printer color gamut matching system enables comparison of at least two color maps in a manner that allows selection of the printer that will result in the best print output. Information related to the document to be printed and information describing the color gamut(s) that each available printer is capable of printing is compared. Each color gamut is evaluated to determine suitability for use with the document. The document-to-printer gamut matching system may provide the author of the document with a number of candidate printers best matched to the printing of the document depending on the rendering intent of the author; may select a printer based on a measurement of best fit; or may generate a custom color map to result in a color gamut that is satisfactory.

Abstract: A computer-readable medium of one embodiment of the invention is disclosed that has a data structure stored thereon to represent extended color gamut information for a pixel. The data structure has a number of data fields, where each data field is to store a number of bits representing a different color component of the pixel. The data structure also has at least one interpretation bit for each data field to indicate how the bits of the data field are to be interpreted in representing the different color component of the pixel.

Abstract: A color space conversion technique uses a set of control lines in a first color space. Each control line includes several control points having predetermined values in a second color space. A planar region is identified among the set of control lines in the first color space. The planar region contains a number of target points that are to be interpolated from the first color space to the second color space. The planar region is partitioned into at least a first area and a quadrangular area. Target points in the quadrangular area correspond to a different set of colorants from the second color space than target points in the first area. A quadrangular interpolation is applied to the target points in the quadrangular area to determine corresponding values in the second color space based at least in part on the predetermined values of control points bounding the quadrangular area.

Abstract: A method of forming images including obtaining image data defining an image portion and including data elements defining a first subset and a second subset of areas of the image portion having one or more lesser amounts and one or more greater amounts, respectively, of a colorant, and forming the image portion by placement of the colorant onto a medium during a set of overlapping passes so that the first subset of the areas is formed by at least one of (a) a subset of the overlapping passes and (b) a predefined subset of a plurality of structures available for placing the colorant.

Abstract: A generalized color calibration architecture and method are disclosed. A first interface receives raw measuring data of a sample from a measuring tool. The data has a color type, and the sample has one or more color targets. Each color target has an arrangement of one or more color patches. A second interface receives the color data type, one or more target identifiers specifying the targets, and a color patch order for each target identifier. The color patch order specifies the arrangement of the color patches of a corresponding color target. A color calibration manager performs the color calibration based on the raw measuring data, the color data type, the target identifiers, and the color patch order for each target identifier. The calibration yields or updates one or more color conversion tables for subsequent use with a device, such as a color printer, or another type of device.

Abstract: A method of mapping a color produced by an image device in a presentation color space to a destination color space including steps of receiving the color from the image device, determining if color is to be preserved, converting the color to the destination color space using a default profile if it is determined that color is to be preserved, and converting the color to the destination color space using a device-specific profile absent a determination that color is to be preserved.

Abstract: A method, includes depositing a first quantity of a first colorant corresponding to a first color value and a second quantity of a second colorant corresponding to a second color value on a region of media, determining a value related to a hue of the region, determining a difference between the value and a predetermined value. In addition, the method includes changing an association between the first color value and a first colorant quantity value, corresponding to the first quantity of the first colorant, according to the difference. An apparatus includes a spectral measurement device configured to generate output corresponding to a spectral content of light reflected from a region on media formed by depositing a first quantity of a first colorant and a second quantity of a second colorant onto the media. In addition, the apparatus includes a memory to store a plurality of color values and a corresponding plurality of first colorant quantity values.

Abstract: A color printing system and method for reducing bidirectional hue shift in inkjet printing. A set of data channels for the ink colors of the system is generated, including at least one print-direction-independent data channel, and at least one pair of print-direction-dependent data channels. A print controller receives the set of data channels for printing, and selects the print-direction-independent data channels, and one of each pair of print-direction-dependent data channels, to provide the data for printing in each opposite scanning direction of the print engine.

Abstract: Optimally determined halftoning algorithms are applied to tone values by selecting among combinations of at least two algorithms that best address the tradeoff between output quality and rendering performance. Input tone values are scrutinized and matched with the algorithm combination that processes the associated tone values in a manner that increases performance (including data compressibility) without sacrificing output quality. The selection process is computationally simple and fast. Reliability is ensured because the combinations of halftoning algorithms are tabulated as a result of analysis of test samples of the printed output.

Abstract: A color space conversion technique uses a set of control lines in a first color space. Each control line includes several control points having predetermined values in a second color space. A planar region is identified among the set of control lines in the first color space. The planar region contains a number of target points that are to be interpolated from the first color space to the second color space. The planar region is partitioned into at least a first area and a quadrangular area. Target points in the quadrangular area correspond to a different set of colorants from the second color space than target points in the first area. A quadrangular interpolation is applied to the target points in the quadrangular area to determine corresponding values in the second color space based at least in part on the predetermined values of control points bounding the quadrangular area.

Abstract: Optimally determined halftoning algorithms are applied to tone values by selecting among combinations of at least two algorithms that best address the tradeoff between output quality and rendering performance. Input tone values are scrutinized and matched with the algorithm combination that processes the associated tone values in a manner that increases performance (including data compressibility) without sacrificing output quality. The selection process is computationally simple and fast. Reliability is ensured because the combinations of halftoning algorithms are tabulated as a result of analysis of test samples of the printed output.

Abstract: Optimally determined halftoning algorithms are applied to tone values by selecting among combinations of at least two algorithms that best address the tradeoff between output quality and rendering performance. Input tone values are scrutinized and matched with the algorithm combination that processes the associated tone values in a manner that increases performance (including data compressibility) without sacrificing output quality. The selection process is computationally simple and fast. Reliability is ensured because the combinations of halftoning algorithms are tabulated as a result of analysis of test samples of the printed output.

Abstract: A method of mapping a color produced by an image device in a presentation color space to a destination color space including steps of receiving the color from the image device, determining if color is to be preserved, converting the color to the destination color space using a default profile if it is determined that color is to be preserved, and converting the color to the destination color space using a device-specific profile absent a determination that color is to be preserved.

Abstract: Color printheads in a color inkjet printer are in a fixed order in the scanning carriage, which causes the colors to be printed in a different order when the carriage is scanned in an opposite direction. The different print order may result in a perceptible change in hue between passes in bi-directional printing. Depleted shingle masks are substituted for the nominal ones, based on print direction, at the shingle masking stage, to compensate for print-direction-induced hue shift. A look-up table indexed by a composite color tone value providing a depletion probability and a halftoning error diffusion value are used in determining when depleted shingle masks are to be invoked.

Abstract: A method, includes depositing a first quantity of a first colorant corresponding to a first color value and a second quantity of a second colorant corresponding to a second color value on a region of media, determining a value related to a hue of the region, determining a difference between the value and a predetermined value. In addition the method includes changing an association between the first color value and a first colorant quantity value, corresponding to the first quantity of the first colorant, according to the difference. An apparatus includes a spectral measurement device configured to generate output corresponding to a spectral content of light reflected from a region on media formed by depositing a first quantity of a first colorant and a second quantity of a second colorant onto the media. In addition, the apparatus includes a memory to store a plurality of color values and a corresponding plurality of first colorant quantity values.

Abstract: A generalized color calibration architecture and method are disclosed. A first interface receives raw measuring data of a sample from a measuring tool. The data has a color type, and the sample has one or more color targets. Each color target has an arrangement of one or more color patches. A second interface receives the color data type, one or more target identifiers specifying the targets, and a color patch order for each target identifier. The color patch order specifies the arrangement of the color patches of a corresponding color target. A color calibration manager performs the color calibration based on the raw measuring data, the color data type, the target identifiers, and the color patch order for each target identifier. The calibration yields or updates one or more color conversion tables for subsequent use with a device, such as a color printer, or another type of device.

Abstract: A color printing system and method for reducing bidirectional hue shift in inkjet printing. A set of data channels for the ink colors of the system is generated, including at least one print-direction-independent data channel, and at least one pair of print-direction-dependent data channels. A print controller receives the set of data channels for printing, and selects the print-direction-independent data channels, and one of each pair of print-direction-dependent data channels, to provide the data for printing in each opposite scanning direction of the print engine.

Abstract: A document-to-printer color gamut matching system enables comparison of at least two color maps in a manner that allows selection of the printer that will result in the best print output. Information related to the document to be printed and information describing the color gamut(s) that each available printer is capable of printing is compared. Each color gamut is evaluated to determine suitability for use with the document. The document-to-printer gamut matching system may provide the author of the document with a number of candidate printers best matched to the printing of the document depending on the rendering intent of the author; may select a printer based on a measurement of best fit; or may generate a custom color map to result in a color gamut that is satisfactory.