Eastman-kodak Company

Kodak Polychrome Graphics, Gmbh

Minnesota Mining and Manufacturing Company

Imation Corporation

William A Rozzi

Timothy A Fischer

Christopher J Edge

Hahn Chung

Gregory L Zwadlo

Peter Stolt

A method for adjusting a color in a color space comprises adjusting the color along a gradient path to a point in or on a color gamut. The gradient path is determined from a potential field derived from the color gamut consisting of gamut points in the color space. The potential field can be derived from one or more points in the color gamut and different functions may be used to determine the potentials due to different points in the gamut. The potential at a point in the color space due to the gamut point can be a function, including an inverse power, of distance of the point in the color space from the gamut point. The gradient path can be determined from the gradient of the potential field by quadric error-based surface simplification of a surface mesh representing a surface of the gamut.

Potential field-based gamut mapping

An improved relief printing plate and method for producing said plate is disclosed. Substantially all sizes of relief features resolve a fixed pattern which improves print quality. The pattern is applied to image areas in halftone data used to produce an image mask that is subsequently used to convert a plate precursor into a relief plate. The accuracy, ink density and tonal response of printed images corresponding to relief features that include the pattern are comparable or better than relief features produced without the pattern.

Enhanced relief printing plate

Modification of color values in a page description file can be carried out by converting implicit color commands within the page description file to explicit color commands. The color values specified by the explicit color commands within the page description file then are adjusted to calibrate an output device for enhanced color fidelity. Implicit color commands specify color values indirectly, for example, by defining color as a function of other graphic information and color reference values. Consequently, color modification prior to RIP conversion generally is difficult. Conversion and modification of explicit color values provides a higher degree of color conversion accuracy without the need for RIP conversion of the page description file.

Modification of color values in page description files

A color imaging technique includes setting a target value in a device-independent first color space and mapping the target value to a substantially complete point set in a second color space. The point set may include a plurality of points, each of which define substantially the same calorimetric value via a unique combination of colorants. After mapping the target value to a substantially complete point set, a point may be chosen. Moreover, after choosing a point in the point set, device-dependent colorant values defined by the point may be determined. In this manner, the invention may provide control over the colorants that are used to image a particular color.

Gamut-preserving color imaging

A color mapping method is used in transforming colors between color imaging systems. The method includes using forward transformation profiles that characterize the color imaging systems to generate respective sets of device-independent color values for the color imaging systems. Color conversions are calculated by recursively reducing differences between the respective sets of device-independent color values. Based on these color conversions, a color map is constructed that describes a relationship between the color imaging systems.

Arrangement for mapping colors between imaging systems and method thereof

Techniques are described for preparing halftone bitmap images for printing on inkjet printers. The techniques may involve exclusive use of low-density inks to reproduce highlight colors and means for reducing the amount of ink applied to the page within 'solid' areas while maintaining complete coverage of these areas. The techniques may rely on the high addressability and larger ink palette of recent inkjet printers. For example, some inkjet printers offer seven ink channels: low and high density inks for the cyan, magenta, and black channels, and a single high-density yellow ink. In one embodiment, halftone dots within a bitmap image are separated into perimeter data and core data. The perimeter data is then associated with a low-density ink channel and the core data is associated with a high-density ink channel.

Halftone proofing with inkjet printers

A color imaging technique includes setting a target value in a device-independent first color space and mapping the target value to a substantially complete point set in a second color space. The point set may include a plurality of points, each of which define substantially the same colorimetric value via a unique combination of colorants. After mapping the target value to a substantially complete point set, a point may be chosen. Moreover, after choosing a point in the point set, device-dependent colorant values defined by the point may be determined. In this manner, the invention may provide control over the colorants that are used to image a particular color.

A method of characterizing a color imaging system is provided. The method comprises obtaining first data indicative of output of the color imaging system. The first data is processed, to yield second data, according to a color appearance model that varies in accordance with neutrality of colors indicated by the first data. Other methods are provided as well as systems and computer program products for characterizing color imaging systems and devices and for producing colors.

Color processing

A color mapping method is used in transforming colors between color imaging systems. The method includes using forward transformation profiles that characterize the color imaging systems to generate respective sets of device-independent color values for the color imaging systems. Color conversions are calculated by reducing differences between the respective sets of device-independent color values. Based on these color conversions, a color map is constructed that describes a relationship between the color imaging systems.

Arrangement for mapping colors between imaging systems and method therefor

A system and method for multi-dimensional color transformation apply constraints to the transformation function to preserve the presence or absence of particular color information while achieving high accuracy color match. With a constrained multi-dimensional color transformation (CMT), a destination device, such as a color proofer, can provide an accurate color match relative to a source or 'target' device, such as a printing press, and preserve dot integrity. In particular, the constraints can preserve selected color information that is present in an image produced by the source device, and prevent addition of other selected color information that would not be present in the source device image. In a halftone imaging device, the constraints prevent the removal or addition of dots from and to the image produced by destination device.

Constrained multi-dimensional color transformation

The invention provides a color processing method comprising determining whether a desired mapping between a first arrangement, including a first color device, and a second arrangement, including a second color device, exists, and automatically producing a mapping between the first arrangement and the second arrangement in the absence of such a desired mapping.

The invention provides techniques for thinning halftone dots in a halftone dot bit map. A bit map filter may be used to thin the dots. For example, a target glyph may passed over the bit map. If any subsets of bits within the bit map match the target glyph, the subsets of bits can be replaced with bits defined by a thinned glyph. In this manner, the ink of a halftone print can be reduced in a manner that enhances the visual appearance of the print.

Halftone dot thinning

In one embodiment, a display device includes an integrated color matching processor that processes color data to facilitate accurate color rendering on the display device. The integrated color matching processor can be internal to the display device or external to the display device. Either way the processor may receive color input, process the color input, and output altered color image data to the display.

Color display device with integrated color matching processor

A method for producing halftone dot patterns involves generation of a halftone dot pattern one color channel as a function of the halftone dot pattern generated for another color channel. Placement of dots for one color channel in view of dot placement of one or more other color channels can enhance image quality, promoting improved spacing of dots among the halftone dot patterns generated for the overprinted color channels. Dot placement for a color channel may depend on the number of dots placed for color channels that precede it in the halftoning process. With improved dot spacing in view of inter-channel effects, an inter-channel dot placement method can reduce the incidence of mottle and other image artifacts, improving the visual appearance of the integrated image. A master threshold array may be used to produce halftone dot patterns for all color channels, but applied, in effect, on a shifted basis to promote improved inter-channel dot spacing.

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Stillwater, MN, United States of America

William A Rozzi