Eastman-kodak Company

John R D'Errico

Gustav J Braun

Kevin Edward Spaulding

Geoffrey John Woolfe

Robert E Cookingham

Douglas W Couwenhoven

Karin Topfer

Paula J Alessi

James R Niederbaumer

David W Bishop

Jonathan B Phillips

Brian T Pridham

Donald M Reiman

A method for determining a blended color transform for use in producing printed colors on a color printer having at least four device color channels, comprising: forming first and second color transforms, wherein the first color transform produces printed colors that have a reduced sensitivity to color printer process variations in at least a first region of color space that includes a near-neutral color region, and wherein the second color transform produces printed colors that have a reduced image noise visibility in at least a second region of color space; defining a blending function which computes weighting values for the first and second color transforms as a function of input color values; and using a processor to determine the blended color transform by blending the first color transform and the second color transform, responsive to the blending function.

Color transform insensitive to process variability

A method for determining colorant control values for a color imaging device having four or more colorants is disclosed. The method includes defining a color mapping for a set of paths through a three-channel color space, defining a color mapping function for the three-channel color space relating the three-channel color space values to colorant control values for the four or more colorants of the color imaging device by interpolating between the color mapping defined for the set of paths, forming a forward three-channel color model relating the three-channel color space values to device-independent color values, inverting the forward three-channel color model to determine an inverse three-channel color model relating the device-independent color values to the three-channel color space values, and combining the inverse three-channel color model and the color mapping function to determine an inverse device color model.

Colorant control values for color printing devices

A method for determining a set of n-dimensional colorant control signals that map to a point P in an m-dimensional color space where n&#x3e;m, including determining a forward device model that maps n-dimensional colorant control signals to m-dimensional color space signals; determining a set of n-dimensional colorant control signal simplexes that span a domain of the forward device model; and determining a set of range space simplexes in the m-dimensional color space corresponding to the set of n-dimensional colorant control space signal simplexes by mapping the vertices of the n-dimensional colorant control signal simplexes into the m-dimensional color space using the forward device model. The method also includes specifying a point P in the m-dimensional color space; and determining the set of n-dimensional colorant control signals that map to the point P in the m-dimensional color space, by performing m sequential slicing processes through the set of range space simplexes.

Determining sets of n-dimensional colorant control signals

A file of digital color data representing a color image is transformed into a new file of digital color data where one or more colors have been transformed to one or more new color locations where their reproduction is known to be preferred. The digital color data is provided in a multi-dimensional color space where the color locations to be operated on in the color space are designated as color magnets. The color space distance is then calculated between the color locations of the digital color data in the color space and the color magnets. A particular activity is prescribed for each color magnet that affects nearby color locations in the color space; this activity includes one or more activity selected from the group including attraction, repulsion, shielding and dragging. Then, the digital color data is mapped to new locations in the multi-dimensional color space as a function of the color space distance and the selected activity, wherein the degree or strength of activity is a function of the color space distance or direction in color space.

Color transform method for the mapping of colors in images

A method for generating a transform for converting a digital color image signal expressed as color values in a first color space having a first color gamut to code values for driving an output device having a second color gamut different from the first color gamut includes the steps of: transforming the color values of the first color space to color values in an intermediate color space; specifying one or more predefined color regions in an intermediate color space; preferentially mapping the color values in the intermediate color space into the second color gamut by smoothly translating the color values to fit the second color gamut while restricting the mapping to regions outside of the predefined color regions to produce enhanced modified color values in the intermediate color space; and transforming the modified color values to code values for driving the output device.

Color transform method for preferential gamut mapping of colors in images

A method for reducing a bit depth of an image to reduce storage memory, the method comprises the steps of creating a histogram of an image; modifying the histogram so that a maximum slope of a to-be-calculated cumulative histogram will be no greater than substantially 1.0; (c) calculating the cumulative histogram from the modified histogram; and (d) interpreting the cumulative histogram to give a desired bit depth reduction.

Method and system for the reduction of memory capacity required for a digital representation of an image

Color image reproduction apparatus, including a video monitor and a computer-based workstation, provides for modifying an original color image read from an input film and for writing a reproduced image on an output film. A plurality of digitally operated look-up tables (LUTs), associated with the workstation, serve for transforming original imaging data to a common color space (CIELUV L* u* v*) and for transforming reproduced imaging data to different use-dependent RGB color spaces, e.g. video monitor, output film, etc. Color image values stored in each LUT are altered from exact color image values by means of a least squares algorithm to provide an average error of zero--an unbiased error--for linearly interpolated values derived from each LUT.

Growing community of inventors

Alton, NY, United States of America

John R D'Errico