Abstract: 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.

Abstract: 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.

Abstract: A method for adjusting dot-gain for a halftone binary bitmap file comprises inputting a halftone binary bitmap file consisting of binary pixels (400) to an asymmetric digital filter (500). The binary pixels are filtered with the asymmetric digital filter and generates multi-level pixels (506). The multi-level pixel are compared to a preset level (408) and generates a binary pixel output (410). The binary pixel output is collected and forms an adjusted halftone binary bitmap file (270).

Abstract: A method for modifying an input digital image having one or more color channels, each color channel having an (x,y) array of image pixel values, to form a modified digital image so that when the modified digital image is used to produce a printed image on an inkjet printer there are reduced ink bleed artifacts.

Abstract: Method for building color transforms for color imaging devices having concave color gamut regions, including forming a device model that relates device control signals for a color imaging device to corresponding device-independent color values in a device-independent color space; forming a device color gamut representing the set of colors in the device-independent color space that are producible by the color imaging device; and forming a convex color gamut by fitting a convex hull to the device color gamut. The method further includes forming an expanded device model that relates device control signals for the color imaging device to expanded device-independent color values in the device-independent color space, such that the expanded device-independent color values fill the convex color gamut; and building a color transform that relates input device-independent color values to corresponding device control signals for the color imaging device using the expanded device model.

Abstract: 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.

Abstract: A method for adjusting dot-gain for a halftone binary bitmap file comprises inputting a halftone binary bitmap file consisting of binary pixels (400) to an asymmetric digital filter (500). The binary pixels are filtered with the asymmetric digital filter and generates multi-level pixels (506). The multi-level pixel are compared to a preset level (408) and generates a binary pixel output (410). The binary pixel output is collected and forms an adjusted halftone binary bitmap file (270).

Abstract: A method for multi-level halftoning an input digital image to form an output digital image which includes a multi-level error diffusion halftoning process incorporating periodic dither signals whose amplitudes are adjusted as a function of the error-diffusion texture characteristics.

Abstract: 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>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.

Abstract: A method for converting an original halftone bitmap image to a color converted halftone bitmap image. A set of asymmetrical morphological filters is provided. The original halftone bitmap image is segmented into blocks and for each block: apply the set of morphological filters to the original halftone bitmap image to produce a set of modified halftone bitmap images; estimate the percent dot area of the original halftone bitmap image and the set of modified halftone bitmap images; a predetermined dot-gain to the percent dot area of the original halftone bitmap image to produce a modified percent dot area; select the modified halftone bitmap image whose percent dot area is closest to the modified percent dot area to produce a block of the color corrected halftone bitmap image; and replace the original halftone bitmap image with the combined blocks of selected modified halftone bitmap image.

Abstract: A method of processing a digital image having pixels to improve the sharpness of a print generated from the digital image including determining a magnification value representing the magnification of a pixel of the digital image on the print based on the number of input digital image pixels and the output number of digital image pixels; producing a filter in response to the magnification value; using the filter to operate on the digital image to adjust the sharpness of the digital image to produce a sharpened digital image; resizing according to the magnification value the sharpened digital image to produce a resized sharpened digital image which includes the output number of digital image pixels; and producing the print based on the resized sharpened digital image.

Abstract: A method for color correcting an original halftone bitmap image by a predefined color correction function to produce a color corrected halftone bitmap image comprising: providing an original halftone bitmap image; estimating the dot area percentage of the original halftone bitmap image in a set of sub-image blocks; calculating an aim dot area percentage, based on a predefined color correction function, for each sub-image block in the original halftone bitmap image, calculating the number of halftone bitmap image pixels to convert to on or off states to produce a modified original halftone bitmap image that has the aim dot area percentage where said value is designated by N, for each sub-image block in the original halftone bitmap image, and converting N pixels in the original halftone bitmap image to either on or off states depending on whether the aim dot area percentage is greater or less than the dot area percentage of the original halftone bitmap image respectively, for each sub-image block in the origina

Abstract: A method for converting an original halftone bitmap image to a color converted halftone bitmap image by morphological filtering of the original image to compensate for tone and color reproduction characteristics comprising: providing an original halftone bitmap image. The method includes providing a set of asymmetrical morphological filters that have the property that when they are applied recursively in order, the features in the halftone bitmap image are dilated or eroded by varying amounts by extending or reducing the edges first in one direction, then in two directions, etc.

Abstract: A method for color correcting an original halftone bitmap image by a predefined color correction function to produce a color corrected halftone bitmap image comprising: providing an original halftone bitmap image; estimating the dot area percentage of the original halftone bitmap image in a set of sub-image blocks; calculating an aim dot area percentage, based on a predefined color correction function, for each sub-image block in the original halftone bitmap image, calculating the number of halftone bitmap image pixels to convert to on or off states to produce a modified original halftone bitmap image that has the aim dot area percentage where said value is designated by N, for each sub-image block in the original halftone bitmap image, and converting N pixels in the original halftone bitmap image to either on or off states depending on whether the aim dot area percentage is greater or less than the dot area percentage of the original halftone bitmap image respectively, for each sub-image block in the origina