Abstract: What is disclosed is a system and method for improving image quality of a color of interest using a cluster model in a color printing system involving the following. First, one or more image quality attributes are selected for a target color marking device. A cluster model is received which comprises a plurality of clusters with each cluster having an associated transform. The cluster model is used to estimate an image quality parameter. The image quality parameter is used to select colorant sets and thereby to improve the image quality in the marking device. Various embodiments of the use of cluster models are disclosed.

Abstract: Systems and methods for implementing use of customer documents in maintaining image quality or image quality consistency of printing devices are provided. The system may include a marking engine constructed to print images on an image bearing surface of the print device; one or more color measuring devices for measured toner images formed on the image bearing surface corresponding to the one or more relevant pages, and an image analyzer configured to generate reference images and to compare measured image data with the reference images. The image analyzer may also be configured to analyze input image data for a document and to identify one or more relevant pages of the document that may provide information regarding the state of the printing system to generated reference image data. Comparisons between the color separations of the reference image data and measured image data images may be realized for determining defects.

Abstract: What is disclosed is a novel system and method for updating a cluster model for color control. In one example embodiment, a cluster model is received and analyzed to identify clusters therein. Each of the identified clusters has an associated transform. Thereafter, in response to a threshold event having occurred, a critical cluster is identified and a critical color is identified from the cluster. Steps for identifying a critical color are more fully described herein. A selected number of patches is then printed in each of the critical colors and color measurements are obtained from the printed patches using, for instance, a colorimeter or spectrophotometer. If the color measurements have deviated beyond a defined threshold, then update the cluster model by: updating the transform associated with the cluster; redefining the number of clusters; redefining a center of any of the clusters; or redefining a boundary of the clusters.

Abstract: Colorant recipes for spot colors, or colors associated with vector graphic objects, are transformed to compensate for spatial variation in a rendering device. Inverted Jacobians of color production performance can be used to transform color deviations into colorant recipe changes. The colorant recipe changes are applied to original colorant recipes to provide the transformed colorant recipes. Jacobians can be determined by exercising a system model according to perturbations of the colorant recipes. Alternatively, test patches or strips based on perturbed original colorant recipes can be rendered and measured and the Jacobians can be based on such measurements. Alternatively, spatially dependent tone reproduction curves can be used to transform the colorant recipes associated with the vector graphic objects. Image processing systems can include a spatial variation information determiner, a spatial compensation information determiner and a colorant recipe transformer.

Abstract: A system and method detect missing inkjets in an inkjet image generating system. The system and method generate digital images of printed documents that do not have test pattern data within them. The digital images are processed to detect light streaks and the positions of the light streaks are correlated to inkjet positions in printheads. Identification of the ink color associated with the correlated inkjet positions are obtained with analysis of color separated images and/or color errors.

Abstract: What is disclosed is a novel system and method for obtaining optimum CMYK values for spot colors, with significantly lower computational effort, by using a set of printer profiles with different pre-computed GCR strategies. Various versions are discussed on how to utilize and/or choose among these profiles for each spot color. The present invention is applicable to spot color emulation for CMYK as well as N-color printing, and can be used to optimize one or more image quality attributes, including graininess, mottle, color stability, ink cost, etc. Various embodiments are disclosed.

Abstract: A computer-implemented method for color calibration and profiling of an output device includes measuring a color patch in a test pattern, which comprises a plurality of color patches, to obtain first image data; measuring the color patch in the test pattern to obtain second image data; transforming the first image data to a first estimated image data; determining a difference between the second image data and the first estimated image data to obtain a correction factor; and calculating, for each patch in the test pattern, a corrected image data by applying the correction factor to a subsequent estimated image data from the first sensor. The correction factor is used for correcting inaccuracies introduced when the first image data is transformed into the first estimated image data. The first image data and the second image data provide a measured color representation of the color patch in a device dependent color space and a device independent color space, respectively.

Abstract: The present disclosure provides processes for producing images of excellent color fidelity when incorporating a magenta toner with a lower colorant loading in addition to a first magenta toner. In embodiments, the magenta pigmented particles may be magenta emulsion aggregation toners. In accordance with the present disclosure, a pair of magenta toners are matched in color, wherein the color of a first magenta toner printed at a predetermined halftone area coverage on a substrate substantially matches the color of the solid (100%) printed patch of the second magenta toner, which is lighter than the first magenta toner, thus avoiding a visible hue shift on the print that would otherwise be objectionable.

Abstract: The present disclosure provides processes for producing images of excellent color fidelity when incorporating a magenta toner with a lower colorant loading in addition to a first magenta toner. In embodiments, the magenta pigmented particles may be magenta emulsion aggregation toners. In accordance with the present disclosure, a pair of magenta toners are matched in color, wherein the color of a first magenta toner printed at a predetermined halftone area coverage on a substrate substantially matches the color of the solid (100%) printed patch of the second magenta toner, which is lighter than the first magenta toner, thus avoiding a visible hue shift on the print that would otherwise be objectionable.

Abstract: Color management constraints on the use of selected hypocolorant(s) and a black colorant in the rendering of a given pixel reduce ink or toner usage and/or reduce pressure on an ink limit. Additionally, the enforcement of this mutual exclusivity between the black and the selected hypocolorant(s) allows screen frequencies and angles to be shared between halftone screens used for the black colorant and a selected hypocolorant. This reduces the likelihood of objectionable moiré associated with the use of hypocolorant colorants in addition to the conventional CMY(K) colorants. In some embodiments, color management constraints prevent the use of black colorant for pixels beyond a threshold lightness or luminance. This constraint allows the use of the selected hypocolorants in the region of color space beyond the threshold. The threshold can be a function of hue and/or chroma. In some embodiments the threshold is a constant.

Abstract: A de-warp map is generated by applying principal component analysis (PCA) to vectors describing aspects of identified features of an object in an image. PCA provides vectors and coefficients describing curvature or image warping at selected points in the image. Estimates of the warping of the image generally are generated by interpolation and/or extrapolation from the vectors and coefficients provided by PCA. In some applications only two features need be identified. For example, the complicated curvature of the facing pages of an open book can be characterized by two vectors describing positions of top and bottom edges of the book. In such applications PCA can reduce to vector subtraction to determine a basis vector, vector addition and scaling to determine an average vector and simple assignment of known coefficient values. The de-warping map can be used to generate a de-warped version of the image.

Abstract: What is disclosed is a novel system and method for determining a printer metric in terms of image quality (IQ) over a large complex set of conditions based upon measurements taken over a small simple set of conditions while compensating for printer drift. The present system and method effectively utilizes a predictive model that predicts noise measurements of multi-separations from those of single-separation colors and/or a subset of the multi-separations. Because a model is used to comprehend the metric over the entire gamut, the number of patches is reduced. This reduction enables the method to be used within a machine to dynamically characterize the device's image quality metric. Various embodiments have been disclosed.

Abstract: Images are prepared for blending with a reflection. Angles of incidence and angles or reflection lead to reflections of a viewer appearing to be different than actual size. Accordingly, image preparation can include scaling images of objects to be blended with a reflection to an appropriate size. For a flat specular surface the size is one half the size the object would be if the object were sized to be associated with the feature that is reflected. A viewer will focus on the reflection of the viewer at an object plane. An image associated with the specular surface will be blurred. Accordingly, the preparation can include compensating for the blurring. Preparation can also include reducing an area coverage of the image of the object to no more than about fifty percent of the region of the refection to provide space for the reflection.

Abstract: A method for performing color registration on template media having template markings thereon comprises sensing the template media using a sensor to obtain first image data; printing a test pattern on the template media; sensing the template media along with the test pattern printed thereon using the sensor to obtain second image data; determining an output image data of the test pattern from the first image data, the second image data, and an estimated image data of the template media with the test pattern printed thereon; determining process direction and cross-process direction misregistrations from the output image data; and adjusting printheads based on the process direction and the cross-process direction misregistrations to provide adjusted color registration on subsequent template media.

Abstract: What is disclosed is a novel system and method for determining color profiles based upon optimizing output image spatial noise. For each of a number of selected output colors, spatial noise values for a set of device-dependent color specifications that produce the selected output color are iteratively determined. The set of device-dependent color specifications is generated by varying a subset of colorants in the device-dependent color specifications while changing the remaining colorants to maintain the selected output color. The iterative process improves the spatial noise value, as determined by a spatial noise model, of the device-dependent color specifications that correspond to the selected output color. When an optimum spatial noise value is found, the device-dependent color specification having that spatial noise value is selected as the mapping for the selected device-independent color specification. Various embodiments are disclosed.

Abstract: What is disclosed is a novel system and method for determining printer performance in terms of image quality defects over a large complex set of conditions based on measurements taken over a small simple set of conditions, thus reducing the amount of time, effort, and wasted paper required to obtain the data. The present system and method effectively utilizes a predictive model that predicts noise measurements of multi-separations from those of single-separation colors and/or a subset of the multi-separations. Because a model is used to comprehend color performance over the entire gamut, the number of patches is reduced. This reduction enables the method to be used within a machine to dynamically characterize the device's image quality performance. Various embodiments have been disclosed.

Abstract: What is disclosed is a novel system and method for determining printer performance in terms of image quality (IQ) on-paper using on-belt measurements. First, image noise is measured via sensing of single-separation device-dependent colors on an imaging member for a target marking device. Such single-separation device-dependent colors, in one embodiment, comprise cyan, magenta, yellow and black. A predictive correlation model is used to project the image noise of the single-separation device-dependent colors when printed on a substrate. A noise prediction model is used to estimate image noise performance values of multi-separation device-dependent colors on a substrate from the projected single-separation device-dependent colors on a substrate. In one embodiment, the predictive correlation model comprises a separation-dependent polynomial equation. The estimated image noise performance values on a substrate are used to determine image quality metric of the target marking device.

Abstract: What is disclosed is a novel system and method for determining color profiles based upon optimizing image output color stability. For each of a number of selected output colors, color stability values for a set of device-dependent color specifications that produce the selected output color are iteratively determined. The set of device-dependent color specifications is generated by varying a subset of colorants in the device-dependent color specifications while changing the remaining colorants to maintain the selected output color. The iterative process improves the color stability value, as determined by a color stability model, of the device-dependent color specifications that correspond to the selected output color. When an optimum color stability value is found, the device-dependent color specification having that color stability value is selected as the mapping for the selected device-independent color specification. Various embodiments are disclosed.

Abstract: A light-magenta radiation-curable gel ink including at least one curable monomer, at least one organic gellant, at least one photoinitiator, and a colorant. The colorant includes a magenta colorant, a hue-adjusting colorant that absorbs light having a wavelength of from about 400 to about 500 nm, and an optional shade-adjusting colorant that absorbs light having a wavelength of from about 600 to about 700 nm.

Abstract: A light-magenta solid ink including an ink vehicle and a colorant. The colorant includes a magenta colorant, a hue-adjusting colorant that absorbs light having a wavelength of from about 400 to about 500 nm, and an optional shade-adjusting colorant that absorbs light having a wavelength of from about 600 to about 700 nm.