Xerox Corporation

Charles Michael Hains

David E Rumph

Robert Roy Buckley

L Dale Green

Jon S McElvain

Robert M Coleman

Michael F Plass

Eric S Nickell

Russell Roger Atkinson

Mark T Corl

James K Kenealy

Reiner Eschbach

Shen-Ge Wang

Sang-Chul Kang

Margaret Motamed

Gwendolyn L Hembrock

Vincent C Lung

John McElvain

Chan Chang

Matthew Tucker

Robert P Loce

Beilei Xu

Martin Sidney Maltz

Gaurav Sharma

William A Fuss

Robert John Rolleston

Keith T Knox

David Jordan Lieberman

James R Low

Mark A Gwaltney

Connie F Purdum

Manu Parmar

Allen Firstenberg

Keith D Collins

A system and method is provided for characterizing color separation misregistration associated with marking a substrate. The method includes providing an input image having a plurality of patches, each patch having a pattern using a first and second color; marking a substrate with a copy of the input image using a first and second color separation to correspond to the first and second colors, respectively; and measuring a color characteristic of markings of respective copied patches of the copied plurality of patches and generating corresponding colorimetric values. Misregistration of the first color separation markings relative to the second color separation markings is characterized based on the measured calorimetric values.

System and method for characterizing color separation misregistration

A system facilitates printing of microtext. A processing component allows a user to create one or more microtext characters, wherein the characters are output as a data packet. An SRE code store receives and associates one or more SRE codes with the data packet, each SRE code is representative of a bit pattern, wherein the bit pattern is a grid of bits that are filled to create a particular pattern. A font bank receives the one or more SRE codes from the SRE code store and defines such codes via a font. A raster image processor receives the font from the font bank, decodes the font and outputs instructions to print the microtext.

Super resolution encoded microprinting through postscript

A preferred embodiment reproduces an image by receiving an input contone array of M contone data values. The contone data values may lie within a range from 1 to N. The embodiment includes comparing each contone data value to an array of M sets of pattern look-up tables to generate an array of M pattern values. M may be a number of one or more. Each pattern value in the array of M pattern values may be decoded to a corresponding K by L multi-pixel pattern of binary data. The binary data is rendered by a reprographic device.

System and method for patterned encoded halftoning

A method is provided for characterizing color separation misregistration of a printer device, the method including receiving from the printer device an output image having marked calibration patches having a variety of color separation configurations, each using a first and second color separation, and a marked measurement patch having a predetermined color separation configuration. Measured colorimetric values are received corresponding to the calibration patches and the marked measurement patch, and a characteristic of a curve associated with the measured colorimetric values corresponding to the calibration patches is determined. A calibration function is generated based on the determined characteristic of the curve, providing expected colorimetric values for the predetermined color separation configuration as related to a misregistration characteristic value. A misregistration characteristic value is determined from the calibration function that corresponds to the measured colorimetric value of the marked measurement patch for characterizing misregistration between the first and second color separations.

System and method for characterizing spatial variance of color separation misregistration

A method and system for estimating color separation misregistration of a printing system. The method may include marking a substrate to form a misregistration estimation patch. The misregistration estimation patch being formed by first and second color separations. The first color separation marking the substrate with a first halftone pattern. The first halftone pattern has a first halftone-frequency vector in a first direction and a second halftone-frequency vector in a second direction. The second color separation marking the substrate with a second halftone pattern. The second halftone pattern has a first halftone-frequency vector in a first direction and a second halftone-frequency vector in a second direction. The first and second halftone patterns form a moir&#xe9; pattern. A deviation in at least one the halftone frequency vectors and/or the moir&#xe9; pattern can be indicative of a color separation misregistration. The method also includes estimating the color separation misregistration of the printing system using the misregistration estimation patch.

System and method for estimating color separation misregistration utilizing frequency-shifted halftone patterns that form a moir&#xe9; pattern

A device for acquiring color images using a color filter array. The color filter array includes a pattern of red array elements, green array elements, and blue array elements. The red array elements and green array elements occur in the color filter array more frequently than the blue array elements. This multiplicity of red, green, and blue color filters adheres closely to known human visual system (HVS) chrominance and luminance responses. Also, the pattern has periodicity in the diagonal directions and is relatively immune to Moire artifacts that arise due to interference between periodic sampling patterns of the CFA and periodic features in imaged scenes.

Color filter pattern for color filter arrays including a demosaicking algorithm

Disclosed herein is an image processing method for producing enhanced halftone edges, particularly suited to those edges which only lie upon the background as apposed to those edges which abut other halftone screens. It utilizes a step of defining border pixels and a step of halftoning those border pixels in a different manner than the halftoning applied to the interior region of the tint or image segment. The preferred halftone for the border pixels will be related to the interior halftone by some number of common spatial frequency harmonics. Examples of common-harmonic screening for an edge include, but are not limited to: (a) same screen with different tone reproduction characteristics (boosted edge values); (b) same screen angles and frequencies with a different spot function, possibly phase shifted; (c) a dot screen whose frequency vectors can be generated by the frequency vectors of the interior screen; (d) a line screen whose frequency vectors can be generated by the frequency vectors of the interior screen. This generation process is directed to ensuring that the two screens will be 'harmonically matched' where at least one of the fundamental frequency vectors and harmonics of the first screen will equal at least one of the fundamental frequency vectors and harmonics of the second screen.

Tinted edge enhancement using harmonic halftones for the boundary pixels

A method of simulating a differential gloss image includes providing a background and a gloss effect image. The gloss effect image is configured for controlling the selective application of first and second halftones to the background image for creation of a differential gloss image when the background image is printed. A mask based on the background image is formed in which regions of mid-tone gray level are accentuated. An edge effect filter may be applied to the gloss effect image to form a filtered gloss effect image. The mask is applied to the filtered gloss effect image to generate a background modified filtered gloss effect image. The background modified filtered gloss effect image is applied to the background image to generate a representation which simulates the differential gloss image.

Glossmark image simulation with application of background modified gloss effect image

An embodiment described below provides a system that allows a user to provide an exact implementation or a close approximation to any desired Holladay dot to a printer with super-resolution encoding (SRE)/decoding (SRD) capabilities. In particular, the embodiment converts a desired Holladay dot to an SRE dot. The SRE dot or SRE look-up table may be uploaded to a printer that supports SRE/SRD.

System and method for creating patterned encoded halftones

This invention is a method of producing a set of TRC's for a color printer's secondary halftone screens that is correlated with the printer's primary halftone screens. The method makes use of the printer/screen characteristic data that is normally gathered during screen calibration. However, instead of progressing from the data to a normal calibration for the secondary screens, the method goes backward through the data starting with the finished primary screen TRC's. The method insures that for every primary screen density, the closest possible secondary screen density is used when the same digital value is specified.

Correlated secondary TRC calibration method

A method and system are provided for producing a print that substantially corresponds to the colorimetric attributes of a corresponding proof for an electronic source file. The method and system entail creating a first raster file corresponding to the electronic source file and a second raster file corresponding to the proof. The first and second raster files are aligned to insure a spatial correlation, and a color conversion data structure is built by comparing the aligned first and second raster files. The color conversion data structure is then used to convert the first raster file to a color converted output file. The color converted output file is color transformed to an output file which is then used to produce the print. The print substantially corresponds to the colorimetric attributes of the corresponding proof for the electronic source file.

System and method for matching colorimetric attributes of a production print to a proof

A method for color cast removal in a scanned image in L*a*b* space includes generating a first color cast correction curve for mapping L* to a first color correction, &#x394;a*, (or &#x394;b*) wherein the first correction curve provides a desired a* shift in midtone regions and is modulated as a function of L* such that black and white points are unaffected; for each pixel n in the scanned image, passing L*through the first color cast correction curve for obtaining a value of &#x394;a*; and adding the value of &#x394;a*to the scanned image's original a*component. To ensure that the color corrected a* remains within gamut, a second correction curve for applying a clipping factor to the mapped &#x394;a* may be generated with the a*passing through the second correction curve for obtaining a clipping factor C; and modifying the a*value by C(&#x394;a*).

Method for color cast removal in scanned images

Historically, the creation of digital line screens was considered to be a subset of the creation of the digital cluster dot screens. The geometric constraints necessary for digital cluster dot screens were imported into the creation of digital line screens. Accordingly, the number of available angles or digital line screens was also significantly limited. In various exemplary embodiments of the systems and methods according to this invention, a digital line screen cell is defined such that the vectors defining the digital line screen cell are not necessarily isometric and are not necessarily at right angles to each other. By using a high-addressability grid that has different resolutions along x and y axis of the grid, the systems and methods according to this invention allow the components of the vectors along the high-addressability direction to be noninteger multiples of the components of the vectors along the other direction of the grid.

Systems and methods for designing digital anamorphic line screens

Conventional design tools were not developed for designing square zero-shift supercells. Conventionally, solutions that enable square zero-shift supercells were found by trial and error or by exhaustive analysis. According to a first design criterion of this invention, a non-square supercell in a first frame of reference has a diagonal that is equal in length to the diagonal of a square supercell in a second frame of reference rotated at a desired screen angle to the first frame of reference. The screen angle is a function of the lengths of the sides of the non-square supercell in the first frame of reference. According to a second design criterion, if the area of the corresponding square supercell in the second frame of reference is an integer, a square zero-shift supercell can be designed based on the lengths of the sides of the non-square supercell in the first frame of reference.

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Altadena, CA, United States of America

Charles Michael Hains