Xerox Corporation

Meng Yao

Xing Li

Stephen Michael Kroon

Mark Raymond Parker

Trevor James Snyder

Martin Sidney Maltz

Barbara Lynn Farrell

Michael Thomas Stevens

Michael Dale Stevens

Howard A Mizes

David Jon Metcalfe

Yeqing Zhang

Michael Cameron Gordon

Susan June Zoltner

James Walter Reid

Augustus J Rogers, Iv

Paul W Philippi

John Adam Handwork

Paul W Phillippi

Embodiments relate to systems and methods for a computation-efficient image processing system architecture. Image data can be transmitted from a computer, online service, and/or other image source to an output device having a set of image processing modules in two or more image paths, including an edge detection module and a video decoding module. The edge detection module can produce edge tag output, and the video decoding module, operating in parallel, can generate decoded video output. The edge tag output and decoded video output can be transmitted to a set of downstream image processing modules, including modules for color trapping, edge smoothing, and other operations. Because earlier processing stages share information with downstream modules which require the same or related data, redundant processing can be reduced or eliminated. Complex image operations can therefore be carried out, and high-quality output can be generated, without sacrificing responsiveness.

Systems and methods for computation-efficient image processing system architecture

A method of producing a bit-map including rendering a bit-map of a first image using a first stochastic half-tone screen set, rendering a bit-map of a second image using a second stochastic half-tone screen set, wherein the first half-tone screen set and the second half-tone screen set have respectively associated stochastic half-tone screens, and wherein each half-tone screen of the second half-tone screen set is less than 100 percent correlated with, and not an inverse of, the associated half-tone screen of the first half-tone screen set; and merging the bit-map of the first image with the bit-map of the second image.

Generating and merging two halftoned images

A computer-implemented method and system for enhancing black density of a halftoned bitmap are provided. The method includes receiving a halftoned bitmap into computer memory, and, using a computer, identifying at least one black-only pixel in the halftoned bitmap. The method further includes for each of the identified black-only pixels, identifying at least one black-only pixel as a candidate for adding color based at least in part on the location of the black-only pixel with respect to an edge in the halftoned bitmap, modifying the halftoned bitmap by adding color to at least one of the candidate black-only pixels, and outputting the modified halftoned bitmap.

System and method for enhancing the density of black

A system and method converts pixels of continuous image data to pixels of binary image data using a halftone screen corresponding to a predetermined reduced coverage percentage; determines if a target pixel of binary image data is a non-white pixel; compares a window of pixels of binary image data with a predetermined pattern of pixels of binary image data corresponding to the predetermined reduced coverage percentage; determines that the target pixel is a non-edge pixel; and reduces the number of non-white pixels in the binary image data based upon the determination that the target pixel is a non-edge pixel.

Method and system for preserving image quality in an economy print mode

What is disclosed is a system and method for determining an orientation direction of a color edge at a given pixel location in a binary color image. The orientation direction of the color edge is determined from eight pixel counts with each pixel count being a total number of pixels in each of eight regions of a window centered about a candidate pixel which resides along the color edge. The eight regions are associated with 8 compass points. The orientation of the edge is determined by a 1, 2and 3tier control bits which are based upon the pixel counts of each region. The 1, 2and 3tier control bits collectively form a 3-bit word. The 3-bit word defines the orientation direction. The teachings hereof provide an efficient way of performing binary edge orientation detection by making uses of intermediate results to simultaneously encode the edge orientation.

Determining an orientation direction of a color edge at a pixel location in a color image

A methodology for thin line detection and enhancement in electronic images is disclosed. The methodology includes associating an electronic image with at least one basic context window that is less than the size of the electronic image based on the input image resolution of the electronic image; detecting one or more predefined patterns which correspond to thin lines in the electronic image using the at least one basic context window; excluding patterns for the one or more detected patterns which are halftone patterns; and adding at least one pixel to the electronic image based on at least one of the remaining patterns so as to enhance thin line features in the electronic image. In some implementation, the methodology may be configured to handle electronic images having different resolutions. A system for thin line detection and enhancement in electronic images having different resolutions is also disclosed.

Thin line detection and enhancement for electronic images having different resolutions

Provided are bitmap based trapping methods, apparatus and systems. According to one exemplary method, black trapping color image data is performed by estimating the continuous tone values associated with non-black pixels near a qualified black pixel and subsequently, the estimated continuous tone values are halftoned at the qualified black pixel locations and ORed with the original bitmap data.

Bitmapped based trapping methods, apparatus and system by modifying non-black halftone pixel bitmap plane using estimated continuous tone value

What is disclosed is a novel system and method for determining whether a pixel resides along a two-color edge in a halftoned bi-level bitmap. In one embodiment, a bitmap having a plurality of colored pixels is received. For each pixel in the bitmap, a window of size n&#xd7;m is defined centered on the current pixel. The window is partitioned into a plurality of regions with each region having an orientation direction with each orientation direction having an associated numeric value. A number of pixels are counted for each of the first and second colors in each of the associated orientation directions. A determination is made as to the respective orientation direction having the maximum and minimum pixel counts for each of the first and second colors. Thereafter, a determination is made whether the pixel resides along a two color edge based upon the max/min counts and each associated orientation direction.

Color trapping on a halftoned bi-level bitmap

What is provided herein is a novel system and method which improves efficiency of a color management system performing a gamut mapping function. In one embodiment, a plurality of source colors are examined to determine whether any have changed. If not, then the source profile, the source device model, and the color appearance model have not changed. Next, the primary colors of the destination device are examined to determine whether any of these have changes. If these have not changed, then the destination device profile and the destination device model have not changed. When the source profile, device profile, color appearance model and the device models have not changed, gamut mapping does not have to be performed. The cached gamut mapping data are used instead. The gamut mapping data are used in subsequent mappings between these same two devices. The cached gamut mapping data are used to customize a color response of the destination device.

Caching for color management systems performing a gamut mapping function

What is disclosed is a novel system and method for color trapping on halftoned bi-level bitmaps. Color edges are detected and edge pixels that need to be trapped are identified. The number of pixels qualified as edge pixels eligible for color trapping can be up to a pre-determined number of pixels away from the color edge. Estimates for the continuous-tone values are obtained for the dominant colors on each side of the two-color edge. The contone value of the dominant color on the opposing side of the two-color edge is assigned to the qualified edge pixels. Qualified edge pixels are re-halftoned using their assigned contone value so that halftones for one color are extended beyond the edge into the other color. The re-halftoned edge pixels are combined with the original bitmap to produce a new bitmap for the image. The new bitmap is then provided to an image output device.

A method of operating a color printer including using a first set of one-dimensional TRCs or a second set of one-dimensional TRCs with a single set of color tables.

Color printing

A mapping technique is disclosed that maps color image data of an image displayed on a first image display device to output color image data for display on a second image display device. This mapping technique maps the color gamut of the first image display device to the color gamut of the second image display device while controlling one or more characteristics of the color image data, and generates one or more lookup tables that correspond to the gamut mapping, for example. The color image data is then mapped to the output color image data based on the lookup tables.

Gamut mapping

What is disclosed is a novel system and method for reducing process color banding due to printhead non-uniformities in a direct marking device. In one example, a first measurement of a printhead spatial non-uniformity is obtained along a first line in a color space which produces a spatial uniformity when a target primary color is printed alone. A first spatial tone reproduction curve is generated. A second measurement of the printhead spatial non-uniformity is obtained along a second line in color space in a coverage area of a process color which maximally changes a halftone structure of the target primary color. A second spatial TRC is generated. The first and second spatial TRCs are combined using a weighted average which balances the primary and process colors. A modified spatial TRC is generated. The printhead is adjusted at a location of the target primary color according to the modified spatial TRC.

Reducing printhead process color non-uniformities in a direct marking device

An imaging system that forms an image on a receiving medium including a fluid ejector that ejects fluid onto the receiving medium and a controller that controls the fluid ejector to eject the fluid to include a non-white and non-clear fluid or one of at least white and clear W fluid on each pixel on the receiving medium. A substantially single layer of fluid is ejected onto the receiving medium. A method for forming an image on a receiving medium includes ejecting a fluid onto the receiving medium, and controlling the ejection of the fluid to include a non-white and non-clear fluid or one of at least white and clear fluid for each pixel on the receiving medium.

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West Linn, OR, United States of America

Meng Yao