Patents by Inventor James Z. Chang

James Z. Chang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7742206
    Abstract: Embodiments of the present invention comprise methods and systems for color gamut mapping. Some embodiments comprise mapping by projecting a first gamut color point to an intermediate curvilinear construct and then projecting from the curvilinear construct to a second color gamut point. In some embodiments, gamut points are separated into regions with differing projection rules and curvilinear constructs.
    Type: Grant
    Filed: February 8, 2005
    Date of Patent: June 22, 2010
    Assignee: Sharp Laboratories of America, Inc.
    Inventors: John C. Dalrymple, James Z. Chang
  • Patent number: 7019868
    Abstract: A method of determining colorant amounts to be laid down in a color printer includes determining an initial set of cyan, magenta and yellow (CMY) values; ordering the initial set of CMY values to determine the largest, middle and smallest values of the three values and generating an ordering vector; selecting a gamut center black generation LUT and two gamut boundary black generation LUTs from a set of black generation LUTs from a selection table; indexing the selected black generation LUTs to determine black values for each black generation LUT as a function of the minimum of the CMY values; interpolating a final output black colorant amount from the black values, and interpolating final output CMY colorant amounts from the initial set of CMY values, the maximum CMY ink limit constraint, and a set of boundary threshold values.
    Type: Grant
    Filed: December 19, 2000
    Date of Patent: March 28, 2006
    Assignee: Sharp Laboratories of Ameirca, Inc.
    Inventors: James Z. Chang, William C. Kress
  • Patent number: 6650438
    Abstract: A method of transforming scanned RGB values into a colorimetric color space includes identifying multiple input media types to be scanned; assigning a weighting factor to each input media type; dividing input color space into segments; assigning a weighting factor to each input color space segment; applying regression and interpolation techniques to minimize color error; and generating a colorimetric output.
    Type: Grant
    Filed: December 1, 1999
    Date of Patent: November 18, 2003
    Assignee: Sharp Laboratories of America, Inc,
    Inventors: William C. Kress, James Z. Chang
  • Publication number: 20020113982
    Abstract: A method of determining colorant amounts to be laid down in a color printer includes determining an initial set of cyan, magenta and yellow (CMY) values; ordering the initial set of CMY values to determine the largest, middle and smallest values of the three values and generating an ordering vector; selecting a gamut center black generation LUT and two gamut boundary black generation LUTs from a set of black generation LUTs from a selection table; indexing the selected black generation LUTs to determine black values for each black generation LUT as a function of the minimum of the CMY values; interpolating a final output black colorant amount from the black values, and interpolating final output CMY colorant amounts from the TO initial set of CMY values, the maximum CMY ink limit constraint, and a set of boundary threshold values.
    Type: Application
    Filed: December 19, 2000
    Publication date: August 22, 2002
    Applicant: Sharp Laboratories of America, Inc.
    Inventors: James Z. Chang, William C. Kress