Patent ID: 8368957
Filing Date: 2013-02-05
Classification: H04N

Abstract:
1. An image dependent gamut mapping method for mapping source colors of an image to destination colors reproducible by a printing apparatus, said source colors and destination colors being part of a color space comprising a lightness axis, each source color having a lightness component within a range between a source white point and a source black point on the lightness axis, and each destination color having a lightness component within a range between a destination white point and a destination black point on the lightness axis, said method comprising the steps of determining a composed transfer function that maps the source white point onto the destination white point and the source black point onto the destination black point; and applying the composed transfer function on each lightness component of source colors of at least a part of the image; wherein said step of determining comprises the steps of: dividing the lightness axis between the source white point and the source black point into a plurality of pieces; defining for each piece resulting from said step of dividing, a linear mapping from said piece to a part of the lightness components of the destination colors, said linear mapping having a steepness, the value of which has to be determined; defining the composed transfer function as a composed linear mapping consisting of the plurality of linear mappings from said step of defining the linear mapping; and determining the steepness of each linear mapping of the composed transfer function by the steps of: