Patent ID: 6204939
Filing Date: 2001-03-20
Classification: H04N

Abstract:
A method for improving accuracy of a transformation implemented by a look-up table that maps colors from a first color space to a second color space for a color image reproduction system comprising an input device and an output device, said method comprises:constructing said look-up table, wherein the entries of said look-up table represent grid points that are derived by interpolation from a relatively small number of non-uniformly spaced points in said first color space,identifying a region of said second color space in which the accuracy of said transformation is to be improved, said region being less than said second color space,obtaining a medium conveying a selected color within said region of second color space,scanning said medium with said input device to obtain first values representing said selected color in said first color space,applying said transformation to map said first values to second values in said second color space and determining a transformation error for said map, andmodifying one or more entries in said look-up table adjacent to said selected color, without increasing the number of entries in said look-up table and without changing the structure of said look-up table, to effect a change in said transformation so as to reduce said transformation error.