Patent ID: 6023351
Filing Date: 2000-02-08
Classification: G06K,H04N

Abstract:
A method for generating a color look-up table by which color values in a first color space are converted to color values in a second color space, the color look-up table being defined by regular grid points with a fixed grid interval therebetween, comprising:obtaining empirical measurements in the second color space for a first set of plural color values in the first color space, the first set of plural color values being substantially all color values at grid points on a first grid interval, wherein the first grid interval is larger than the fixed grid interval;obtaining empirical measurements in the second color space of a second set of plural color values in the first color space, the second set of plural color values being color values at intermediate points between the grid points on the first grid interval;selecting the fixed grid interval for the color look-up table, the fixed grid interval being smaller than the first grid interval and encompassing at least some of the grid points; andcalculating an entry for the color look-up table at each and every grid point defined by the fixed grid interval, wherein in a case where a grid point corresponds to a grid point for which an empirical measurement was obtained in said first and second obtaining steps, the entry for such grid point is equal to such empirical measurement, and wherein in a case where a grid point does not correspond to an empirical measurement obtained in said first and second obtaining steps, the entry for such grid point is equal to a calculated value obtained from a weighted average of empirical measurements adjacent such grid point.