Patent ID: 7417762

Claim:
A method for forming a color conversion table including plural data which, according to the correlation between a first color space and a second color space as defined by a prescribed number of previously acquired sample data, defines the correlation between the first color space and the second color space, the method comprising: a step of setting, in the first color space, target coordinates with respect to which the correlation is defined; a step of setting, in the second color space, conversion object coordinates; a step of converting the conversion object coordinates into corresponding coordinates in the first color space according to the sample data; a step of carrying out a trial process involving the step of setting conversion object coordinates and the step of converting them so as to decrease the difference between the corresponding coordinates in the first color space as obtained by the conversion step and the target coordinates; wherein the conversion object coordinates are provided by calculating a variation of the conversion objects coordinates and the variation of the conversion objects coordinates is calculated by multiplying partial derivatives of the components in the difference with a variation in the second color space at a minute variation of the first color space; a step of generating color conversion table data which defines the correlation between the conversion object coordinates in the second color space and the target coordinates when the difference becomes smaller than a prescribed threshold at the trial step; and a step of storing the color conversion table data in a memory device.