Patent ID: 8773545

Claim:
An image processing method for executing color conversion processing on input image data by taking into consideration chromatic adaptation characteristics of human visual perception, the color conversion processing being executed so that color appearances under different viewing or illumination conditions become close to each other, comprising: determining a chromatic adaptation transform expression to be used in executing the color conversion processing, the chromatic adaptation transform expression using an adaptation factor indicating a degree to which human visual perception is adapted to a white point under a given illumination condition or viewing condition; preparing in advance relationship information between an optimal adaptation factor and color; determining one or more adaptation factors for the input image, the one or more adaptation factors indicating at least one of: an extent of adaptation to an illumination condition under which a scene where an input image is obtained is illuminated, an extent of adaptation to a viewing condition where the input image is observed, and an extent of adaptation to a viewing condition where an output image is observed; altering the one or more adaptation factors based upon i) the relationship information and ii) at least one of a hue and a saturation of the input image; and executing the color conversion processing for the input image by using the determined chromatic adaptation transform expression using the altered one or more adaptation factors.