Image processing apparatus and image processing method

There is disclosed a method for converting color image data inputted from an image input apparatus to a color space which is not dependent on the apparatus and/or lighting with a high precision, the method comprising: setting a plurality of sets of a subject as a main constituting element of an image inputted from the image input apparatus, means for estimating color data which is not dependent on the apparatus and/or the lighting for each set, judging whether or not each pixel of the image data inputted from the image input apparatus belongs to the set of the subject, and selecting the estimating means based on a judgment result to estimate the color data which is not dependent on the apparatus and/or the lighting; learning a distribution of a specified object for each set in the color space after color conversion during color conversion of the image, performing tentative color conversion from an input image signal, and using the signal after the tentative color conversion to judge the set to which each pixel belongs in the color space after the color conversion; or judging/indicating the set by a user, and subjecting each judged set to a different color conversion processing.