1. An image processing method comprising: (a) extracting, using a processor, an interest feature index from an input image based on a depth sensation estimation cue existing in the image; (b) calculating an interest feature index integration map by combining the extracted interest feature index and an importance of interest calculated for the depth sensation estimation cue; and (c) performing discrimination processing of the image based on the interest feature index integration map, wherein the importance of interest is adjusted according to at least one of how much the depth sensation estimation cue affects human perception and how the interest feature index is distributed in the image.