IMAGE PROCESSING METHOD, IMAGE PROCESSING APPARATUS, AND PROGRAM

Every time clustering processing for a predetermined number of pixels is complete, a small cluster having the number of allocated pixels, which is equal to or smaller than a pixel count threshold, is discriminated. The small cluster, which is discriminated to have the number of allocated pixels equal to or smaller than the pixel count threshold, is merged to a cluster having the nearest representative feature vector. With this arrangement, the number of clusters which are to undergo distance calculations of feature vectors is reduced. According to this arrangement, region segmentation of an image can be executed faster by the clustering processing.