1. An image processing method for extracting a region having a specific feature, the image processing method comprising: extracting pixels representing an object, to which the pixel having the specific feature belongs, from a given input image based on an image feature other than color; extracting principal colors from the pixels; selecting, from a plurality of pre-trained color distribution models deposited in a repository, a color distribution model closest in distance metric to the extracted principal colors by performing a search through the repository using the extracted principal colors, the distance metric indicating distance relative to the extracted principal colors; and segmenting the input image by categorizing pixels in the input image using the selected color distribution model.