A color original image is divided into many picture elements and each picture element is resolved into three colors of red, green, and blue lights to photometrically measure them and a histogram of hue values is obtained in accordance with the data obtained through photometry. The obtained histogram is divided into mountains, it is judged which divided mountain each picture element of the color original image belongs to in order to classify the picture elements into groups corresponding to the divided mountains and divide the color original image every group. Then, at least one of the divided regions is selected to extract the data for the selected region as feature image data.
Method of extracting feature image data and method of extracting person's face data