A normal image representing a normal structure of a predetermined structure in an input medical image is generated with higher accuracy. Further, an abnormal component in the input medical image is separated with higher accuracy. A supervised learned filtering unit inputs an input image representing a predetermined structure to a supervised learned filter to generate an image representing a normal structure of the predetermined structure. The supervised learned filter is obtained through a learning process using supervisor images, each representing a normal structure of the predetermined structure in a subject (individual), and corresponding training images, each containing an abnormal component in the corresponding subject (individual). Further, a difference processing unit separates an abnormal component in the input image by calculating a difference between the input image and the image representing the normal structure.