PROBLEM TO BE SOLVED: To stably detect a target portion from a moving image with high accuracy.SOLUTION: Candidate information, which contains information on a candidate for at least the outer edge of a target portion in a body of an organism, is extracted from each frame image constituting at least part of a moving image that captures movement of the target portion. Reference information on the target portion is then generated from extracted multiple pieces of candidate information. The target portion is then detected from each of multiple frame images included in the moving image on the basis of the reference information.
