At least one processor of an image processing system acquires a target object image including a target object. The at least one processor detects, from the target object image, a plurality of line segments located relatively on an outer side based on predetermined line segment detection processing. The at least one processor acquires, based on the plurality of line segments, information about an outline of the target object in the target object image. The at least one processor processes, based on the information, at least a part of the target object image so that the outline matches or approximates a predetermined outline.

At least one processor of an image processing system acquires a target object image including a target object. The at least one processor detects, from the target object image, a plurality of line segments located relatively on an outer side based on predetermined line segment detection processing. The at least one processor acquires, based on the plurality of line segments, information about an outline of the target object in the target object image. The at least one processor processes, based on the information, at least a part of the target object image so that the outline matches or approximates a predetermined outline.