Image processing device, image processing method, and image processing program

Disclosed is an image processing device that can reduce the computational burden of image processing pertaining to character motion and express appropriate motion in which a given part of a character makes precise contact with a contactable object. Said image processing device (100): generates motion information by mixing a plurality of sets of sample motion information in accordance with arbitrary mixing ratios; determines the reachable positions (P) that a character (C) can reach when moved in accordance with the generated motion information; associates the mixing ratios with coordinate information that indicates the determined reachable positions (P); associates each reachable position (P) with a virtual sphere (B) disposed in a virtual space such that said reachable position (P) lies thereon; outputs virtual spheres in accordance with the state of the character (C) in the virtual space on the basis of virtual sphere information; accepts the selection of a virtual sphere that contacts a contactable object; and controls the motion of the character (C) on the basis of the motion information corresponding to the mixing ratio associated with the coordinate information indicating the reachable position (P) associated with the selected virtual sphere.