Method and apparatus for trajectory estimation, and method for segmentation

A trajectory estimation apparatus includes: an image acceptance unit which accepts images that are temporally sequential and included in the video; a hierarchical subregion generating unit which generates subregions at hierarchical levels by performing hierarchical segmentation on each of the images accepted by the image acceptance unit such that, among subregions belonging to hierarchical levels different from each other, a spatially larger subregion includes spatially smaller subregions; and a representative trajectory estimation unit which estimates, as a representative trajectory, a trajectory, in the video, of a subregion included in a certain image, by searching for a subregion that is most similar to the subregion included in the certain image, across hierarchical levels in an image different from the certain image.