Method and apparatus for trajectory estimation, and method for segmentation

A trajectory estimation apparatus for estimating a trajectory of a subregion constituting all or part of a moving object in a video, said trajectory estimation apparatus comprising:

• an image acceptance unit configured to accept images included in the video, the images being temporally sequential;
• a hierarchical subregion generating unit configured to generate subregions at hierarchical levels by performing hierarchical segmentation on each of the images accepted by said image acceptance unit such that a spatially larger subregion includes spatially smaller subregions, the spatially larger subregion and the spatially smaller subregions belonging to hierarchical levels different from each other;
• and
• a representative trajectory estimation unit configured to estimate, as a representative trajectory, a trajectory, in the video, of a subregion included in a certain image, by (i) searching for a subregion that is most similar to the subregion included in the certain image, across hierarchical levels in another image different from the certain image, and (ii) generating data by chronologically arranging positions of the searched subregion in each of the images,
• wherein said representative trajectory estimating unit (i) generates a predictive subregion, which is a subregion predicted in the other image and is a template for searching, by estimating, as the template, a set of corresponding points which are destinations of trajectories belonging to the subregion included in the certain image, and (ii) obtains the representative trajectory by searching for the subregion that is the most similar to the predictive subregion, across the hierarchical levels in the other image, and generating data by chronologically arranging positions of the searched subregion in each of the images.

A non-transitory computer-readable recording medium on which a program for estimating a trajectory of a subregion constituting all or part of a moving object in a video is recorded, the program causing a computer to execute:

• accepting images included in the video, the images being temporally sequential;
• generating subregions at hierarchical levels by performing hierarchical segmentation on each of the images accepted in the accepting such that a spatially larger subregion includes spatially smaller subregions, the spatially larger subregion and the spatially smaller subregions belonging to hierarchical levels different from each other;
• and
• estimating, as a representative trajectory, a trajectory, in the video, of a subregion included in a certain image, by (i) searching for a subregion that is most similar to the subregion included in the certain image, across hierarchical levels in another image different from the certain image, and (ii) generating data by chronologically arranging positions of the searched subregion in each of the images,
• wherein in the estimating, (i) a predictive subregion, which is a subregion predicted in the other image and is a template for searching, is generated by estimating, as the template, a set of corresponding points which are destinations of trajectories belonging to the subregion included in the certain image, and (ii) the representative trajectory is obtained by searching for the subregion that is the most similar to the predictive subregion, across the hierarchical levels in the other image, and generating data by chronologically arranging positions of the searched subregion in each of the images.