Patent ID: 8897562

Claim:
A method, comprising: performing, by one or more computing devices: obtaining a trimap for a frame in an image sequence comprising a plurality of frames, the trimap indicating a segmentation of an image in the frame into a known foreground region, a known background region, and an unknown region comprising the area between the foreground region and the background region; propagating the unknown region for the frame to a next frame in the image sequence according to optical flow information indicating movement of image content between the frame and the next frame, the propagating of the unknown region according to optical flow information includes: determining, for each of a plurality of portions of the unknown region, which of a warp-based technique and a radius-based technique to use; and using, for each of the plurality of portions of the unknown region, the technique determined for the portion to propagate the portion from the frame to the next frame; and generating a trimap for the next frame according to the propagated unknown region.