Key Frame Extraction based on frame blocks differential accumulation

Key Frame Extraction is a key step for video content analysis and video retrieval. According to the motion of object and camera, a method of key frame extraction based on frame blocks differential accumulation with double thresholds is proposed. Firstly, image frames are partitioned into equal-sized sub-images. Then the blocks in current frames are compared with the corresponding blocks in last extracted key frame to detect weather their contents changed. At last, the key frames of the video can be determined by the number of blocks whose contents changed a lot. The experiment results show that this method has a satisfactory efficiency.