从视频中提取关键帧，以若干张图片替代视频关键内容。-Key frame extraction from video to video a number of key elements of alternative images.

压缩域的视频I帧提取，提取出来的关键帧作为视频的关键帧，用于视频拷贝检测-Compressed domain video I frame extraction, the extracted key frames as a video keyframe for video copy detection