对视频进行运动检测，基于相邻两帧帧间差分。 在相邻两帧（也可以为多帧）间计算逐象素的灰度差，并通过设置阈值来确定对应运动前景的象素，进而得到运动前景区域。-On a video motion detection, based on the two adjacent interframe difference. The gray-scale difference between the two adjacent frames (may be a multi-frame) calculating