计算感兴趣区域内的光流特征，建立加权方向直方图，根据直方图统计感兴趣区域的主运方向和速度幅值。读取视频流，得到一段时间内运动目标的速度大小和方向变化。-Optical flow characteristics within the region of interest is calculated, and establish a weighted direction histogram, according to the master of the histogram region of int