meanshift

代码说明：

  均值平移跟踪算法中核函数窗宽的自动选取代码，根据目标大小变化核窗宽，使得当目标出现大小变化时准确跟踪到目标中心(Mean shift tracking algorithm in the kernel function automatically selects the window wide code, depending on the target size of changes in the nuclear window width, making small changes occur when the target accurately track to the target when the center)