1利用SIFT关键点进行图像匹配

2在视频中，在一帧中检测关键点，之后利用canonical patch传递关键点，经过一定阈值的帧后，再次计算关键点，利用相邻帧之间关键点的差别很小，只更新关键点的位置，提高帧率。

3阈值自动确定-1 uses SIFT image matching key points

2 in the video, detecting critical points in one frame, after which it canonical patch transfer key, the frame after a certain threshold value, calculating the key points again, the use of the difference between adjacent frames is small critical point, only the update key position, to improve the frame rate.

3 threshold is determined automatically