sift算法是用来提取图像特征点的算法，性能优越，被广泛用于特征提取和图像匹配，自提出起，算法一直在更新，此为最新版本的sift算法，在matlab上测试可用。(The SIFT algorithm is used to extract the image feature points algorithm, superior performance, is widely used for feature extraction and image matching, since the proposed algorithm, has been updated, this is the latest version of the SIFT algorithm, the test can be used in matlab.)