SIFT（Scale-invariant feature transform）是一种检测局部特征的算法，该算法通过求一幅图中的特征点（interest points,or corner points）及其有关scale 和 orientation 的描述子得到特征并进行图像特征点匹配，获得了良好效果(It is an algorithm for detecting local features. The algorithm obtains good results by finding features of the feature points (interest points, or corner points) and the descr iptors of scale and orientation in a graph and matching the image feature points.)