绝对的lowe老人家提出的sift算法源码，配套有文档说明，对于初学者极度有用，还有我添加的注释我移植的仿射变换函数，绝对值得下的资源~！-The absolute lowe elderly sift algorithm proposed source code, supporting have documented for beginners extremely useful, and I add comments I transplanted affine transformation fu