sift算子在图像匹配与图像拼接三维重建中都有重要地位，这个程序没有使用opencv，原作者很不容易写出来的。在调试中会有少量问题，稍加调试就可调通 -sift operator in image matching and 3D reconstruction image mosaic has an important position, this program does not use opencv, the original author is not easy to write out.