改程序采用C语言编写SIFT算法，包含完整的从图像高斯金字塔、DOG、空间极值点提取、关键点描述、KDtree匹配等关键步骤的全部函数实现，对全面深入理解Lowe的SIFT算法有莫大帮助。-Change the use of C language program SIFT algorithm, contains the complete Gaussian pyramid from the image, DOG, space extremum point extraction, descr iption of key points, KDtree match the key steps to achieve the full function of the comprehensive and in-depth understanding of Lowe' s SIFT algorithm has great帮助.