lower的原版关于sift算法的资料，很难找的哦。本文非常详细的介绍了sift算法，并与常用的边缘检测算法作了比较，是学习sift算法的好资料。-lower of the original information on the sift algorithm, it is difficult to find, oh. This very detailed introduction to the sift algorithm, and with commonly used edge detecti