说明：  （1）ICCV1999 Object Recognition from Local Scale-Invariant Features.pdf提出（2）IJCV2004 Distinctive image features from scale invariant keypoints.pdf总结（3）CVPR2004 PCA-SIFT：A More Distinctive Representation for Local Image Descriptors.pdf加PCA降维
((1) ICCV1999 Object Recognition from Local Scale-Invariant Features.pdf proposed (2) IJCV2004 Distinctive image features from scale invariant keypoints.pdf summary (3) CVPR2004 PCA-SIFT: A More Distinctive Representation for Local Image Descriptors.pdf plus PCA down Victoria)