sift算子是由D. G. Lowe在1999年提出，2004年完善的一种特征提取的方法，它主要有四个阶段：1）尺度空间极值检测（运用到Gauss函数和difference-of-Gaussian ）2）关键点定位3）定向分配（运用方向直方图，找到一个主方向，主方向的峰值的80%为辅，增强鲁棒性）4）关键点描述符
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SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001174s ]
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SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000978s ]
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