记录做毕设的一些问题
1、关于SIFT
（1）运行OpenCV程序提示算法未实现：携载opencv-python，安装opencv-contrib-python
（2）行OpenCV程序提示算法版权问题：
OpenCV(4.0.0) C:\projects\opencv-python\opencv_contrib\modules\xfeatures2d\src\sift.cpp:1207: error: (-213:The function/feature is not implemented) This algorithm is patented and is excluded in this configuration; Set OPENCV_ENABLE_NONFREE CMake option and rebuild the library in function 'cv::xfeatures2d::SIFT::create'
尝试安装低版本opencv:3.4.5 失败