python 3.7 安装 openCV==3.4.2.16，opencv-contrib-python==3.4.2.16

第一种方式 :  使用镜像源 

pip install -i https://mirrors.aliyun.com/pypi/simple/ opencv-python==3.4.2.16
pip install -i https://mirrors.aliyun.com/pypi/simple/ opencv-contrib-python==3.4.2.16

第二种方式 :  Python 3.7 安装各个版本的 openCV几个方法

 

opencv 遇到的问题

     1、module 'cv2.cv2' has no attribute 'xfeatures2d'

遇到该问题时，网友多是建议补个包，即
pip install opencv-contrib-python
我在补完之后又出现下面这样的错误：
OpenCV(3.4.3) 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’
貌似是该算法被申请了专利还是咋的，将opencv版本退到3.4.2即可解决，卸载之前的包，然后
pip install opencv-python==3.4.2.16
pip install opencv-contrib-python==3.4.2.16
亲测有效

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