opencv卸载：
先在安装目录下执行
make uninstall
然后删除系统相关文件
cd /usr/
sudo find . -name "*opencv*" | xargs sudo rm -rf
上面一条命令是在当前目录下（包括子目录）查找带有opencv字符串的文件或文件夹并用sudo递归删除
这条命令要写准确了...确保不要删除了一些其他依赖...
如果为了保险，可以用这个
sudo rm -r /usr/local/include/opencv2 /usr/local/include/opencv /usr/include/opencv /usr/include/opencv2 /usr/local/share/opencv /usr/local/share/OpenCV /usr/share/opencv /usr/share/OpenCV /usr/local/bin/opencv* /usr/local/lib/libopencv*
