下载以下压缩包(https://download.csdn.net/download/qq_42928559/60328220?spm=1001.2014.3001.5503)，放入你自己的路径下。很多坑我都踩过了，压缩包里把必要的文件都放在一起了，包括对应的contrib版本。亲测可用
下载之后，进入安装目录下，依次运行以下命令：
mkdir build
cd build
cmake -DWITH_GTK_2_X=ON -DWITH_CUDA=OFF -DOPENCV_EXTRA_MODULES_PATH=/home/car/Downloads/installpkg/opencv-3.3.0/opencv_contrib-3.3.0/modules ..
make -j8
sudo make install
以上的“/home/car/Downloads/installpkg/opencv-3.3.0/opencv_contrib-3.3.0/modules”替换为你自己的目录即可
cuda:
https://blog.csdn.net/DeepOscar/article/details/108245172
cmake -DWITH_GTK_2_X=ON -DWITH_CUDA=ON -DOPENCV_EXTRA_MODULES_PATH=/home/car/Downloads/installpkg/opencv-cuda/opencv_contrib-3.3.0/modules …
nvcc fatal : Unsupported gpu architecture ‘compute_20’
https://blog.csdn.net/kemgine/article/details/78781377
error: identifier “__half2float” is undefined
cmake -DWITH_GTK_2_X=ON -DWITH_CUDA=ON -DOPENCV_EXTRA_MODULES_PATH=/home/car/Downloads/installpkg/opencv-4.2.0/opencv_contrib/modules …