SURF only works outside but not inside of my Anaconda environment

Question

I build OpenCV 4.5.5 from source in windows and I activated OPENCV_ENABLE_NONFREE with the help of CMAKE. As I tried 'surf = cv.xfeatures2d.SURF_create(400)' outside of my anaconda environment I am getting no error and it works perfetly...but when I try the same thing inside of my anaconda environment I am getting error module 'cv2' has no attribute 'xfeatures2d'

Answer 1

Instructions how to build open-cv with GPU support on windows on an anaconda environment (also fix for autocomplete not available):

"""
    opencv cuda installation on WINDOWS 10:
    youtube https://www.youtube.com/watch?v=YsmhKar8oOc&ab_channel=TheCodingBug
    ** all links for download in the link
    ** in brackets: my specific installation
    * install anaconda
    * vs studio 19 with "desktop development C++" and "python development"
    * Cuda toolkit (cuda toolkit 10.2)
    * cuDNN - version that match the cuda toolkit above (cuDnn v7.6.5 for Cuda 10.2)
        * archive: https://developer.nvidia.com/rdp/cudnn-archive
        * copy all to cuda (bin to bin, lib to lib, include to include)
        * minimum 7.5
    * CMake
    * openCV source (4.5.2)
    * openCV contrib - same version as openCV above (4.5.2)
        * place openCV and openCV contrib in the same folder and extract both

    1 build a new python env anywhere(conda(base or custom), normal py, venv...)
    2 set 4 system environment variables:
        let PY_PATH be you python dir (conda env, normal py, venv...)
        go to PATH and add the next 4:
            * PY_PATH # for the python.exe
            * PY_PATH/Scripts # for pip...
            * PY_PATH/libs  # for python36.lib file
            * PY_PATH/include # h files
    2b pip install numpy (if you want tf, 1.19.5)
    3 open CMake gui
    * source code: location of openCV source
    * create 2 new dirs in the level of openCV source called build and install
    * where to build: location of build folder created above
    * configure, set generator x64 and finish
    * click grouped checkbox and look in PYTHON3
        should have EXECUTABLE, INCLUDE_DIR, LIBRARY, NUMPY_INCLUDE, PACKAGES paths filled according to PY_PATH
        look at the output and search for OpenCV modules. if python3 in Unavailable - don't continue. it should be
        in the "To be built"
    * extra round of flags:
        WITH_CUDA
        BUILD_opencv_dnn
        OPENCV_DNN_CUDA
        ENABLE_FAST_MATH
        BUILD_opencv_world
        BUILD_opencv_python3 # should already be on
        OPENCV_EXTRA_MODULES_PATH -> set to openCV contrib on modules folder
    * hit configure - in the output you should see your CUDA and cuDNN details
        CUDA detected: x.y (10.2)
        Found CUDNN path ...
    * extra round of flags:
        CUDA_FAST_MATH
        CUDA_ARCH_BIN -> go to https://en.wikipedia.org/wiki/CUDA and look for your GPU. find it's Compute
            capability (version). (my GPU is gtx 1050. version 6.1)
            remove all versions other than you GPU version. (i left only 6.1)
        CMAKE_INSTALL_PREFIX -> place install path from above (you create this dir with build above)
        CMAKE_CONFIGURATION_TYPES -> remove Debug and keep only Release
    * hit configure
    * hit generate
    close CMAKE gui
    4 go to build folder and look for OpenCV.sln
    * goto solution explorer->CMakeTargets-> right click ALL_BUILD and hit build # should take 10-30 mins
    * if done with no errors, right click INSTALL and build.
    * if no errors, openCV cuda is ready
    5 validation: open terminal and write python (should work due to step 2)
    import cv2
    print(cv2.__version__)
    print(cv2.cuda.getCudaEnabledDeviceCount())  # should be >=1
    run this:
        pip install wizzi_utils
        import wizzi_utils as wu
        wu.cvt.test.cuda_on_gpu_test()
    6 cleanup
    * delete all build folder except build/lib # maybe for future use ?
    * delete both zips and extracted open cv and open cv contrib
    7 after checking on pycharm, open cv with GPU support should work but no autocomplete.
    pip install mypy
    stubgen -m cv2 -o ENV_PATH\Lib\site-packages\cv2
    # if the stubgen fails, run as administrator
    # rename cv2.pyi created to __init__.pyi
    # all done
    e.g:
    stubgen -m cv2 -o C:\\Users\\GiladEiniKbyLake\\.conda\\envs\\cv_cuda\\Lib\\site-packages\\cv2
    # a file was created at C:\\Users\\GiladEiniKbyLake\\.conda\\envs\\temp\\Lib\\site-packages\\cv2\\cv2.pyi
    # rename cv2.pyi to __init__.pyi and have the file:
        C:\\Users\\GiladEiniKbyLake\\.conda\\envs\\temp\\Lib\\site-packages\\cv2\\__init__.pyi
    :return:
    """