Installing OpenCV for Python on Ubuntu, getting ImportError: No module named cv2.cv

Question

I have an Ubuntu 14.04 system, on which I want to install OpenCV and use it with Python 2.x.

I installed OpenCV using the instructions here: https://help.ubuntu.com/

Answer 1

Try conda install -c conda-forge opencv if you are using anaconda, it works!

Answer 2

You can build for source following the official OpenCV tutorial. The crucial part is to set the PYTHON3_EXECUTABLE, PYTHON_LIBRARY, PYTHON3_PACKAGES_PATH and PYTHON3_NUMPY_INCLUDE_DIRS parameters for python3.6. Here are all the steps:

1. Clone the repo

   git clone https://github.com/opencv/opencv.git
   

2. Create build directory

   cd ~/opencv
   mkdir build
   cd build
   

3. Configure

   cmake -D CMAKE_BUILD_TYPE=RELEASE \
         -D CMAKE_INSTALL_PREFIX=/usr/local .. \
         -D PYTHON_INCLUDE_DIR=/usr/include/python3.6 \
         -D PYTHON_INCLUDE_DIR2=/usr/include/x86_64-linux-gnu/python3.6m \
         -D BUILD_NEW_PYTHON_SUPPORT=ON \
         -D BUILD_opencv_python3=ON \
         -D HAVE_opencv_python3=ON \
         -D INSTALL_PYTHON_EXAMPLES=ON \
         -D PYTHON3_EXECUTABLE=/usr/bin/python3.6 \
         -D PYTHON_DEFAULT_EXECUTABLE=/usr/bin/python3.6 \
         -D PYTHON_LIBRARY=/usr/lib/x86_64-linux-gnu/libpython3.6m.so \
         -D PYTHON3_PACKAGES_PATH=/usr/lib/python3/dist-packages .. \
         -D PYTHON3_NUMPY_INCLUDE_DIRS=/home/user/.local/lib/python3.6/site-packages/numpy/core/include/
   

4. Build

   make -j8
   

5. Install libraries

   sudo make install
   

6. Test

   python3
   import cv2
   

If you don't get the error "No module named cv2", then the installation was successful.

Note: If you don't know the path to numpy for the PYTHON3_NUMPY_INCLUDE_DIRS parameter, you can find it by executing import numpy and then numpy.__file__ in a python3 shell.

Answer 3

I found a solution in the guide here:

http://www.samontab.com/web/2014/06/installing-opencv-2-4-9-in-ubuntu-14-04-lts/

I resorted to compiling and installing from source. The process was very smooth, had I known, I would have started with that instead of trying to find a more simple way to install. Hopefully this information is helpful to someone.

Answer 4

Try using: from cv2 import cv

It works for me.

Answer 5

If you want as simple as possible, install from the repository:

sudo apt-get install python-opencv libopencv-dev python-numpy python-dev

Answer 6

My environment:

• Ubuntu 15.10
• Python 3.5

Since none of the previous answers worked for me, I downloaded OpenCV 3.0 from http://opencv.org/downloads.html and followed the installation manual. I used the following cmake command:

$ ~/Programs/opencv-3.0.0$ cmake -D CMAKE_BUILD_TYPE=Release -D CMAKE_INSTALL_PREFIX=/usr/local -D PYTHON3_EXECUTABLE=/usr/bin/python3.5 -D PYTHON_INCLUDE_DIR=/usr/include/python3.5 -D PYTHON_INCLUDE_DIR2=/usr/include/x86_64-linux-gnu/python3.5m -D PYTHON_LIBRARY=/usr/lib/x86_64-linux-gnu/libpython3.5m.so -D PYTHON3_NUMPY_INCLUDE_DIRS=/usr/lib/python3/dist-packages/numpy/core/include/ -D PYTHON3_PACKAGES_PATH=/usr/lib/python3/dist-packages ..

Each step of the tutorial is important. Particularly, don't forget to call sudo make install.