How to cross compile OpenCV for the Raspberry PI Zero?

Question

Hi so I've got a camera module for my Pi Zero and wanted to play around with OpenCV and Python.

Looking around google, if found a few guides to get OpenCV to a Raspberry but most included to either download some compiled code form some random guys github or to compile on the raspberry pi (48h+ no thank you).

Since I did not wanted to do either of these options I looked further and found this guide on cross-compiling OpenCV for Raspberry PI.

I followed it, but later realized that it targets a PI 2/3 and not a Zero, and results in an invalid instruction error on the Zero. So here is my question: What options do I need to change to cross-compile to the raspberry pi zero? Or is it impossible to do that way?

Original command form the Guide.

cmake -D CMAKE_BUILD_TYPE=RELEASE \
 -D CMAKE_INSTALL_PREFIX=/opt/opencv-4.0.0 \
 -D CMAKE_TOOLCHAIN_FILE=../platforms/linux/arm-gnueabi.toolchain.cmake \
 -D OPENCV_EXTRA_MODULES_PATH=~/opencv_all/opencv_contrib-4.0.0/modules \
 -D OPENCV_ENABLE_NONFREE=ON \ 
 -D PYTHON2_INCLUDE_PATH=/usr/include/python2.7 \
 -D PYTHON2_LIBRARIES=/usr/lib/arm-linux-gnueabihf/libpython2.7.so \
 -D PYTHON2_NUMPY_INCLUDE_DIRS=/usr/lib/python2/dist-packages/numpy/core/include \
 -D PYTHON3_INCLUDE_PATH=/usr/include/python3.5m \
 -D PYTHON3_LIBRARIES=/usr/lib/arm-linux-gnueabihf/libpython3.5m.so \
 -D PYTHON3_NUMPY_INCLUDE_DIRS=/usr/lib/python3/dist-packages/numpy/core/include \
 -D BUILD_OPENCV_PYTHON2=ON \
 -D BUILD_OPENCV_PYTHON3=ON \
 -D ENABLE_NEON=ON \
 -D ENABLE_VFPV3=ON \
 -D WIDTH_GTK=ON \
 -D BUILD_TESTS=OFF \
 -D BUILD_DOCS=OFF \
 -D BUILD_EXAMPLES=OFF ..

I already figured out that ENABLE_VFPV3=ON and ENABLE_NEON=ON are wrong, but only removing them dose not work either.

• f321x: See this great guide: solarianprogrammer.com/2019/08/07/… worked flawlessly for me with opencv 4.7.0 on fedora

Answer 1

If im not mistaken you have a compressed opencv package available.

• run pip install opencv-python if you need only main modules
• run pip install opencv-contrib-python if you need both main and contrib modules (check extra modules listing from OpenCV documentation)

I have used this package for basic openCV functionality such as accessing a webcam.

Further Documentation: https://pypi.org/project/opencv-python/

• Heetola: No matching distribution found for opencv-python