example-go-opencv

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example-go-opencv

Install OpenCV on Ubuntu

Install prerequisites

sudo apt-get install cmake gcc g++
sudo apt-get install cmake gcc g++ python3-dev python3-numpy 
sudo apt-get install libavcodec-dev libavformat-dev libswscale-dev libgstreamer-plugins-base1.0-dev libgstreamer1.0-dev
sudo apt-get install libgtk-3-dev
sudo apt-get install libpng-dev libjpeg-dev libopenexr-dev libtiff-dev libwebp-dev

Get OpenCV sources

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

Build OpenCV

cd opencv
mkdir build && cd build
cmake -D OPENCV_GENERATE_PKGCONFIG=YES ..
make
sudo make install

NB: Flag -D OPENCV_GENERATE_PKGCONFIG=YES is used to avoid following error:

# pkg-config --cflags  -- opencv4
Package opencv4 was not found in the pkg-config search path.
Perhaps you should add the directory containing `opencv4.pc'
to the PKG_CONFIG_PATH environment variable
No package 'opencv4' found

It generates and installs a file opencv4.pc in /usr/local/lib/pkgconfig/opencv4.pc. Add following line to the .bashrc

export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig/opencv4.pc

On error finding shared libraries

error while loading shared libraries: libopencv_dnn.so.4.5: cannot open shared object file: No such file or directory

Try to find missed library with a command sudo find / -name "libopencv_dnn.so.4.5" and add the found path to environment variable LD_LIBRARY_PATH in the .bashrc

export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib

With fixed LD_LIBRARY_PATH go-application can be run with command go run main.go, but to run it with JetBrains GoLand - update system cache

sudo ldconfig

Some details about C-libraries.

Source the updated .bashrc file

source ~/.bashrc

Run the example

go run main.go

More details about using Go with OpenCV