This page has information on how to install and use GoCV on Ubuntu, as well as other Linux distros.
You can use make to install OpenCV 4.9.0 with the handy Makefile included with this repo. If you already have installed OpenCV, you do not need to do so again. The installation performed by the Makefile is minimal, so it may remove OpenCV options such as Python or Java wrappers if you have already installed OpenCV some other way.
Install the GoCV package:
go get -u -d gocv.io/x/gocv
Change directories into the newly installed package directory:
cd $GOPATH/src/gocv.io/x/gocv
Now you can run the needed installation steps listed below.
The following commands should do everything to download and install OpenCV 4.9.0 on Linux:
make install
If it works correctly, at the end of the entire process, the following message should be displayed:
gocv version: 0.36.0
opencv lib version: 4.9.0
That’s it, now you are ready to use GoCV.
Here are details for each of the steps that are performed during the “Quick Install”. If you have already run make install as described above, you do not need to run any of these commands.
First, you need to update the system, and install any required packages:
make deps
Now, download the OpenCV 4.9.0 and OpenCV Contrib source code:
make download
Build everything. This will take quite a while:
make build
Once the code is built, you are ready to install:
make sudo_install
To verify your installation you can run one of the included examples.
First, change the current directory to the location of the GoCV repo:
cd $GOPATH/src/gocv.io/x/gocv
Now you should be able to build or run any of the examples:
go run ./cmd/version/main.go
The version program should output the following:
gocv version: 0.36.0
opencv lib version: 4.9.0
After the installation is complete, you can remove the extra files and folders:
make clean
By default, pkg-config is used to determine the correct flags for compiling and linking OpenCV. This behavior can be disabled by supplying -tags customenv when building/running your application. When building with this tag you will need to supply the CGO environment variables yourself.
For example:
export CGO_CPPFLAGS="-I/usr/local/include"
export CGO_LDFLAGS="-L/usr/local/lib -lopencv_core -lopencv_face -lopencv_videoio -lopencv_imgproc -lopencv_highgui -lopencv_imgcodecs -lopencv_objdetect -lopencv_features2d -lopencv_video -lopencv_dnn -lopencv_xfeatures2d"
Please note that you will need to run these 2 lines of code one time in your current session in order to build or run the code, in order to setup the needed ENV variables. Once you have done so, you can execute code that uses GoCV with your custom environment like this:
go run -tags customenv ./cmd/version/main.go
There is a Docker image with Alpine 3.7 that has been created by project contributor @denismakogon. You can find it located at https://github.com/denismakogon/gocv-alpine.