easy_opencv

This library provides an easy way to build OpenCV from source and statically link it into your project. You can also choose which of the parts of OpenCV you want to include / exclude from your build.

• Including
• Choosing which parts of OpenCV you want to build
• For maintainers
  • Running the tests
  • Building the tests for Linux

Including

To add this library to your project, simply add these lines to your CMakeLists.txt:

# Download the library
include(FetchContent)
FetchContent_Declare(
    easy_opencv
    GIT_REPOSITORY https://github.com/CoolLibs/easy_opencv
    GIT_TAG aa8dbf985f5cee8fe7c23308764413814a0d3217
)
FetchContent_MakeAvailable(easy_opencv)

# Link the library into your project
target_link_libraries(${PROJECT_NAME} PRIVATE easy_opencv::easy_opencv)

You will then have access to OpenCV and be able to use this test program for example:

#include <iostream>
#include <opencv2/opencv.hpp>

auto main() -> int
{
    auto video_capture = cv::VideoCapture{0};
    if (!video_capture.isOpened())
    {
        std::cout << "Cannot access webcam.\n";
        return -1;
    }

    auto image = cv::Mat{};
    while (cv::waitKey(1) != 27 /*ESCAPE*/)
    {
        video_capture >> image;
        cv::imshow("Hello OpenCV - Press ESCAPE to close me", image);
    }
}

Choosing which parts of OpenCV you want to build

To select which parts of OpenCV you want to build, we recommend creating an opencv_build_options.cmake file and including it in your CMakeLists.txt before including easy_opencv:

# Choose which parts of OpenCV to build
include("opencv_build_options.cmake")

# Download the library
include(FetchContent)
FetchContent_Declare(
    easy_opencv
    GIT_REPOSITORY https://github.com/CoolLibs/easy_opencv
    GIT_TAG aa8dbf985f5cee8fe7c23308764413814a0d3217
)
FetchContent_MakeAvailable(easy_opencv)

# Link the library into your project
target_link_libraries(${PROJECT_NAME} PRIVATE easy_opencv::easy_opencv)

This opencv_build_options.cmake file would look something like this, and you can turn the different OpenCV options ON or OFF:

#opencv_build_options.cmake

# Choose which external libraries to link into OpenCV
set(WITH_1394 OFF CACHE BOOL "" FORCE)
set(WITH_ADE OFF CACHE BOOL "" FORCE)
set(WITH_ARITH_DEC OFF CACHE BOOL "" FORCE)
set(WITH_AVIF OFF CACHE BOOL "" FORCE)
set(WITH_CANN OFF CACHE BOOL "" FORCE)
set(WITH_CLP OFF CACHE BOOL "" FORCE)
set(WITH_CUDA OFF CACHE BOOL "" FORCE)
set(WITH_DIRECTX OFF CACHE BOOL "" FORCE)

if(WIN32)
    set(WITH_DSHOW ON CACHE BOOL "" FORCE)
else()
    set(WITH_DSHOW OFF CACHE BOOL "" FORCE)
endif()

set(WITH_EIGEN OFF CACHE BOOL "" FORCE)
set(WITH_FFMPEG OFF CACHE BOOL "" FORCE)
set(WITH_FLATBUFFERS OFF CACHE BOOL "" FORCE)
set(WITH_FREETYPE OFF CACHE BOOL "" FORCE)
set(WITH_GDAL OFF CACHE BOOL "" FORCE)
set(WITH_GDCM OFF CACHE BOOL "" FORCE)
set(WITH_GSTREAMER OFF CACHE BOOL "" FORCE)

if(LINUX)
    set(WITH_GTK ON CACHE BOOL "" FORCE)
else()
    set(WITH_GTK OFF CACHE BOOL "" FORCE)
endif()

set(WITH_GTK_2_X OFF CACHE BOOL "" FORCE)
set(WITH_HALIDE OFF CACHE BOOL "" FORCE)
set(WITH_HPX OFF CACHE BOOL "" FORCE)
set(WITH_IMGCODEC_HDR OFF CACHE BOOL "" FORCE)
set(WITH_IMGCODEC_PFM OFF CACHE BOOL "" FORCE)
set(WITH_IMGCODEC_PXM OFF CACHE BOOL "" FORCE)
set(WITH_IMGCODEC_SUNRASTER OFF CACHE BOOL "" FORCE)
set(WITH_IPP OFF CACHE BOOL "" FORCE)
set(WITH_ITT OFF CACHE BOOL "" FORCE)
set(WITH_JASPER OFF CACHE BOOL "" FORCE)
set(WITH_JPEG OFF CACHE BOOL "" FORCE)
set(WITH_LAPACK OFF CACHE BOOL "" FORCE)
set(WITH_LIBREALSENSE OFF CACHE BOOL "" FORCE)
set(WITH_MFX OFF CACHE BOOL "" FORCE)
set(WITH_MSMF OFF CACHE BOOL "" FORCE)
set(WITH_MSMF_DXVA OFF CACHE BOOL "" FORCE)
set(WITH_OAK OFF CACHE BOOL "" FORCE)
set(WITH_OBSENSOR OFF CACHE BOOL "" FORCE)
set(WITH_OPENCL OFF CACHE BOOL "" FORCE)
set(WITH_OPENCLAMDBLAS OFF CACHE BOOL "" FORCE)
set(WITH_OPENCLAMDFFT OFF CACHE BOOL "" FORCE)
set(WITH_OPENCL_D3D11_NV OFF CACHE BOOL "" FORCE)
set(WITH_OPENCL_SVM OFF CACHE BOOL "" FORCE)
set(WITH_OPENEXR OFF CACHE BOOL "" FORCE)
set(WITH_OPENGL OFF CACHE BOOL "" FORCE)
set(WITH_OPENJPEG OFF CACHE BOOL "" FORCE)
set(WITH_OPENMP OFF CACHE BOOL "" FORCE)
set(WITH_OPENNI OFF CACHE BOOL "" FORCE)
set(WITH_OPENNI2 OFF CACHE BOOL "" FORCE)
set(WITH_OPENVINO OFF CACHE BOOL "" FORCE)
set(WITH_OPENVX OFF CACHE BOOL "" FORCE)
set(WITH_PLAIDML OFF CACHE BOOL "" FORCE)
set(WITH_PNG OFF CACHE BOOL "" FORCE)
set(WITH_PROTOBUF OFF CACHE BOOL "" FORCE)
set(WITH_PTHREADS_PF OFF CACHE BOOL "" FORCE)
set(WITH_PVAPI OFF CACHE BOOL "" FORCE)
set(WITH_QT OFF CACHE BOOL "" FORCE)
set(WITH_QUIRC OFF CACHE BOOL "" FORCE)
set(WITH_SPNG OFF CACHE BOOL "" FORCE)
set(WITH_TBB OFF CACHE BOOL "" FORCE)
set(WITH_TIFF OFF CACHE BOOL "" FORCE)
set(WITH_TIMVX OFF CACHE BOOL "" FORCE)
set(WITH_UEYE OFF CACHE BOOL "" FORCE)
set(WITH_VTK OFF CACHE BOOL "" FORCE)
set(WITH_VULKAN OFF CACHE BOOL "" FORCE)
set(WITH_WEBNN OFF CACHE BOOL "" FORCE)
set(WITH_WEBP OFF CACHE BOOL "" FORCE)

if(WIN32)
    set(WITH_WIN32UI ON CACHE BOOL "" FORCE)
else()
    set(WITH_WIN32UI OFF CACHE BOOL "" FORCE)
endif()

set(WITH_XIMEA OFF CACHE BOOL "" FORCE)

# Choose which parts of OpenCV to build
set(BUILD_JAVA OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_apps OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_calib3d OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_dnn OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_features2d OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_flann OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_gapi OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_highgui ON CACHE BOOL "" FORCE)
set(BUILD_opencv_imgcodecs ON CACHE BOOL "" FORCE)
set(BUILD_opencv_imgproc ON CACHE BOOL "" FORCE)
set(BUILD_opencv_java_bindings_generator OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_js OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_js_bindings_generator OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_ml OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_objc_bindings_generator OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_objdetect OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_photo OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_python_bindings_generator OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_python_tests OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_stitching OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_ts OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_video OFF CACHE BOOL "" FORCE)
set(BUILD_opencv_videoio ON CACHE BOOL "" FORCE)

# Choose if we want to skip Python support
set(OPENCV_PYTHON_SKIP_DETECTION ON CACHE BOOL "" FORCE)

You can find an example of such a setup in our tests folder.

For maintainers

Running the tests

Simply use "tests/CMakeLists.txt" to generate a project, then run it.
If you are using VSCode and the CMake extension, this project already contains a .vscode/settings.json that will use the right CMakeLists.txt automatically.

Building the tests for Linux

You might need to install GTK (sudo apt-get install libgtk-3-dev).