opencv_config.md

Recommended OpenCV configuration

To build the demonstrations, the following build configuration of OpenCV is recommended. An example build command and a way to verify the configuration follow.

Build command

When all other required prerequisites are installed, the following cmake command can be used to build a minimum version of OpenCV:

cmake -D OPENCV_EXTRA_MODULES_PATH=../opencv_contrib-4.8.0/modules -D BUILD_LIST=calib3d,features2d,highgui,imgcodecs,imgproc,objdetect,sfm,stitching,videoio,viz -D WITH_1394=OFF -D WITH_GSTREAMER=OFF -D WITH_IPP=OFF -D WITH_OPENJPEG=OFF -D WITH_JASPER=OFF -D WITH_WEBP=OFF -D WITH_OPENEXR=OFF -D WITH_QT=ON -D WITH_TIFF=OFF -D WITH_OPENCL=OFF -D WITH_LAPACK=OFF -D BUILD_ITT=OFF -D WITH_PROTOBUF=OFF -D WITH_IMGCODEC_HDR=OFF -D WITH_IMGCODEC_SUNRASTER=OFF -D WITH_IMGCODEC_PFM=OFF -D WITH_QUIRC=OFF -D WITH_FLATBUFFERS=OFF -D BUILD_opencv_apps=OFF -D BUILD_DOCS=OFF -D BUILD_PACKAGE=OFF -D BUILD_JAVA=OFF -D OPENCV_GENERATE_PKGCONFIG=ON ../opencv-4.8.0/

The paths used in the above command are examples. The command is supposed to be called from within a newly created build directory inside the extracted OpenCV source code folder. The example paths can be used when the source code for OpenCV's contributed modules has been extracted to the same root directory as OpenCV's source code.

Verification

The output of the cmake call (see above for an example) must include the following lines (in this order) so that the selected OpenCV configuration can be used to build all demonstrations:

--   OpenCV modules:
--     To be built:                 calib3d core features2d flann highgui imgcodecs imgproc objdetect sfm stitching videoio viz xfeatures2d

Additional modules may be listed.

--   GUI: 
--     QT:                          YES (ver 5.15.2)
--       QT OpenGL support:         NO
[...]
--     VTK support:                 YES (ver 9.0.1)

The listed versions may be different.

--   Media I/O: 
--     ZLib:                        /usr/lib/x86_64-linux-gnu/libz.so (ver 1.2.11)
--     JPEG:                        /usr/lib/x86_64-linux-gnu/libjpeg.so (ver 62)
--     PNG:                         /usr/lib/x86_64-linux-gnu/libpng.so (ver 1.6.37)
[...]
--     PXM:                         YES

The listed versions may be different.

--   Video I/O:
[...]
--     v4l/v4l2:                    YES (linux/videodev2.h)

Note: V4L support is only needed for accessing webcams and similar devices in those demonstrations which support this. All demonstrations are fully functional with image or video input only, i.e., without webcams. Thus, V4L support is not required.

--   Other third-party libraries:
--     VA:                          NO
--     Eigen:                       YES (ver 3.3.9)
[...]
--     Protobuf:                    build (3.19.1)

The listed versions may be different.

--   Install to:                    /usr/local

The installation path may differ as long as sudo ldconfig is run after the installation and the path is known to ldconfig.