Package: opencvz-contrib-python
OpenCV on WheelsUnofficialpre-built OpenCV packages for Python.Strictly for Educational PurposeDo not RedistributeNot for Commercial UseInstallation and UsageIf you have previous/other manually installed (= not installed viapip) version of OpenCV installed (e.g. cv2 module in the root of Python's site-packages), remove it before installation to avoid conflicts.Select the correct package for your environment:There are four different packages and you shouldselect only one of them. Do not install multiple different packages in the same environment. There is no plugin architecture: all the packages use the same namespace (cv2). If you installed multiple different packages in the same environment, uninstall them all withpip uninstalland reinstall only one package.a.Packages for standard desktop environments (Windows, macOS, almost any GNU/Linux distribution)runpip install opencv-pythonif you need only main modulesrunpip install opencv-contrib-pythonif you need both main and contrib modules (check extra modules listing fromOpenCV documentation)b.Packages for server (headless) environmentsThese packages do not contain any GUI functionality. They are smaller and suitable for more restricted environments.runpip install opencv-python-headlessif you need only main modulesrunpip install opencv-contrib-python-headlessif you need both main and contrib modules (check extra modules listing fromOpenCV documentation)Import the package:import cv2All packages contain haarcascade files.cv2.data.haarcascadescan be used as a shortcut to the data folder. For example:cv2.CascadeClassifier(cv2.data.haarcascades + "haarcascade_frontalface_default.xml")ReadOpenCV documentationBefore opening a new issue, read the FAQ below and have a look at the other issues which are already open.Frequently Asked QuestionsQ: Do I need to install also OpenCV separately?A: No, the packages are special wheel binary packages and they already contain statically built OpenCV binaries.Q: Pip fails withCould not find a version that satisfies the requirement ...?A: Most likely the issue is related to too old pip and can be fixed by runningpip install --upgrade pip. Note that the wheel (especially manylinux) format does not currently support properly ARM architecture so there are no packages for ARM based platforms in PyPI. However,opencv-pythonpackages for Raspberry Pi can be found fromhttps://www.piwheels.org/.Q: Import fails on Windows:ImportError: DLL load failed: The specified module could not be found.?A: If the import fails on Windows, make sure you haveVisual C++ redistributable 2015installed. If you are using older Windows version than Windows 10 and latest system updates are not installed,Universal C Runtimemight be also required.Windows N and KN editions do not include Media Feature Pack which is required by OpenCV. If you are using Windows N or KN edition, please install alsoWindows Media Feature Pack.If the above does not help, check if you are using Anaconda. Old Anaconda versions have a bug which causes the error, seethis issuefor a manual fix.If you still encounter the error after you have checked all the previous solutions, downloadDependenciesand open thecv2.pyd(located usually atC:\Users\username\AppData\Local\Programs\Python\PythonXX\Lib\site-packages\cv2) file with it to debug missing DLL issues.Q: I have some other import errors?A: Make sure you have removed old manual installations of OpenCV Python bindings (cv2.so or cv2.pyd in site-packages).Q: Why the packages do not include non-free algorithms?A: Non-free algorithms such as SIFT and SURF are not included in these packages because they are patented and therefore cannot be distributed as built binaries. See this issue for more info:https://github.com/skvark/opencv-python/issues/126Q: Why the package and import are different (opencv-python vs. cv2)?A: It's easier for users to understandopencv-pythonthancv2and it makes it easier to find the package with search engines.cv2(old interface in old OpenCV versions was named ascv) is the name that OpenCV developers chose when they created the binding generators. This is kept as the import name to be consistent with different kind of tutorials around the internet. Changing the import name or behaviour would be also confusing to experienced users who are accustomed to theimport cv2.Documentation for opencv-pythonThe aim of this repository is to provide means to package each newOpenCV releasefor the most used Python versions and platforms.Build processThe project is structured like a normal Python package with a standardsetup.pyfile.
The build process for a single entry in the build matrices is as follows (see for exampleappveyor.ymlfile):In Linux and MacOS build: get OpenCV's optional C dependencies that we compile againstCheckout repository and submodulesOpenCV is included as submodule and the version is updated
manually by maintainers when a new OpenCV release has been madeContrib modules are also included as a submoduleFind OpenCV version from the sourcesInstall Python dependenciessetup.pyinstalls the dependencies itself, so you need to run it in an environment
where you have the rights to install modules with Pip for the running PythonBuild OpenCVtests are disabled, otherwise build time increases too muchthere are 4 build matrix entries for each build combination: with and without contrib modules, with and without GUI (headless)Linux builds run in manylinux Docker containers (CentOS 5)Rearrange OpenCV's build result, add our custom files and generate wheelLinux and macOS wheels are transformed with auditwheel and delocate, correspondinglyInstall the generated wheelTest that Python can import the library and run some sanity checksUse twine to upload the generated wheel to PyPI (only in release builds)Steps 1--5 are handled bysetup.py bdist_wheel.The build can be customized with environment variables.
In addition to any variables that OpenCV's build accepts, we recognize:ENABLE_CONTRIBandENABLE_HEADLESS. Set to1to build the contrib and/or headless versionCMAKE_ARGS. Additional arguments for OpenCV's CMake invocation. You can use this to make a custom build.LicensingOpencv-python package (scripts in this repository) is available under MIT license.OpenCV itself is available under3-clause BSD License.Third party package licenses are atLICENSE-3RD-PARTY.txt.All wheels ship withFFmpeglicensed under theLGPLv2.1.Linux and MacOS wheels ship withQt 4.8.7licensed under theLGPLv2.1.Versioningfind_version.pyscript searches for the version information from OpenCV sources and appends also a revision number specific to this repository to the version string.ReleasesA release is made and uploaded to PyPI when a new tag is pushed to master branch. These tags differentiate packages (this repo might have modifications but OpenCV version stays same) and should be incremented sequentially. In practice, release version numbers look like this:cv_major.cv_minor.cv_revision.package_revisione.g.3.1.0.0Development buildsEvery commit to the master branch of this repo will be built. Possible build artifacts use local version identifiers:cv_major.cv_minor.cv_revision+git_hash_of_this_repoe.g.3.1.0+14a8d39These artifacts can't be and will not be uploaded to PyPI.Manylinux wheelsLinux wheels are built usingmanylinux. These wheels should work out of the box for most of the distros (which use GNU C standard library) out there since they are built against an old version of glibc.The defaultmanylinuximages have been extended with some OpenCV dependencies. SeeDocker folderfor more info.Supported Python versionsPython 2.7 is the only supported version in 2.x series. Python 2.7 support will be dropped in the end of 2019.Python 3.x releases follow Numpy releases. For example Python 3.3 is no longer supported by Numpy so support for it has been dropped inopencv-python, too.Currently, builds for following Python versions are provided:2.73.43.53.63.7