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Unofficial OpenCV packages for Python.

This package contains only the OpenCV core modules without the optional contrib modules.If you are looking for a version which includes OpenCV contrib modules, please installopencv-contrib-python instead.

The packages contain pre-compiled OpenCV binary with Python bindings.This enables super fast (usually < 10 seconds) OpenCV installation for Python.

If you need only OpenCV Python bindings, no separate OpenCV installation is required.

IMPORTANT NOTE

MacOS and Linux packages do not support video related functionality (not compiled with FFmpeg).

1. If you have previous/other version of OpenCV installed (e.g. cv2 module in the root of Python's site-packages), remove it before installation to avoid conflicts.

• To further avoid conflicts and to make development easier, Python'svirtual environments are highly recommended for development purposes.

2. If you have an existingopencv-contrib-python installation, runpip uninstall opencv-contrib-python
3. Install this package:

pip install opencv-python

4. Import the package:

import cv2

5. ReadOpenCV documentation
6. Before opening a new issue, read the FAQ below and have a look at the other issues which are already open.

Q: 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 does not find package ``opencv-python``?

A: The wheel package format and manylinux builds are pretty new things. Most likely the issue is related to too old pip and can be fixed by runningpip install --upgrade pip andpip install wheel.

Q: I need contrib modules?

A: Please installopencv-contrib-python instead. However, note that commercial usage might be restricted in some countries since the contrib modules contain some non-free/patented algorithms.

Q: Import fails on Windows to some DLL load error?

A: If the import fails on Windows, make sure you haveVisual C++ redistributable 2015 installed. If you are using older Windows version than Windows 10 and latest system updates are not installed,Universal C Runtime might be also required.

See alsothis issue if you are using Anaconda.

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 I can't open video files on GNU/Linux distribution X or on macOS?

A: OpenCV video I/O depends heavily on FFmpeg. Manylinux and macOS OpenCV binaries are not compiled against it.The purpose of these packages is to provide as easy as possible installation experience for OpenCV Python bindings and they should work directly out-of-the-box.Adding FFmpeg as an additional dependency without a "universal" FFmpeg build (e.g. LGPL licensed build like in the Windows wheels) the goal is considerably harder to achieve. This might change in the future.

The aim of this repository is to provide means to package each newOpenCV release for themost used Python versions and platforms.

At the same time it allows anyone to build a custom version of OpenCVfor any Python version: just fork this repo and modify the build filesand scripts to fit your needs.

The project is structured like a normal Python package with a standardsetup.py file. The build process for a single entry in the build matrices is as follows (see for exampleappveyor.yml file):

1. Checkout repository and submodules
   • OpenCV is included as submodule and the version is updatedmanually by maintainers when a new OpenCV release has been made
   • Contrib modules are also included as a submodule
2. Find OpenCV version from the sources
3. Install dependencies (numpy)
4. Build OpenCV
   • tests are disabled, otherwise build time increases too much
   • there are 2 build matrix entries for each build combination: with and without contrib modules
   • Linux builds run in manylinux Docker containers (CentOS 5)
5. Copy each.pyd/.so file to cv2 folder of this project andgenerate wheel
   • Linux and macOS wheels are checked with auditwheel and delocate
6. Install the generated wheel
7. Test that Python can import the library and run some sanity checks
8. Use twine to upload the generated wheel to PyPI (only in release builds)

Currently thefind_version.py file parses OpenCV version informationfrom the OpenCV sources. OpenCV depends on numpy, sosetup.py checksthe minimum required numpy version also with the help of pip.

Thecv2.pyd/.so file is normally copied to site-packages.To avoid polluting the root folder this package wrapsthe statically built binary into cv2 package and__init__.pyfile in the package handles the import logic correctly.

Since bothopencv-python andopencv-contrib-python use the same namespace explained above,it is highly recommended to uninstall the other package before switching from example fromopencv-python toopencv-contrib-python package.

Opencv-python package (scripts in this repository) is available underMIT license.

OpenCV itself is available under3-clause BSDLicense(LICENSE-3RD-PARTY.txt).

Windows wheels ship withFFmpeg licensed under theLGPLv2.1.

Linux and MacOS wheels ship withQt 4.8.7 licensed under theLGPLv2.1.

Currently thefind_version.py script searches for the versioninformation from OpenCV sources and appends also a revision numberspecific to this repository to the version string.

A release is made and uploaded to PyPI when a new tag is pushed tomaster branch. These tags differentiate packages (this repo might havemodifications but OpenCV version stays same) and should be incrementedsequentially. In practice, release version numbers look like this:

cv_major.cv_minor.cv_revision.package_revision e.g.3.1.0.0

Every commit to the master branch of this repo will be built. Possiblebuild artifacts use local version identifiers:

cv_major.cv_minor.cv_revision+git_hash_of_this_repo e.g.3.1.0+14a8d39

These artifacts can't be and will not be uploaded to PyPI.

Linux wheels are built usingmanylinux. Thesewheels should work out of the box for most of the distros(which use GNU C standard library) out there since they are builtagainst an old version of glibc.

Python 2.7 is the only supported version in 2.x series.Python 3.x releases follow Numpy releases, for examplePython 3.3 is no longer supported by Numpy so the supportfor it has been dropped inopencv-python too.

Currently, builds for following Python versions are provided:

• 2.7
• 3.4
• 3.5
• 3.6