Wrapper package for OpenCV python bindings.
Project description
OpenCV on wheels
Unofficial OpenCV packages for Python.
The aim of this repository is to provide means to package each new OpenCV release for the most used Python versions and platforms.
At the same time it allows anyone to build a custom version of OpenCV for any Python version: just fork this repo and modify the build files and scripts to fit your needs.
Installation and Usage
To install this package:
pip install opencv-python
To import the package:
import cv2
Build process
The project is structured like a normal Python package with a standard setup.py file. The build process is as follows (see for example appveyor.yml file):
Checkout repository and submodules
OpenCV is included as submodule and the version is updated manually by maintainers when a new OpenCV release has been made
Find OpenCV version from the sources
Upgrade pip and install numpy for each Python version
Build OpenCV
tests are disabled, otherwise build time increases too much
Copy each .pyd/.so file to cv2 folder of this project and generate wheel
Install the generated wheels for each Python version
Test that the Python versions can import them
Use twine to upload all wheels to PyPI
Currently the find_version.py file parses OpenCV version information from the OpenCV sources. OpenCV depends on numpy, so setup.py checks the numpy version also with the help of pip.
The cv2.pyd file for example on Windows is normally copied to site-packages. To avoid polluting the root folder the __init__.py file in cv2 folder handles the import logic correctly by importing the actual .pyd module and replacing the imported cv2 package in sys.modudes with the cv2 module to retain backward compatibility.
Licensing
Opencv-python package (scripts in this repository) is available under MIT license.
OpenCV itself is available under 3-clause BSD License (LICENSE-3RD-PARTY.txt).
Windows wheels ship with FFmpeg licensed under the LGPLv2.1.
Versioning
Currently the find_version.py script searches for the version information from OpenCV sources and appends also a revision number specific to this repository to the version string.
Releases
A 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_revision e.g. 3.1.0.0
Development builds
Every 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_repo e.g. 3.1.0+14a8d39
These artifacts can’t be and will not be uploaded to PyPI.
Manylinux wheels
Linux wheels are built using manylinux. 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.
Supported Python versions
Windows:
There’s a build time limitation (AppVeyor open source builds may take max 1 hour) which restricts the supported Python versions to two (note: the performance is better nowadays, for example py33 and py34 could be added to appveyor.yml). As Python’s 2.x releases are slowly approaching legacy state, 2.7.x releases will be the only supported Python 2 versions on Windows. On Python 3 side, builds will be run only for the latest release.
However, if you wan’t to get some other versions, just fork this repo and change the dependencies.
Linux
Manylinux wheels are built for all the Python versions which are supported by the manylinux containers.
OS X
Currently built for Python 2.7, 3.4 and 3.5.
