Contributing to CbM

Please take a moment to review this document in order to make the contribution process easy and effective for everyone involved.

Following these guidelines helps to communicate that you respect the time of the developers managing and developing this open source project. In return, they should reciprocate that respect in addressing your issue or assessing patches and features.

Using the issue tracker

The issue tracker is the preferred channel for submitting pull requests and bug reports, but please do not use the issue tracker for personal support requests. Consider one of the following alternatives instead:

Pull requests

Good pull requests - patches, improvements, new features - are helpful. They should remain focused in scope and avoid containing unrelated commits.

Please ask first before embarking on any significant pull request (e.g. implementing features, refactoring code), otherwise you risk spending a lot of time working on something that the project’s developers might not want to merge into the project. Read the tutorial on writing new CbM functions if you want to contribute a brand new feature.

If you are new to Git, GitHub, or contributing to an open-source project, you may want to consult our guide on preparing and submitting a pull request or check our list of useful related documentations.

Bug reports

A bug is a demonstrable problem that is caused by the code in the repository. Good bug reports are extremely helpful - thank you!

Guidelines for bug reports:

  1. Check if the issue has been reported — use GitHub issue search and mailing list archive search.

  2. Check if the issue has been fixed — try to reproduce it using the latest main branch in the repository.

  3. Isolate the problem — ideally create a reduced test case.

A good bug report shouldn’t leave others needing to chase you up for more information. Please try to be as detailed as possible in your report. What is your environment? What steps will reproduce the issue? What would you expect to be the outcome? All these details will help people to fix any potential bugs.


Short and descriptive example bug report title

A summary of the issue and the OS environment in which it occurs. If suitable, include the steps required to reproduce the bug.

  1. This is the first step

  2. This is the second step

  3. Further steps, etc.

Any other information you want to share that is relevant to the issue being reported. This might include the lines of code that you have identified as causing the bug, and potential solutions (and your opinions on their merits).


CbM is 3-Clause BSD licensed, and by submitting a patch, you agree to allow Open Perception, Inc. to license your work under the terms of the BSD 3-Clause License. The link of the license should be inserted as a comment on top of each .py file e.g.:

# This file is part of CbM (
# Copyright : 2021 European Commission, Joint Research Centre
# License   : 3-Clause BSD

Note that if the academic institution or company you are affiliated with does not allow to give up the rights, you should contact us for further details.