Information for developers and contributors

OpenPiv need developers to improve further. Your support, code and contribution is very welcome and we are grateful you can provide some. Please send us an email to to get started, or for any kind of information.

We use git for development version control, and we have a main repository on github.

Development workflow

This is absolutely not a comprehensive guide of git development, and it is only an indication of our workflow.

  1. Download and install git. Instruction can be found here.

  2. Set up a github account.

  3. Clone OpenPiv repository using:

    git clone
  4. create a branch new_feature where you implement your new feature.

  5. Fix, change, implement, document code, …

  6. From time to time fetch and merge your master branch with that of the main repository.

  7. Be sure that everything is ok and works in your branch.

  8. Merge your master branch with your new_feature branch.

  9. Be sure that everything is now ok and works in you master branch.

  10. Send a pull request.

  11. Create another branch for a new feature.

Which language can I use?

As a general rule, we use Python where it does not make any difference with code speed. In those situations where Python speed is the bottleneck, we have some possibilities, depending on your skills and background. If something has to be written from scratch use the first language from the following which you are confortable with: Cython, C, C++, FORTRAN. If you have existing, debugged, tested code that you would like to share, then no problem. We accept it, whichever language may be written in!

Things OpenPIV currently needs, (in order of importance)

  • Good documentation (in progress)
  • The implementation of advanced processing algorithms (in progress)
  • Flow field filtering and validation functions
  • Cython wrappers for C/C++ codes.
  • A good graphical user interface (in progress)

How to test all the notebooks::

conda create -n openpiv conda activate openpiv conda install -c conda-forge openpiv conda install ipykernel python -m ipykernel install –user –name openpiv –display-name=”openpiv” jupyter nbconvert –to html –ExecutePreprocessor.kernel_name=openpiv –execute *.ipynb

Then open the openpiv/examples/notebooks and check the HTML files. If one of those will fail, the error message will be in the command shell

If you need to install cv2::

conda install -c conda-forge opencv