DisplayCAL Python 3 Project

This project intended to modernize the DisplayCAL code including Python 3 support.

Florian Höch, the original developer, did an incredible job of creating and maintaining DisplayCAL for all these years. But, it seems that, during the pandemic, very understandably, he lost his passion to the project. Now, it is time for us, the DisplayCAL users, to contribute back to this great tool.

This project is based on the HEAD of the Sourceforge version, which has 5 extra commits that Florian has created after the 3.8.9.3 release on 14 Jan 2020.

Status Update (30 April 2022)

DisplayCAL is in PyPI now (yay!).

Here is a screenshots showing the tool working with Python 3.9:

Currently, DisplayCAL is working with Python 3.9.7 + wxPython 4.1.1.

Here is a list of things that is working:

• The UI and general functionality.
• Calibration + Characterization (Profiling).
• Installing the created ICC profile.
• Installing the created ICC profiles as root.
• Profile info window is now fully working (on some systems we still have an issue related to default values #67).
• Measurement report creation.
• Creating, displaying and uploading Colorimeter Corrections.
• Measuring and reporting display uniformity.
• Creating charts with Test Chart Editor and creating diagnostic 3d data.
• Creating 3D LUTs.
• and a lot of other stuff is working properly.

What is not working (yet)

• There are tons of bytes/str related issues, getting fixed very quickly but more tests are needed.
• Please create issues

How to install

Currently, there is no RPM, DEB, APP or MSI packages. To test the code you can either run it directly from the source or install it as a sdist package. To do this:

Prequisties:

• Assorted C/C++ builder tools
• dbus-1
• glib 2.0
• gtkd 3
• libxxf86vm
• pkg-config

Please install these from your package manager.

# Brew on Macs
brew install pkg-config dbus glib gtk+3

# Debian installs
apt-get install build-essential dbus libglib2.0-dev pkg-config libgtkd-3-dev libxxf86vm-dev

Then pull the source and create a virtual environment:

git clone https://github.com/eoyilmaz/displaycal-py3
python -m venv ./displaycal_venv
source ./displaycal_venv/bin/activate  # Windows: .\displaycal_venv\Scripts\activate.bat
cd ./displaycal-py3/
pip install -r requirements.txt
python -m build
pip install dist/DisplayCAL-3.9.0-*.whl

This should install DisplayCAL. To run the UI:

displaycal

ATTENTION!

Previously the --install-data=$HOME/.local option has to be used with the setup.py script in order to let the DisplayCAL to find the required data files. But it is not needed anymore, and it is a good idea to delete the DisplayCAL* files and folders from the site-packages folder of your python interpreter if you used that option in a previous version of DisplayCAL-py3.

Road Map

Some ideas on where to focus on future development:

• Add DisplayCAL to PyPI (#83).
• Try to move the UI to Qt. This is a big ticket. The motivation behind that is that I'm much more experienced with Qt. In fact, I have zero experience with wxPython.
• Make the code fully compliant with PEP8 with the modification of hard wrapping the code at 88 characters instead of 80 characters. This also means a lot of class and method/function names will be changed.
• Create unit tests with Pytest and reach to 100% code coverage. The 3.8.9.3 version of DisplayCAL is around 120k lines of Python code (other languages are not included) and there are no tests (or the repository I adapted doesn't contain any tests). This is a nightmare and super hard to maintain. This is an ongoing work, with the latest commits we have over 150 tests (which is super low for, should be thousands) and the code coverage is around 25% (again this is super low, should be over 99%).
• Maybe I'm not experienced enough, and I'm wrong on saying this, but I don't see the motivation behind having a C-Extension for EDID, XRandr etc. stuff. It should be possible to cover all the functionality of this extension and stay purely in Python. It is super hard to debug (for me at least) and super hard to maintain (again, for me).
• Replace the wexpect.py with the latest release of Pexpect. I'm not very familiar with this module, and there is no comment in the code on why we have a wexpect.py instead of using the PyPI version of Pexpect.
• Replace os.path related stuff with pathlib.
• Organize the module structure, move UI related stuff in to ui module etc., move non-source files into their own folders.
• Update the Remaining time calculation during profiling to estimate the time by also considering the luminance of the remaining patches to have a better estimation. Because, patches with higher luminance values are measured quickly than patches with lower luminance values.
• Replace the DisplayCAL.ordereddict.OrderedDict with the pure Python dict which is ordered after Python 3.6. (Done!)

Issues related to these ideas have been created. If you have a feature request, you can create more issues or share your comment on the already created issues or create merge requests that are fixing little or big things.

Because there are very little automated tests, I need the code to be tested constantly. Please help me with that.

Have fun!