Method for drawing masks on top of data

[takluyver]

There's an example of making masks programmatically, but on many occasions it's easier to select parts of an image visually.

I don't want to build extensive GUI code into EXtra-geom - full fledged applications should be built as separate packages on top of it. But I think we can do something simple with matplotlib events, which can also serve as an example for building bigger applications. Matplotlib events also have the advantage that the same code can work in the notebook and a script which can open a separate window.

[daviddoji]

That would be awesome!
This will help many people, including myself, that use external software to draw masks, e.g., the GUI in pyFAI-calib2

[takluyver]

I made a start on it in a notebook: https://max-jhub.desy.de/user-redirect/notebooks/GPFS/exfel/exp/SCS/202002/p002530/usr/kluyvert/Making%20masks.ipynb . Do you want to have a play with that, with a view to integrating the functionality in EXtra-geom.

It will probably be a bit clumsy and limited compared to dedicated interactive applications - I don't want to get properly into GUI code in EXtra-geom. I'm thinking of putting it in almost like a proof of concept.