PythInside for PixInsight

Welcome to PythInside!

PythInside runs Python scripts written for Siril (the free astronomical image processing program) on PixInsight images, and opens the possibility to write scripts in Python that run on PixInsight. The Siril scripts run as they are: nothing needs to be ported, converted or edited.

PythInside effectively gives us access to dozens of scripts, many of them not available for PixInsight: Statistical_Stretch, SCUNet_Denoise, NB_2_RG, the entire Svenesis and Veralux collections of scripts, NarrowbandNormalization, Galaxy_Annotations and over 60 more.

PythInside also unlocks the possibility to run Python scripts in general in PixInsight. All we need to do is write them as if they were for Siril, and our script will run in both, Siril and PixInsight.

Not only the entire arsenal of Python tools and libraries is at our disposal (numpy, scipy, OpenCV, onnx, and a long etc) while maintaining Siril and PixInsight compatibility, PythInside also adds a small set of python commands we can use to call PixInsight processes from Python. This, however, would make the scripts to break in Siril, but if we want to use Python with PixInsight processes, we can. Besides those commands, PythInside does not and will not offer any kind of API between PixInsight and Python. That would be a core feature that should only be carried by the PixInsight development team, in the event they decided to go for it.

PythInside does not offer support for Siril preprocessing scripts. Preprocessing is another functionality “core” to the program’s identity that we feel should be left alone. Besides, there is no reason to calibrate our frames with Siril scripts while using PixInsight. Just use PixInsight’s excellent tools!! And if we must calibrate using Siril, then the best thing would be to run Siril and do it there, if we must. What we can do is write Python scripts that use PixInsight’s calibration tools, for example.

Good to know: Some scripts generate an error the first time, during their package updates – this is normal, don’t report it: try closing and running it again. It should work. If you’re going to read anything, let that be the five bullets in Chapter 7 of PythInside’s Documentation. and the first few bullets in Chapter 7. Other scripts require downloading a ML model that could take some time to download, and a few commercial scripts ask for a license. All that is between you and the authors of the scripts.

PythInside requires Python 3.10 or later. Python 3.12 is currently the sweet spot. Everything else is handled by PythInside.

We should only run the scripts served by PythInside (Siril’s official repository), and scripts that we trust. 

• Run PixInsigth with PythInside already installed, and run PROCESS > DeepSkyColors > PythInside.
• Click “Set up…“. If Python is missing, install it (python.org) and start over.
• Click “Get Siril icons“.
• Open an image.
• Double click the GPU Manager script at the top, wait a while, and install the recommended ONNX Runtime and PyTorch (Siril users need to do this too).
• Close the GPU Manager.
• Double click any script. It will start to download some Python packages, just as it would do the same in Siril – once downloaded, this step is skipped. Some scripts may take a minute or more during their first run. Again, this is normal.
• Use the script. Changes are only applied when we exit the script. When a script offers a temporary “See it in Siril” or “Apply” button, the effect is applied, despite the image  is not being updated. Once we close the script, it will update.

Enjoy!