Image stacking specifically for ice-crystal halo photographs.
Halostack aligns a series of exposures on a feature you pick — usually the Sun behind a blocker — combines them into one or more stacks, and applies enhancements that make faint halos visible.
Six exposures aligned on the Sun and combined, with the background gradient removed and an unsharp mask applied. The green box is the alignment reference, the orange one the area it is searched for in each frame.
pip install halostack # add [raw] for camera raw files
Runs on Windows, macOS and Linux with Python 3.12 or newer. Every dependency
ships as a binary wheel, so there is nothing to compile. On Linux the window
additionally needs libxcb-cursor from your distribution (sudo apt install libxcb-cursor0 on Debian and Ubuntu); Halostack says so if it is missing, and
the command line does not need it.
On Windows you can skip Python entirely: a standalone halostack.exe, with
both interfaces in it, is attached to each
release.
halostack # opens the window
halostack -a average_stack.png *.jpg # command line, straight to work
An option means "do this now"; nothing but filenames opens the window with them loaded. In either interface you mark the alignment reference on the first frame, and the area to search for it in the remaining frames.
The documentation is available at http://halostack.readthedocs.org/