The script asks for the file that holds the preferences: which is copied to a new file, where it acts as the default instruction for the current & future runs.
PhotoScript/script/photo.sh at main · Linecutterx/PhotoScriptBash scripting for use of dcraw & Imagemagick in termux - for processing RAW photos - Linecutterx/PhotoScriptGitHubLinecutterx
First, you have to edit the script. Mainly
There are ways to try to compensate for the uneven exposure & that's what I've tried to build into the main script.
The process requires an image that has a gradient which will let us darken the central area of the image.
We've not mentioned exiftool yet, so I'll do that now & then we'll work through the concepts needed to turn a set of termux command line tools into a reasonably friendly system for processing a RAW photo