Batch processing of photos on post-editing

[PixLab]

FWIW, when I have big batches processing, I use XnConvert, (xnconvert is also part of xnview) and xnconvert can be in your distro software center, if not > https://www.xnview.com/en/xnconvert/ , they have a .deb and a targz.
It has visualization, but if you change one setting it will apply to the thousands of picture or the whole directory you dropped in it..

For what is worth