Found a #Linux program I like. It's called #geeqie
https://www.geeqie.org/
It does a variety of things to images. What I've been using it for it to find duplicate/similar images. It's not as good as #Visipics (https://visipics.info) as each has to be deleted seperatly, but it's the best I've found so far.
First I tried to run Visipics with Proton. It works, but it still shows a Windows file system, which isn't helping.
At some time between July and December 2023 the web site for VisiPics (a Windows software that finds duplicate images, last updated in, like, 2015) was moved from a Mediawiki to something else, the download link is now a "safe download provided by mega.nz" (instead of Fosshub), and there's also a generic Paypal donation address.
It seems quite improbable that this thing is still under control of the original author (I didn't try to check what's in the file provided via mega.nz).
Last snapshot of the old page on a.o was https://web.archive.org/web/20230730044515/http://www.visipics.info/index.php?title=Main_Page
Dawn TΓ₯ke π 
Alexander Bochmann