Verified the thumbnail-cacher script is working perfectly in Mate/Caja in addition to Openbox/PcmanFM.

For PcmanFM it's a great band-aid, makes using it so much faster running this one-time on startup. But it's also useful in Mate if you run a cleanup via Bleachbit or other means that deleted the old thumbnail cache either manually or with a cron job, running this script will generate new thumbnails and cache them, sweeping only your home folder.

Pulled down the full script for now, takes a lot of ram for big .xcf's and multiples of them.

Rule-of-thumb that's been helping me downsize over the years, is this:

Never look in the repo first for packages to solve your problem, when it might be solved using resources already onboard and a tiny shell-script.

Yad + dash = your friend!

Got it worked out, now i've got the thumbnailer script doing .xcf's, using gimp in the background was really the only way, so it does take some resources and some extra time on the .xcf's...seems like there ought to be a faster lighter way, but it does have to do a lot. It's not bad at all if there's just a few, and you won't even notice it most likely when the script runs on startup. Takes about an extra 20 seconds to do a few, everything else is super-quick.

First run if you have a lot of un-thumbnailed .xcf's might take a while, but in every day use even a few hours of gimp'ing will only leave me with a few new .xcf files, most of the new files generated in a session like that will be .png's and they thumbnail super fast.

No love for Parcellite? I have used it for years, works fine for my needs. Bonus: i've never had to configure it, drops into Mate panel automatically no config issues. Works great in Tint2 as well, just need to add it to Openbox autostart file.

And now the fixed version has been pushed into trixie, I need to double-check and make sure they are in excalibur too, and it will be time to cook up another tasty testing iso.

Really starting to appreciate .xsession-errors, it's helped me to fix a ton of small bugs, many that I didn't know existed.

But with Mate in general, I think it just likes to complain. Even in the current version I get a ton of errors from mate-session, mate-session-check-accelerated, mate-settings-daemon, marco, caja etc. all complaining about theme-parsing errors in the gtk-css.

In Openbox I get zero complaints about anything theme related. And I can't seem to narrow down what Mate has an issue with anywhere in the css, I have checked it through and through and updated where necessary and ran it through automated checkers as well, go figure.

Maybe the new version fixes some of that too, will find out hopefully by later today!

The webp thumbnailer actually just uses the gdk-pixbuf-thumbnailer as does the librsvg thumbnailer, it's all in the gdk-pixbuf these days for most common image formats except for heif/heic/avif.

I'd thought about using Imagemagick first off, but for my script python3-pil worked great.

Also I wasn't sure if Imagemagick can create an actual linked thumbnail per spec, or just make some smaller copies of the image? i.e. filename per XDG spec (MD5 of file URI), metadata etc.

That's the beauty of using the onboard thumbnailers, makes for an easy script to write for what I wanted. Maybe i'm just being thick-headed and lazy, lol.

And as you mentioned, layers is an issue. I've seen a bunch of examples of IM thumbs for .xcf that turned out to be a blank black or white square because that's the first layer on what most projects start out with. The thumbs kicked out by Gimp however all look perfect, a small background thumbnailer using gimp would likely be the best bet.

4-22-2025

New 5.03 Vuu-do Openbox Z's uploaded

Tons of tiny fixes, the theme change left some things undone. Added a lot of bug
and error fixes plus updated functionality quite a bit, support is extended for
newer image formats, and the biggest change is the addition of the thumbnail-cacher
script which assists PcmanFM in creating and caching thumbnails properly. This has
greatly speeded up image-heavy folder loading. Check the menu for the entry to
update the cache during sesssion if you add a lot of images or video.

From the comments in the script:

This script creates and caches thumbnails of image/video files.
It sweeps the users home folder only (excluding hidden files), checking for
image and video files and if they have a thumbnail cached, if not then it
creates new thumbnails and adds them to the thumbnail cache in ~/.cache.
It's set to only thumbnail files 100 kb and larger. It's intended use is for PcmanFM,
to assist in generating a proper thumbnail cache. It can be set to run once at boot/login,
and/or used as a menu entry to create an updated cache file at any time.

PcmanFM will continue to generate the cached thumbnails for images larger than
4.2 mb on-the-fly as you add them, run this after you add smaller images and it will add
them to the cache as well. At 4.2 mb or higher the thumbnail setting in PcmanFM works,
any lower and you start losing thumbnails randomly for some reason, this just catches
the smaller stuff albeit not on-the-fly which would be optimal, but image-heavy folder
loads are way faster when the images are already thumbnailed & cached.

Script located in /usr/local/bin if you want to edit thumbnail size or add thumbnailers/formats.
Atril has a thumbnailer which lets you add text and pdf thumbnails but I don't see a point in it.
I may try to add .xcf and maybe another video format to see what happens, but as of right now
it supports most major image formats, and .mpg, .mpeg, .mp4 and .mkv video formats. It also
works on the newer image formats that I added support for in Vuu-do not long ago, .avif, heic, heif, and .webp.

Finally got around to working on a workaround for the bug I posted here https://bugs.debian.org/cgi-bin/bugrepo … ug=1100053

Doesn't seem like it's going to be fixed anytime soon as I have no replies. Got a workaround running using a script that creates cached thumbnails under 4.2 mb and applies them via autostart for users home. Checks for files at login, creates if there isn't one, updates if needed.
Pcmanfm runs nice and fast with this applied, initial and subsequent visits to file-manager with any images open waaaaay faster.

Still need some fine-tuning, but should have it done and new isos up soon!

ETA: well that was harder than I thought, almost there though....

I do love me some Imagemagick, but I use Scrot for screenshots, super lightweight yet very configurable.

4-16-2025: Updated Vuu-do ob-max-z uploaded.
4-18-2025: Mini-z now up as well.

Major updates to artwork, all new original stuff, wallpaper & login background,
grub splash, lock screen, user avatar etc. Lots of package updates including a new
kernel and security updates. New menu entry to configure keyboard and much nicer
gui for that and also for changing tzdata via right-click on the panel clock, and
many other small tweaks. Ob-max is first up, will get a new mini up here soon.

Lots of changes in this one, and minor tweaks galore, finally got around to updating
the conkyrc to the newer lua format, fixed an icon issue and stomped some more
tiny bugs. Added the keyboard-config menu entry, wrote a tiny script for it as it
didn't have a confirmation dialog for when you get done. Thanks to fsmithred once
again as I snagged some code from the pre-install scripts in Refracta-Installer to
make the keyboard and tzdata functions much prettier and easier to deal with.

Pushed a new update to the Vuu-do mate-mini iso, new kernel plus security and regular updates and some other stuff.
Working on the OB's now, some significant improvements in those coming up in addition to updates.

Symptoms sound exactly like what happens when ram gets maxed out and starts spilling over into swap, Devuan's pretty robust for me so it takes a lot to make it happen, like multiple browser tabs + starting some other programs. Like you OP I only have 4 gigs of ram.

Conky display is helpful, I have mine set to display ram and swap usage in addition to other things, and the few times i've had this happen to me it's always that ram got maxed out and there will now be content in the swap partition.

I've got an old 2005 machine that runs, but it only has 1 gig of ram, so it's super-easy to make it happen, maybe 4 browser tabs and it gets sloooooooooowww....