How to generate thumbnails of GIMP .xcf files in your file-manager

greenjeans · 2025-04-23 20:03:21

Well long story short after much research, apparently for a couple of years now .xcf thumbnailers have disappeared, likely with the rollout of gimp 2.10 and some changes they made to the format, so all you get when you save an .xcf is the wilbur icon. Gdk-pixbuf does not support it and other programs to do so are abandoned.

So basically the only thing that can thumbnail them is gimp itself, but in 2.10 it doesn't do so automatically when you create a new file and save it as an .xcf.

To get it to do so, open gimp, and at the top choose File >>Open

This will open gimp's file-browser, navigate to the folder with your .xcf's. There's a side-pane for previews in that file-browser, as you scroll to your .xcf's they will still show the wilbur icon but there is a message in that preview pane to "click for preview", click that and gimp immediately generates a thumbnail that gets stored, and when you go back to your file-manager the .xcf will now show as a proper thumbnail of the image.

If anyone has information to the contrary, I and a lot of other folks would love to hear it!

A dirty little script would work if it didn't involve firing up the entirety of gimp, been working on a thumbnailer project the last few days and it works great, but it uses the native thumbnailers onboard like gdk-pixbuf and ffmpeg thumbnailers to do the work so it's very smooth and fast.

EDX-0 · 2025-04-23 21:12:15

well taking inspiration from https://docs.xfce.org/xfce/tumbler/available_plugins with the webp thumbnailer i decided to check and turns out that yes, this once again imagemagick comes to the rescue as it can properly understand the xcf format.

just one small caveat, xcf files are multi-layer and while imagemagick can understand multi-frame, multi-page and multi-layer just fine however a simple convert image.xcf image.png will produce

image-0.png
image-1.png
...
image-n.png

for every layer of the xcf file, so a dirty solution if your xcf files got low layer counts is to use /usr/bin/convert "$1[0]" -thumbnail "$2" "$3" to hardcode layer 0, otherwise you got to extract every single layer and compose them in the correct position.

greenjeans · 2025-04-23 22:29:18

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.

Last edited by greenjeans (2025-04-23 22:39:42)

greenjeans · Today 00:05:16

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.

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#1 2025-04-23 20:03:21

How to generate thumbnails of GIMP .xcf files in your file-manager

#2 2025-04-23 21:12:15

Re: How to generate thumbnails of GIMP .xcf files in your file-manager

#3 2025-04-23 22:29:18

Re: How to generate thumbnails of GIMP .xcf files in your file-manager

#4 Today 00:05:16

Re: How to generate thumbnails of GIMP .xcf files in your file-manager

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