sudo apt-get install gnome-raw-thumbnailer ufraw-batch
Try now if everything works, and your thumbnails show up. If not, try the following part.
In case the default config does not work for you, try this:
Edit the file /usr/share/thumbnailers/raw.thumbnailer
as root and insert the following content:
[Thumbnailer Entry]
TryExec=ufraw-batch
Exec=ufraw-batch --silent --size %s --out-type=png --noexif --output=%o --overwrite --embedded-image %i
MimeType=image/x-canon-cr2;image/x-canon-crw;image/x-minolta-mrw;image/x-nikon-nef;image/x-pentax-pef;image/x-panasonic-raw2;image/x-samsung-srw;image/x-olympus-orf;
Check if the mime type of your RAW images in in the MimeType
list.
After that, stop nautlius and clear the thumbnail caches:
nautilus -q
rm -rf .cache/thumbnails/* .thumbnails/*
@hronellenfitsch, @xtermi2: Neither ufraw-batch nor gnome-raw-thumbnailer are available in 19.10, but I got raw thumbnails working by editing the gdk-pixbuf thumbnailer's MIME types. Open up
/usr/share/thumbnailers/gdk-pixbuf-thumbnailer.thumbnailer
and edit it to read as follows:If you've a raw.thumbnailer or similar, delete it.
Quit Nautilus and delete the thumbnail cache (or it won't even try to regenerate previously-failed thumbnails) with
rm -rf ~/.cache/thumbnails/*
then open Nautilus and browse to a directory with raw files in it.Seems a bit slower than the old ufraw-batch method, but it's working here!