Any trick to get CR3 file thumbnails to show up in KDE / Dolphin / Plasma


I’m running Kubuntu 22.04 / Plasma Version 5.24.6.

I recently got a new Canon camera and Dolphin, the KDE default file manager, cannot show thumbnails for the CR3 raw files that the camera makes.

Gwenview, the default photo app also cannot read these CR3s.

Both Dolphin and Gwenview worked fine on just about all the other raw formats that I’ve used.

It seems that Digikam and Rawtherapee work fine even on CR3s.

Has anyone else run into this problem on KDE Plasma, and how did you fix it?

What version of exiv2 do you have and what are the compile flags?

FYI, some CR3s (presumably ones shot in HDR mode) contain thumbnails in an unknown format.

I installed it from the ubuntu repositories just now. It’s version 0.27.5.

I’m not sure how to check the compile flags.

Run exiv2 -vV and then look for enable_bmff - should have a value of 1.

If so, run exiv2 -pp <foo>.CR3 to see if the preview is the regular JPEG or the proprietary Canon HDR thumbnail.

So far, so good?

$ exiv2 -vV | grep enable_bmff
$ exiv2 -pp IMG_0150.CR3 
Preview 1: image/jpeg, 160x120 pixels, 21833 bytes
Preview 2: image/jpeg, 1620x1080 pixels, 481039 bytes

Yes, but this is where my knowledge stops unfortunately - no idea how KDE apps extract previews, whether they actually use exiv2, etc.