Viewing HEIC images in gnome Image Viewer
Recently I've been backing up some iPhone photos. These photos have been in the HEIC format and that was not supported by Image Viewer and this made it hard to review them.
It was possible to get this to work by installing a missing package:
$ sudo apt install heif-gdk-pixbuf
After installing this I could see these photos in the Gnome Image Viewer application.