Converseen, the open-source batch image processor for Linux, has been available as a Flatpak package for a few months and now is finally able to properly support HEIC/HEIF formats, PDF without the need for additional dependencies, and all camera RAW formats supported by libraw.

Source: LXer – Converseen Open-Source Image Processor – Flatpak enhanced with Heif/Heic, PDF, LibRAW Support