Gmic 2.5.4 with Gimp 2.10 under Ubuntu 18.04

[Carmelo_DrRaw]

@rich2005

Comes the time when you want to update that 8 MB gmic_gimp-qt plugin and you have to download a whole new 156 MB appimage. IMHO madness.

As you might have noticed, this is now solved!

GIMP AppImage plug-ins moved to a separate repository

As you might know, I am providing since quite some time a Linux AppImage package for GIMP, both for stable releases and development snapshots. So far, the AppImages have been shipped in two versions, one only containing the GIMP application, and another one also containing several popular plug-ins. While this worked, the approach had few major drawbacks: the size of the package with plug-ins was obviously larger than the one without there was no way to decouple the versions of the various pl…