darktable : A virtual lighttable and darkroom for photographers ( https://www.darktable.org/ )
enblend : Image Blending with Multiresolution Splines ( http://enblend.sourceforge.net/ )
hugin : GUI for the creation and processing of panoramic images ( http://hugin.sf.net )
multiblend : A multi-level image blender for the seamless blending of panoramic images ( http://horman.net/multiblend/ )
nufraw : A new version of the popular raw digital images manipulator ufraw. ( http://matteolucarelli.altervista.org/nufraw/ )
siril : a free astronomical image processing software ( https://www.siril.org/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a maekke
For Paludis use this rsync : rsync://gentoo.zugaina.org/maekke-portage
If you have a problem : ycarus(-at-)zugaina.org