What is the most advanced image editing FLOSS?
Is it still GIMP? Inkscape? Are they too different to compare? Does anything come close to the two? Are they more/less advanced than Photoshop?
note: advanced = more features
GIMP and Inkscape aren’t comparable: GIMP is a bitmap editor, Inkscape is a vector graphics editor.
GIMP is the uncontested leader amongst open source bitmap editors, feature-wise. It ranks closely with Photoshop. However GIMP has poor support for the CMYK color space, which is used by most “serious” color printers; I’m told this makes it unsuitable for many applications. As usual Wikipedia has a comparison of raster graphics editors, which may or may not include all important criteria.
There are many different types of vector graphics. Inkscape is a leader in its field, which is two-dimensional general-purpose schemas and scalable graphics, made mainly of straight lines, simple curves and filled regions. Other programs may perform better for CAD, electronics schemas, geometrical constructions, state diagrams, fonts, 3D modeling, etc.
Krita is quite feature rich as far as capabilities if you like KDE software, I’m not really sure how it compare’s to GIMP, as I’m I don’t enjoy image editing, but I seem to recall reading it’s better at some things (CMYK Maybe? or what is color depth?) than the GIMP. From what I have seen/heard it’s a powerful that most people never seem to hear about. Here is a pre KDE 4 comparison of Krita and the GIMP.