Of course. I don't do any image and many other stuff that can't be modified later. In this particular case I didn't save it as xcf because I did it for training in 5 minutes.
My background/raster image knowledge:
- no previous raster image editing background
- seen some GimpKnowHow YouTube tutorials
- xcf GIMP format, lossy vs lossless image formats, quality settings with preview, including indexed GIF, cdds plug-in
- canvas, layers (+opacity, alpha channel and layer mask) and selection basics (+ floating selection)
- all the basic transformations (rotating, scaling, cropping etc.), copying, pasting, moving selections
- basic usage of all the selection tools incl. feathering
- basic usage of all the paint tools
- gradient tool
- erm... all the tools in the toolbox, so it looks
- some filters of name clearly indicating the final effect
- VERY poor at all the stuff involving color manipulation (lack of theoretical preliminaries) (except of what's RGB and HTML color notation)
- Very poor at Layer Modes which I know have great potential
Generally I would be grateful if someone could supplement this list with missing BASIC stuff (including needed theory). Followed by top 10 most underrated image manipulation program functions (from basic to intermediate) and top GIMP tricks that allow achieving quick effects almost like some Picasa manipulations. I went through some chapters of the gimp.org documentation but it's obviously not relevance structured.
I've been playing with layer mask
T = ~20 minutes. It's not ready. It's just a playground, obviously.