That Red Tree (Black Crayon)
I made this photo using G'Mic for Gimp. I have actually made several different images off of this red tree. This one is my favorite. My second favorite is the red and yellow color shift. The original post is on Flickr.

If you are like me and view your photos with a program such as Eye of Gnome (EoG), then you will want to disable extrapolate in the dconf program in order to be able to zoom in and not have the photo blurred. Eye of Gnome is the default image viewer in Debian (and probably all Gnome based systems).