I don't know if this is still useful to you, but for anybody with the same question.
EDIT:
link:
http://pippin.gimp.org/tv/You can use a terminal program called: tv
I don't remember where i downloaded, but if i recall, it was in a web page of a developer doing something with GIMP, i think. Maybe GPLv2, so i guess if put it in the Extension section i have to give the sourcecode, anyway GPL it's to messy and submit a binary it's not allowed, doing a quick search i can't find it, good look using a search engine.If i can upload the binary i'll put it here, but for now you have a screenshot.With utf8-256 the images looks really good, but you can read screenshots if you zoom enough with ./tv -m ascii *.png.
./tv --help
EDIT:
You don't need any Framebuffer support or any graphic extension, the little program does a pixel conversion to text data of jpg, png and gif.