Does anyone know a really fast way to grab a screenshot? I have attempted to use import but I don't want to save the image to a file straight up. The idea is to manipulated the image (compare/compress) THEN save. Does anyone know about accessing the frame buffer and manipulating (as well as compare and compress I need to know about manipulating bit depth). Someone told me that they thought there was something to do with SOCKETS that might help me out. Beyond that I'm stuck. My knowledge does not extend past xgrab and import commands. It seems I have a lot to learn on the subject. Can anyone enlighten me further.

it's for a program to do something along the lines of what VNC or RDP do only it requires bit conversion from 32 to 18 bits and I'm runnning it over wifi. Trying to take advantage of a fast wifi connection.
haven't used dev/fbo, in fact don't know much about the whole thing. I'm a newbie to Linux, only touched it for the first time last week! Any advice on what to do or where to find out?

Come to think of it, if there's an existing app or a couple of apps I can use together I'll do it but I need it to be GNU and better than VNC. I tryed that (a couple of different variations) and it was way below par for my liking. I figure it's mainly an issue with being able to access the screen buffer quickly enough and using as few processes as possible.
Any clues?