Fast Screenshot without blocking X events

[Alan Coopersmith]

GORIN Guillaume wrote:
> -I need something that is really fast (0.1 second maximum for capturing
>  and saving the frame in RAM) (I capture the maximum of frames to encode
> in a video)

The technique used by screen magnifiers, which have to capture,
scale, and display images in real time is to use the Damage extension
to minimize how much of the screen they have to grab in each operation,
limiting it to just the changed bits, not a full screen dump.

-- 
     -Alan Coopersmith-           alan.coopersmith at sun.com
      Sun Microsystems, Inc. - X Window System Engineering