Path: utzoo!attcan!uunet!mcsun!i2unix!inria!geocub!deimos.greco-prog.fr!pat
From: pat@deimos.greco-prog.fr (Lutmann Patrice)
Newsgroups: comp.windows.x
Subject: Question about (XGetImage & XGetSubImage)'s velocity!
Keywords: X11R4, DS3100 Color, XImage
Message-ID: <241@geocub.greco-prog.fr>
Date: 13 Sep 90 14:33:41 GMT
Sender: remacle@geocub.greco-prog.fr
Organization: CICBx - University of Bordeaux I - FRANCE
Lines: 29


	Hi!

	The problem: I'd like to do some rudimentary screen dumps
	and if possible, very quickly.
	I can do that using XGetImage or XGetSubImage. The manual
	says that XGetImage allocates both the XImage structure
	and the space for the image itself, but XGetSubImage just
	updates the XImage structure passed as argument. In some
	cases, I want to update an existing XImage, so, XGetSubImage
	seems to be a good way... :-( but... it's *SLOWER* than 
	XGetImage (which creates a new one).

	I do some screen dumps (image size: 300x300):
		with XGetImage, it takes about 0.1 s.
		with XGetSubImage, it takes more than 5 s.

	Could someone tell my why? Is there a better method? I'm
	working on a DS3100 (color), 16 Mb, and X11R4 of course.



					Pat.


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	Pat@deimos.Greco-Prog.Fr		[]	Computer Science
	..!Uunet!Mcsun!Inria!Geocub!Deimos!Pat	[]	    C.I.C.B.X 
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