[6744] in www-talk@info.cern.ch
Re: Interlaced vs. Non-interlaced GIFs
daemon@ATHENA.MIT.EDU (Chris Lilley, Computer Graphics Un)
Mon Nov 21 16:23:29 1994
Date: Mon, 21 Nov 1994 21:52:35 +0100
Errors-To: listmaster@www0.cern.ch
Reply-To: lilley@v5.cgu.mcc.ac.uk
From: lilley@v5.cgu.mcc.ac.uk (Chris Lilley, Computer Graphics Unit)
To: Multiple recipients of list <www-talk@www0.cern.ch>
Bill O'Donnell said:
> David Koblas said:
>> when I rasterize line drawings is the following process:
>> Frame -> postscript @ 150 dpi -> scale 50% -> GIF
>> This results in an nice anti-aliased image.
Yes. I wish more people would do this.
> ("Inline"
> (:gif :inline nil nil 75)
> :output "<IMG $=SRC $=ALT $?ISMAP>")
> Where the second line is (FORMAT INLINE|EXTERNAL TRANSPARENT THUMBNAIL RES)
which seems to preclude this anti-aliasing. Could I suggest
(FORMAT INLINE|EXTERNAL TRANSPARENT THUMBNAIL RES SAMPLES-PER-PIXEL)
where SAMPLES-PER-PIXEL is 1, 4, or 9 (maybe that sould be 1,2,3 on the
understanding it is always squared) to allow for antialiasing or not as a user
pref. Bear in mind though that antialiasing and transparent gifs interact - the
rough background colour has to be antialiased to.
BTW the syntax quoted does not seem to allow you to specify what colour is
transparent, do you assume white? or is the parameter an RGB value if it is not
NIL. (So, in the GUI, users click on the image to say what colour they want
transparent).
--
Chris
