GIF89a support in IDL

[Bob Yantosca <bmy(at)triton.harvard.edu>]

Hi all,

After upgrading to IDL v. 5.2.1 (and searching the help pages in
vain!), I've come to the conclusion that the WRITE_GIF routine still
contains the following drawbacks:

(1) The output file is in GIF87a format, not GIF89a format.
(2) When using /MULTIPLE to write multiple frames to a GIF file, you
    cannot set the delay between successive frames.  

I'm interested in writing out a GIF89a file directly from IDL.  Currently
we have been writing each frame to a separate GIF87a file via WRITE_GIF.
Then we link all of the individual GIF's together into a GIF89a file with
"whirlgif" (a Unix utility program).  This process is slow and somewhat
cumbersome (and taxing of disk space, to say the least). 

Does anyone know of any existing IDL routines that can write out to
GIF89a format?  I was under the impression that IDL 5.2 could do this but
evidently I am mistaken.

Thanks a bunch,

Bob Y.
---
Bob Yantosca          | Phone: (617) 495-4517   \  "Ooooh...floor pie!"
Scientific Programmer | FAX:   (617) 495-4551    \    -- Homer J. Simpson
Atmospheric Chemistry | Email: bmy@io.harvard.edu +------------------------- 
Harvard University    | WWW:   http://www-as.harvard.edu/people/staff/bmy/