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Re: transparent GIF pixels

Kenneth Mankoff <mankoff@lasp.colorado.edu> writes:
> I'm using ION to make images for a website. ION is "IDL On [the] Net"
> For those of you who know html, its really as simple as this to generate
> images:
> <html>
> <ion_img>
> <idl>
>    ;;; idl code goes here
> </idl>
> </ion_img>
> </html>
> and *wow*, you have a gif or jpeg _inside_ your web page that is generated
> based upon inputs supplied to the page by the user.
> But, yes, GIF's can have pixels that are transparent in that they show the
> background through them. WRITE_PNG has a transparent option, so i could
> write a PNG with transparent pixels, then re-read it the NEXT command
> (this stupid and slow), and then display that image to the page, and have
> my transparent (see-through) pixels.
> But i would prefer to do all that in memory, rather than using the
> webserver to needlessly read/write to PNG image.

I hear you Ken.  I am a little surprised that ION doesn't have any
more web-friendly functionality than straight IDL does
(e.g. transparent gifs).


Craig B. Markwardt, Ph.D.         EMAIL:    craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response