[pdftex] Image transparency

[Robin Fairbairns]

> I nearly said that I thought the advice was outdated: Netscape 4.7, 6.01 and
> IE5.5 seem fine with all my png images.

this is all very well (and true), but sadly not everyone in the world
uses the latest versions of things.

i seldom put up web pages for any purpose other than gently informing
the world about me and things i'm interested in.  if i get complaints
i can tell the complainer to upgrade or do without.

wendy (who afaict started this thread) has a short timescale to
advertise something important doesn't have that luxury.  even if she
felt able to tell people to upgrade, the time taken would represent a
lost opportunity.

so the demise of the much-despised gif format relies on people like
you (no doubt) and me: we must make enough information available out
there, that uses png and the like, that there's a strong incentive for
joe user to upgrade his browser.  once enough have upgraded, gif
(which is in fact inferior anyway) will wither on the vine.

robin