[thelist] AOL gif compression glitch?

Matt m at pleonasm.com
Tue May 22 02:27:18 CDT 2001

Erik Mattheis wrote:
> A friend took this screenshot of a gif for me from AOL - 
> discoloration on a portion of the image:
> <http://gozz.com/temporary/re/mn2.gif>

As others have noted, The default setting on AOL is for graphics to be
compressed, presumably to reduce server load. This became a real problem on
on site I was involved in, where the quality of the graphics was of
paramount importance; many people using AOL complained about the
blotchiness of the photos, although the originals were crystal clear.

What we did was put some browser-sniffing JavaScript in each page, so that
if the browser was AOL, a small link would appear beneath the photos (which
were only on one side of each page), saying "AOL users click here."
Clicking would make a small window pop up, containing gentle instructions
on how users could improve the appearance of graphics on this and all other
sites. When AOL 6 came out, the method of turning off decompression
changed, so there were then two sets of instructions. {sigh}

The JavaScript was (simplified):

function adviseAOL() {
   if (navigator.appVersion.indexOf('AOL') != -1) {     // i.e. if AOL
browser is being used
      *** make your browser do whatever you want here ***

I'm not a JavaScript expert and didn't code this; this is more for
illustration. I hope there isn't a flaw in it. Of course it won't work if
JavaScript is disabled, but maybe you can't disable JavaScript in AOL?

Anyway, it worked pretty well - we asked people about it, and a lot of AOL
users said they followed the instructions and turned off graphics
decompression. I'm sure some didn't, but they can't say they weren't advised.

HTH ... Matt

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