Interesting Proposal

[amutch]

Depending on the map, you might find JPG to be a better format. We generate static maps in that format from ArcView. For our online mapping app, we use GIF. Our next version will probably use PNG.

[wget]

Depending on the map, you might find JPG to be a better format.

Isn't jpeg better at dealing with things like photos. I think the jpeg artifacts are too noticable when you compress maps that consist of line-art.

[amutch]

In some cases, you are dealing with aerial photos or other maps that have a large number of colors that GIF and others don't display well.

[flii]

i know that's how i decide whether to use gif or jpg. gif is nice in that it animates, has transparency, and clear lines, but for pictures with more than 256 colors, gif looks horrible. they both have definate advantages.

[xfranky]

What about PNGs???

[flii]

What about PNGs???

believe it or not, i only learned about png from lynch when he was talking about his themes. before that i always used gifs. what are the goods and bads of png vs gif? i really haven't seen any, except sites that complain gif will be taken away.

[priior]

flii: the reason u dont see much png around is because ie doesnt support them :-/

but for an internal database project... png would probably be the best choice!

[seb]

IE6 does support .png files. It only doesn't support the alpha transparency layer of PNG (normal transparency works).
IE5-Mac has a full support of PNG files.

[priior]

netsabes: mea culpa. i should have mentioned "doesnt fully support"...

[wget]

In some cases, you are dealing with aerial photos or other maps that have a large number of colors that GIF and others don't display well.

PNG isn't limited by a 256 color palette.

what are the goods and bads of png vs gif?

There's license issues with the .gif format. PNG is a free (and Free) standard not controlled by a corporation. Freedom aside, it also produces smaller files (usually), it supports an alpha channel (this is a very nice feature) and it has a larger color space (gif only supports 256 colors).

[rbrimhall]

Found out that I can export arcmap files as PNG with an extension... cool that ESRI (the top GIS solution) supports this format.

[djst]

IE6 does support .png files. It only doesn't support the alpha transparency layer of PNG (normal transparency works).
IE5-Mac has a full support of PNG files.

Actually, it doesn't really matter if you have IE6 or IE5 installed. On Windows XP, png:s are supported, but on NT4 they are not, regardless of what version of IE you have installed.

Appearantly (and not quite surprisingly), it's an OS feature.

[seb]

IE5-mac is totally different from IE5-PC or IE6-PC. They do not use the same rendering engine, and in some domains, IE5-mac is far better than IE-PC (they have a better CSS support, for example, and of course a full support of PNG).
And I highly doubt that IE6 on WinXP supports PNG's alpha transparency :) I would be surprised.

[wget]

And I highly doubt that IE6 on WinXP supports PNG's alpha transparency

It doesn't.

... and in other news, Hell is still awfully warm.

[Stefan]

What about PNGs???

believe it or not, i only learned about png from lynch when he was talking about his themes. before that i always used gifs. what are the goods and bads of png vs gif?

PNG is better in every possible aspect.

The only advantage GIF has is that the animated version of PNG (called MNG) is badly supported in browers, and that is of cource not an issue of PNG/MNG itself but due to lazy browsermanufacturers.

Gecko BTW support MNG.