Interesting Proposal

[Stefan]

PNG ... ...it supports an alpha channel

Actually it supports up to 8-bit alpha even in index color ("GIF") mode (this is the part that is buggy in IE though).

And you can even have 16-bit alpha (in 64-bit mode, of cource graphicards don't support 48/64-bit color yet, so currently that is academic ).

[flii]

well stefan, you will have to educate me on what "all possible aspects" are because i am woefully ignorant of these wonders.

gif. makes a word. works fine.

png. ping? otherwise you have to say each letter, like html. bah. works almost fine except animated ones, which then need *another extension*. bah.

gif for me.

[rbrimhall]

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.

Are you guys using ArcIMS or Adobe Illustrator or something else?

As far as map quality, ArcMap quality drops significantly after export in both BMP and PNG
forms... Is the export better in JPEG or GIF? AI is the best since you can actually seperate individual layers but that would require my very underfunded department to invest in new software not offered under license...

[djst]

well stefan, you will have to educate me on what "all possible aspects" are because i am woefully ignorant of these wonders.

gif. makes a word. works fine.

png. ping? otherwise you have to say each letter, like html. bah. works almost fine except animated ones, which then need *another extension*. bah.

gif for me.

You're right. We should use a proprietary, patented format instead of an open, Free format, because gif makes a word and png doesn't. :o 8)

[Ashitaka]

png. ping?

ping.

[wget]

png. ping? otherwise you have to say each letter, like html. bah. works almost fine except animated ones, which then need *another extension*. bah.

Just call it "PNG's Not Gif". Easy to remember, right? 8)

gif for me.

It's your bandwidth.

[flii]

stefan, you know i meant that post specifically for you. lol. ok now to include the rest of the world...

@ash. do people really say ping?

@wget. "it's your bandwidth". i'm not seeing how bandwidth makes me use gif. sorry. that whole post was really meant to tease stefan and say he's so smart and i'm so dumb, and then i had to say something i think but something that's dumb, though true.

[willll]

@wget. "it's your bandwidth". :?: i'm not seeing how bandwidth makes me use gif. sorry. that whole post was really meant to tease stefan and say he's so smart and i'm so dumb, and then i had to say something i think but something that's dumb, though true.

i believe what he was trying to say that it is you bandwidth u are wasting by using the less size-efficient gif format.

[flii]

ah. gotcha. thanks. fortunately, i have a flat-rate cable connection. $30 a month and i'm unlimited except uploading. uploading speed is capped, but not how much i upload total.

what i see, though, is that png is over twice the size as gifs i create. i tried doing those two compression things (rewrite and something?) but i don't mix well with programs that go through dos. hence, my pngs aren't compressed, and my gifs are smaller. whether or not those two programs could make the png smaller i don't know.

same image's properties with both formats

[amutch]

rbrimhal,

We are currently using custom MO [Map Objects] application. Scary, I know! We use GIFs with that as PNG wasn't available at the time. It works fine for most of our maps, like zoning and voting precincts. The quality gets sketchy with our aerials. We are about to roll out ArcIMS and I'm pushing to use either PNG or JPG, depending on the application. We don't want to have to pay another license fee for GIF and most people are using browsers that provide PNG support. As far as ArcIMS, it's pretty easy to set up and they have some decent out-of-the-box apps. We had a custom app built but most of the functionality is available out of the box. Let me know if you want more details.

[Stefan]

stefan, you know i meant that post specifically for you. lol. ok now to include the rest of the world...

Hehe, I guess some people beat me to picking on you

@ash. do people really say ping?

I'm not Ash, but yes PNG is officially pronounced Ping (MNG = Ming).

[flii]

lol ok. i guess ping to me will always mean pinging first and png second.

on a completely unrelated note, i am not an addictive gamer... :angel:

[Stefan]

ah. gotcha. thanks. fortunately, i have a flat-rate cable connection. $30 a month and i'm unlimited except uploading. uploading speed is capped, but not how much i upload total.

Sounds like a bad deal.
I pay about $35 for flat rate TP connection, 5 IPs and 10Mbit up & down (servers for non bussiness use allowed)

what i see, though, is that png is over twice the size as gifs i create.

PNGs can have both index color and full 32-bit color.
Are you sure you are not saving a full color BMPimage into PNG (32-bit) vs GIF (8-bit aka indexed) ?

Put up the original image if you like and I'll give it a spin and see what size I get

i tried doing those two compression things (rewrite and something?) but i don't mix well with programs that go through dos.

Do .bat files still work under Win XP?
If it does create a new file called crush.bat in a texteditor and paste in the following
pngcrush -d crushed -brute *.png

If it's place in the same dir as your crush.exe together with some "uncrushed" png's, double clicking the crush.bat it will optimize their compression and copy each .png file into a subfolder called crushed.

BTW, the -brute means each of the 114 combinations of compressionmethods will be tried to find the absolute smallest size generated.
If you have several larg images and don't like sitting around waiting, leaving out the -brute is a smart thing to do (usually it's pretty good at guessing which is the best compression method).


The rewite proggy howevere is a bit more difficoult to work with.
But if you don't like DOS, try making a shortcut that looks something like this
C:\graphics\pngrewrite.exe in.png out.png
You will however have to rename the file you want to compress to in.png and the outputfile will be named out.png.

[flii]

well, really i only pay maybe $18 bucks for mine, because with bf's computer hooked up too, we pay $35 total.

here's the image i used. i needed a simple image, fairly big, a few diff colors, and had though to just make one, then i started messing with it. it's funked up, i know, but i only needed the size, not a very good pic. let me know when you get it and i'll take it back down.

i'm not on xp, i'm on me. dunno if bats work there, but they work for me. alanjstr gave me a bat that sorts lists, which i used on the names txt file.

[Stefan]

here's the image i used.

Yepp, that's a fullcolor 24-bit BMP all right.
To get a comparable PNG in quality you have to reduce the colors to indexed (otherwise you are compairing a much higher image qualiy PNG with the GIF).

Using 256 colors indexed and crushing (rewrite doesn't do very much with a full 256 colors pallet and no alpha transparency) leaves a PNG of 140kB (to be compaired with your 148kB GIF).

That is only a 5.4% saving in size, but it's also pretty much the worst case scenario (full 256 colors and no alpha).