Definition of a PNG file (vs. Gif)

[Graeme]

Can anyone explain to me the definition ofa PNG file and it's uses as well as it's contrast to the uses of a Gif File.

Cheers;)

[kaotic]

well to start of i will show you an example of the difference
heres the gif
www.racksmart.net\picsforyourmother\gif.gif

and heres the png
www.racksmart.net\picsforyourmother\png.png


as you can see microsoft internet explorer cannot show png files
where as it can show gif
the second biggest difference is file size and quality


hold on while i figure out the **** likns to the uploaded files

[Laslett]

Gif only supports 256 colours and one transparant

PNG supports lots of colours and an alpha channel allowing degrees of transparancy

[DDD]

png basically is jpg quality with transparency. so you can have good gradients and more colors present. which equal better quality

the drawback. Is it is not wise to use outside of flash since it is not an w3c standard most browser/OS combos will discolor it. But to use in flash it is ideal but you can generate large file sizes.

[λ]

a png is an open source file format intended to replace gifs.

It was designed because of patent problems with the .gif format (a company called Unisys copyrighted it, so you have to pay big bucks for a license to write them), and also because of the limitations of the GIF format(256 colours, binary transparency, etc). It was originally designed for the web.

however, many browsers have non-existing or poor support for PNGs, so what was originally designed as a web format ends up being used for importing into Flash and such :) .

EDIT: And actually DDD, it is the only web format in use today which is a w3c standard : http://www.w3.org/Graphics/PNG/

[Graeme]

Yeah I really should have checked the w3c, didn't think of that. I had been getting some bad feedback about using PNG files in places other than flash. But they never told me what they actually were, and I guess I never bothered to find out. But thanks guys! I appreciate it!

Cheers;)

PS: I have book, it is part of the W3C thing, I also should have looked here to:P. http://www.amazon.com/exec/obidos/tg/detail/-/0735712018/103-3860591-5151064?v=glance

Check it out! it's great.

[DDD]

hhmmm not sure if recommendation means it has become a standard, but thanks for the link.

[Nocturn]

Again with the PNG's lol....
This confusion exists I think because of the different kinds of transparency that the png format supports. You can have a "normal" png with on/off transparency, just like a gif. This type of png will work just fine in ANY browser, it will NOT look any different on different browsers or OS just because it's a png.

If it looks different because of the OS (Mac vs Win), it's because everything, every picture regardless of format, looks different between a Mac and Win. It's because of different gamma settings. Then you have the issue of monitor calibration.

In short, go ahead and use the normal 8 bit png's, they will work just like gifs, but they will usually compress better than gifs. But not if saved out of Photoshop, PS doesn't save png's very efficiently, it adds stuff to them, which you don't need. But there are small apps out there that will strip a png so it only contains necessary data.

Just look at the PNG website for more info than you'll ever need:
http://www.libpng.org/pub/png/

Finally, the problem with the 24 bit png (the ones that use 8 bits for the transparency=256 levels of transparency), is because IE still doesn't support them properly and will display the transparent part as grey muck. The only version of IE that supports this version of png properly is IE 5.5, for the Mac lol....
Even Microsoft software runs better on Mac than it does on Windows.

[λ]

There is a way of making 24 bit .png's work on ie...

There is an article on www.alistapart.com <- great site

[Marz]

PNG is also one of the only img languages that can be dynamically created by use of IE scripting ;)

[DDD]

hahahaha.....marz you are the scripting king :beam:.....If given the chance you would build everything dynamically huh? Screw DW, PS, FW, FMX, AI........script it all yourself...hahahahahaha

alright back to topic

[Marz]

As a matter of fact....

*lmao*... I use to script all my graphics for my games in DOS.. instead of figuring out how to import bitmaps ;)

But yes.. back to topic.. We apologize :D