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petite minotaure
10-12-2006, 07:09 PM
I'm working on a file that another programmer created. All of the images used are in .png format. I'm not familiar with this format and have always used .jpgs.

Can anyone tell me about .pngs and if there is an advantage or disadvantage to using them?

Also, if I save something as a .png in photoshop are there certain settings I should use if I'm going to be putting it in Flash?

Thanks.

Wispa
10-12-2006, 07:55 PM
From what I remember PNG (Portable Network Graphic) image compression was developed as a free alternative to GIF or JPG files. I believe that if you were to create an image manipulation software package and wanted to give the option to export as either JPG or GIF files, you'd have to pay for the rights of using those methods of image compression. As far as I know it's free if you want to use the PNG compression in user made software. I may be incorrect as it's just a vague memory from Uni education :rolleyes:



I'm not too sure about the advantages/disadvantages except I know that PNG files can use layers and transparency but some pieces of software may not recognise them.

senocular
10-12-2006, 08:10 PM
PNG is also the native file format for Adobe Fireworks, so its possible they are source files.

stompwampa
10-14-2006, 05:23 PM
png is to fireworks as psd is to photoshop. However, you can open up png files in most basic image viewers (such as Windows Picture/Media/Fax Viewer)

Keeper
10-14-2006, 08:07 PM
PNGs take some of the best traits of both JPG and GIF, at the expense of some filesize (But not much unles the picture is very big and detailed).

A PNG has the high image quality and blending of a JPG as well as the possiblity for transparency from GIFs.

senocular
10-14-2006, 08:45 PM
"at the expense of some filesize" is not always the case. There are many times PNGs look better and are smaller file size than JPGs and/or GIFs.

pan69
10-15-2006, 05:39 AM
JPEG uses a lossy compression method. Basicly this means that it destroys data to achive compression. See http://en.wikipedia.org/wiki/Lossy_compression

PNG, GIF, TIFF etc. use a lossless compression method. Basicly it keeps the original data intact while achiving compression. http://en.wikipedia.org/wiki/Lossless

Unless you're dealing with photos always use PNG. These is no other format that can achive as much as PNG can. For example, GIF can only be stored up to 8 bits per pixel (256 colors) where PNG can go up to 32 bits. GIF can include a transparency color where as PNG can include an alpha channel (which is ofcourse superior because this includes anti-aliasing). GIF is old, it has seved its purpose very well during the 90's but this is the age of PNG.

http://www.lukeschreur.com

petite minotaure
10-16-2006, 12:23 PM
thank you everyone for your responses. I think I understand better now.

invader
10-17-2006, 07:06 AM
don't PNGs get exported at the compression in the publish settings while JPGs by default retain the compression the file was imported with?

when you're dealing with a lot of pictures and file size is a concern, it's nice to know that you don't have to tweak each image in the library individually

pan69
10-17-2006, 07:28 AM
don't PNGs get exported at the compression in the publish settings while JPGs by default retain the compression the file was imported with?
Nope, thats a matter of the settings your choose. Select properties of your library bitmap and choose the compression type (lossless/Photo), see my earlier post for the difference. If you choose Photo (JPEG) you can choose if you want to use the Flash compression settings or keep the original file settings.

http://www.lukeschreur.com

red01
10-24-2006, 03:45 AM
Png's are great if you want to have nice apha transparency