Shall I use JPEG or PNG?

[MickinPlymouth]

Hi, I regularly post screenshots and photos in military strategy game forums, usually in JPEG format, but just recently I've notice PNG gives slightly sharper results, so shall I go on using that in future, or are there some drawbacks that i don't know about?
I'm PC-illiterate and can't understand why anybody should want to use JPEG if its not as good?
PS - And why is JPEG sometimes called JPG, are they the same?
I'm Win XP Home
Thanks

[giradman]

JPEG = Joint Photographic Expert's Group - a format developed to reduce the size of grahpic files for easier display on the internet; plenty of 'compression' options available - the *.jpg extension is the more commonly used for this format.

PNG = Portable Network Graphics - a replacement for the GIF format - yes, different; either would likely work, but for pics, the JPEG format would likely be fine to use if a 'lossy' compression file is acceptable.

Check HERE (http://www.webopedia.com/DidYouKnow/Internet/2002/JPG_GIF_PNG.asp) for a brief description of the differences - there are plenty of other links that you can check out, as needed - good luck! :happy:

[oracle128]

.jpeg and .jpg are the same, .jpg was only used because old operating systems didn't allow more than 3 characters for the extension (eg. MS-DOS's 8.3 format).

JPEG uses lossy compression, which means it can compress better at the expense of losing some clarity in the picture. PNG is lossless, but results in bigger files.

But it also depends on what's in the image as to which compression algorithms will work better. For example, I took two screenshots of my desktop - one with my browser open full screen to CTH (a few solid colours), one of my wallpaper, a quality detailed 3D render. In the first, the JPG was 156KB, the PNG 71.2KB. In the second, the JPG was 232KB, the PNG 2.0MB. In both cases, the PNG was better quality; the JPG would change some colours slightly, solid colours turned into checker boards, and text had messy 'crumbs' around them visible when zoomed in. The PNG was smaller for solid, continuous areas of colour (as in the CTH site), but was nearly 9 times larger with a detailed image (in the case of my wallpaper).

For reference, this is my wallpaper (http://www.pokedstudio.com/pacmanwallpaper.htm).

So you need to choose one based on your needs. If you're not sure which one will turn out about, save to both formats, and see if the PNG's size is bearable.

[simplyg123]

png is the best, unless for transparency, then id use gif because not all browsers support transparent png which sucks cause the png quality is awesome.