Graphics Format

[zigar]

leaving png aside...since it's not yet 100% supported...you should really be using both gif and jpg...they do different things..gif is good for things like text, buttons and similar where you have few colors and "sharpness" is important...because of jpg's lossy compression, it is not good for things with sharp, defined edges...they tend to look blurred and hard to read...jpg on the other hand is great for images which have naturally blurred edges...like a photograph...also if you want to do fancy web tricks like mouse overs...jpg isn't good beacuse you often want transparency in the graphics with the onmouse events...



HERE'S a good intro to web graphics....

[LadyBug]

Zigar, what do you mean when you say PNG is not 100% supported? As far as browsers go , after 4.0 they (ie & netscape) displayed them fine...webservers too.

[zigar]

? As far as browsers go , after 4.0 they (ie & netscape) displayed them fine...webservers too.

mmm...only sort of....there are an awful lot of if's and maybe's to be called 100% supported...even with v5.0's

from http://www.libpng.org/pub/png/pngapbr.html

Internet Explorer [Microsoft] (Mac PPC) - version 5.0 and later; read-only; full alpha support (screenshots); full gamma support; full sRGB and ICC profile support; progressive display of interlaced images (replicating method); uses libpng and zlib; freeware. (Note that AOL 5.0 is apparently built on MSIE 4.5 or earlier, so it has no PNG support at all. No word on later versions.)

Internet Explorer [Microsoft] (Windows 9x/NT, Solaris/X, HP-UX/X) - version 4.0b1 and later; read-only; broken alpha support in Windows versions 4.0b2 through 6.0;1 full gamma support; progressive display of interlaced images (replicating method); broken OBJECT support;2 version 4.0 crashes on large PNG chunks;3 version 5.0 prints palette images with black (or dark gray) backgrounds under Win98, sometimes with radically altered colors;4 fails to display PNG images used as CSS backgrounds; sometimes completely loses ability to display PNGs (see FAQ page for various fixes); freeware. (Note that Microsoft claims version 4.0 ``does not include the functionality to view .png files,'' which presumably refers to its inability to display stand-alone PNGs;5 this is partly fixed in 5.0.6 Note also that the Windows 3.x version of IE has no PNG support at all, but the IE-based AOL browser for Windows does, at least from version 4.0 onward.) Bugs and other feedback--such as requests for full alpha support--can be reported on the MSIE 6.0 beta feedback page (which requires registration but no cookies) and/or the Microsoft product feedback page (which doesn't appear to require any personal information). Also check out Aaron Adams' petition for full PNG support in MSIE/Windows .
simple transparency only, with bad threshold for transparency vs. opacity, and only for palette images; completely fails to render some transparent palette images (e.g., bottom four here], possibly due to filenames with more than one dot(?!); non-palette images are rendered fully opaque against a light gray background; alpha transparency supported if and only if HTML content is rewritten to use Microsoft-specific DirectX extensions to CSS (further caveats for DirectX approach: if the PNG image's width and height attributes are missing, the width and height of the placeholder image will be used instead; if the placeholder image is missing, the browser's stock ``missing-image'' icon will be placed over the PNG)
only if "Run ActiveX controls and plug-ins" security preference enabled; adds unnecessary scrollbars; version 4.0 renders all OBJECTs in nested set, not just outermost
especially those created with the "Save" function in Macromedia Fireworks--use "Export" for final PNGs
reportedly fixed in version 5.5, and doesn't affect NT or Win2k
i.e., those that are simply referenced via links or opened from disk--it can view ones that are inlined on an HTML page via IMG tags just fine
i.e., it works on some systems but not on others, and it's not directly related to running NT vs. Windows 9x but may have something to do with other PNG-capable viewers being installed

in fact MS is so wishy washy about png that someones even started a petition to get them to fully implement it...

http://www.petitiononline.com/msiepng/petition.html

Netscape Navigator [Netscape Communications] (Unix/X, Windows 9x/NT, Mac OS, OS/2) - version 4.04 and later; progressive display (replicating method); full alpha and gamma support as of version 6.0PR2 (see Mozilla above) but no transparency or gamma support whatsoever in version 4.x; nearly complete MNG and JNG support in version 6.0 and later (see MNG apps page for limitations and bugs); versions 4.04 through 4.76 treat black as transparent in opaque palette images with a background chunk (test) and reportedly do even worse with 64-bit RGBA images; limits image size to linear dimensions of 8000 pixels; attempts to display invalid PNGs; versions 4.04 through 4.5 have a bug in their ``Accept'' headers (missing comma) that causes Microsoft Internet Information Server (IIS) and Oracle Application Server not to send static PNG images (images dynamically generated by CGI or ASP scripts are apparently not affected; bug is fixed in versions 4.51 and later); uses libpng and zlib; freeware. (Version 2.0 and later also support PNG via the plug-ins listed below, but note that Netscape plug-ins currently do not support true inlined images--they only support images inlined with Netscape's non-standard EMBED tag, which is not usable by most other browsers, or with HTML 4.0's OBJECT tag, as long as HEIGHT and WIDTH attributes are included in the tag. In any case, Netscape 4.x's OBJECT support is broken, too. Version 6.0, however, is based on Mozilla, which has excellent OBJECT, PNG and MNG support.)

[ac1dsp3ctrum]

I use mostly JPG's becaus eof the great compression ratio and quality

[pwaring]

PNG is the best format, because it offers far superior compression in comparison to GIFs and isn't a proprietory format so you won't get sued by whoever owns the patent if you incorporate it into an image creation package.

I use JPEGs occasionally for photographical images, but I'm slowly moving everything over to PNG as more and more browsers support this format.

[BB_Wolf]

Suck an elf!?

I always used Photoshop to export png files.. I was to say at least NOT impressed..
So I just kept to the good old Gif and Jpeg (depending on the kind of picture)..

Going to try gif2png as Rewandythal said.
I am anxious to give it a try!