[quote author=HandyMac link=1098998202/0#11 date=1099150207]I dunno where the idea that GIF is an obsolete format comes from. For sure it's a bit antiquated in terms of its technical specification (max 256 colours for example), but the last time I looked it was breeding very well. Since the Unisys patent timed out last year there's no royalty fees required to use it.
PNG is okay - but is NOT supported on all browsers. You take your chances putting a PNG on a web site that some of your customers might not see the content of the web page.
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the compression algorithm used in GIF is antiquated and PNG (at the same color depth) gives much smaller files
I strongly suspect that the vast majority of machiens old enough to have such a browser and online haven been junked or reformatted by now due to an infestation of viruses and spyware.if they haven't updated thier browser since the days when you could take a virgin windows install online and not get infected do you think there is much chance they have a firewall or up to date patches. and in all stats i have seen in recent times the number of people running 4.x browsers let alone anything older is vanishingly small
[quote author=HandyMac link=1098998202/0#11 date=1099150207]
JPG is good for photo's, but is a "lossy" type. Each time you save the image to disk you lose a few more pixels because of the way the compression algorithm works internally - it doesn't save every bit of information. After a while it becomes noticably ragged. You don't get that problem with GIF.
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true i was talking about formats for images on the web PNG is generally the best choice for archival
[quote author=HandyMac link=1098998202/0#11 date=1099150207]
When putting images on a web site it's always a good idea to compare the physical sizes on the hard disk, and choose the one which has the smallest footprint. Sometimes GIF wins, other times JPG. I don't think PNG is particularly brilliant in terms of compression (but I could be wrong about that - I don't use PNG).
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this may be the case on some types of mixed images but in most cases you can tell which is more appropriate from the type of image you are working with
[quote author=HandyMac link=1098998202/0#11 date=1099150207]
Check out the following web page for further information:
http://www.siriusweb.com/tutorials/gifvsjpg/ [/quote]
ok i started to read it (and was sorely dissapointed rather fast)
firstly there are no standards for the meanings of jpeg quality figures (in applications) and they are definately not percentages
secondly he didn't seem to have heared of optimised pallettes (see the first gif example)
thirdly looking at his patterened example gif we once again see what loooks like dithering. This is almost certainly caused by the use of a non-optimised pallette which is probablly bloating the filesize of the gif (he doesn't provide the source images either which makes suck details impossible to check)
for photorealistic images (whether from photo source or otherwise) he is correct that jpeg will win by far
now where does PNG fit into all this? well PNG provided three things to the web designer
1: freedom from the gif patent issues (no longer an issue but it was one of the main reasons for its introduction)
2: better compression than gif for a file with the
same parameters (unfortunately a lot of people made 24 bit pngs when 256 color or even 16 color would have been fine and then complained about filesize bloat)
3: lossless compression of 24 bit images. Theese can be usefull in some situations on the web although they should be used with care and only where neither JPEG nor a lower color depth of lossless image (PNG or GIF) is usable