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IceTeks Articles -> Image Format Breakdown


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Red Squirrel - Dec-02-2005 server time
Seems to work at my end. (typical tech support line)

glennsharrock - Dec-02-2005 server time
the image of the Squirrel seems to be missing (I would very much like to see the image in which the results were made)

Lo Yuk Fai - Nov-19-2004 server time
This (http://www.c3.lanl.gov/~brislawn/JPEG_demo) maybe a better read.

Lo Yuk Fai - Nov-19-2004 server time
http://www.jpeg.org/jpeg2000/ <-- Check out the FAQ section.

rovingcowboy - Nov-18-2004 server time
are you tired of me coming to this site red? you seem to not like it that i use I.E.
most the time.

blink.gif

even though everything you say don't work in ie seems to work in my copy of it? cool.gif

i have not tryed transperent png's yet but everything else works.?

when it has not crashed that is em320.gif

Red Squirrel - Nov-17-2004 server time
JPEG 2000? Never heard of those. I can maybe do some research. Are they even supported by most browsers? It would definatly be nice to see IE support those but meanwhile... just screw IE. laugh.gif

Lo Yuk Fai - Nov-17-2004 server time
Good walk-through and tests.

IIRC, PNG was promoted as the replacement of GIF especially a few years ago, that the owner of one of the algorithm (or something like that) used in GIF began to charge royalties. And PNG's technically superior, of course.

Since then, the copyright (or patent? I forgot...) has expired and PNG is still not well-supported in the major browser -- Internet Explorer, much limiting its popularity.

I would like to see JPEG 2000 added to the tests, BTW.

Nezuji - Nov-15-2004 server time
Your discussion of the GIF format and its comparison to PNG misses a few things.

* GIF actually compresses images by first codifying them as rectangular areas of detail over a background colour, then applying an LZ-based compression to these areas.
* The PNG format has a larger header than the GIF format; Even when two identical images are both fully optimised, the PNG can be up to twice the size for small, icon-sized images. Over mid-size to large images, however, PNG does beat GIF for size due to better overall compression.
* Finally, the GIF 89a specification actually allows a loophole for having more than 256 colours (in fact, an infinite number) in one image, although most programs remove this possibility by implementing a technically incorrect (but not explicitly ruled out) behaviour.

Otherwise, a very useful article, and a good read!

Nezuji smile.gif

Red Squirrel - Nov-15-2004 server time
LOL I'll have to check if they have volume discounts. laugh.gif

sintekk - Nov-15-2004 server time
Screw IE Users eh? That's 95% of the interweb you're going to be screwing, so you'll probably need this website a lot...

http://www.condomdepot.com/

laugh.gif

Red Squirrel - Nov-15-2004 server time
I say screw IE users. laugh.gif I usually just try to avoid using trasparancy though it's so tempting because transparancy rocks!

sintekk - Nov-15-2004 server time
PNGs are supergreat, but I hold off on using them on my designs until IE gets the transparency right.

Red Squirrel - Nov-15-2004 server time
The other types of compression are less used and most programs don't even let you choose any levels like with JPG so it would of been a bit harder to do. Photoshop is the industry standard so I based the compression on that.

Paint for example, wont let you decide what compression to use for jpg, in fact only some versions actually support jpgs. For example on my win2k computer it lets me open/save as jpg, but if I go on another win2k machine it might not, not sure why it's like that.

Though in the future I may make another on a specific format such as PNG, since PNGs are pretty great and have lot of optimization options.

Digital Oracle - Nov-15-2004 server time
QUOTE (Digital Oracle @ Nov 15 2004, 02:51 PM)
I noticed that u mentioned in the article that other programs handle compression differently than Photoshop. But in your JPEG example, u only compared it to the quality produced with PS, and not with other graphics programs. Like MS Paint which comes free with every version of windows or GIMP which is free also free and works on many OS platforms. I do understand this is not a comparation or a review of other graphic programs, but some examples would of helped.

Plus going back to the JPEG example, u mention the other formants and explain how they would in the first 2 pages, but when actually comparing them, I would of like to see a similar example to what u did with the JPEGs. Because of this, what began sounding like an impressive article about graphic formats, was cut short and only feels half done.

Other than the above two points, I liked the article, and found things like header information interesting. The first page was very well researched.

Oh I also forgot to mention, with each new version of Windows, the MS Paint programs began supporting more formats. The one that comes with Windows XP supports all the mentioned formats that are talked about in the article, as well as the TIFF format.

Digital Oracle - Nov-15-2004 server time
I noticed that u mentioned in the article that other programs handle compression differently than Photoshop. But in your JPEG example, u only compared it to the quality produced with PS, and not with other graphics programs. Like MS Paint which comes free with every version of windows or GIMP which is free also free and works on many OS platforms. I do understand this is not a comparation or a review of other graphic programs, but some examples would of helped.

Plus going back to the JPEG example, u mention the other formants and explain how they would in the first 2 pages, but when actually comparing them, I would of like to see a similar example to what u did with the JPEGs. Because of this, what began sounding like an impressive article about graphic formats, was cut short and only feels half done.

Other than the above two points, I liked the article, and found things like header information interesting. The first page was very well researched.

BetrayerX - Nov-15-2004 server time
Very informative. A little history on the formats would have been nice, yet I enjoyed it pretty much. em194.gif

Vially - Nov-15-2004 server time
Well done, I felt the need to read something else than the latest comparison between pentium 10 and amd xx... We need to have more of this stuff for general use, like compression standards, file formats, how different suff work in our computers.... Thank you :)

Chris Vogel - Nov-12-2004 server time
That’s a great article! At first, it may be hard to know what format is best for what, but your article does a great job of pointing out the best uses for each. smile.gif

I know you note this at the end of the article, but the PNG tests on the simple image are not optimised. 24-bit PNGs are overkill for such a limited amount of colour. Just testing one size, I found an indexed PNG beats every other format, and I would bet that goes for other sizes as well.

PNG also has gamma correction, although sometimes that is an annoyance rather than a feature. Fortunately, it’s optional. I know this isn’t about the PNG format specifically, but Internet Explorer has a problem with PNG transparency if the PNG is not 8-bit.

Red Squirrel - Nov-12-2004 server time
In this article we take a look at various characteristics of 4 popular image formats and let you decide which one is best for which situation. We look at file sizes, compression options and other features.

http://www.iceteks.com/articles.php/imageformats

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