On Thu, 1 Feb 2001, Clarence Verge wrote: > > http://twovoyagers.com/IE_Arachne_X.png > > http://twovoyagers.com/IE_Arachne_X.html > > * > > What is wrong with this picture ?: > > Your .png was 144,610 bytes to download. > It took 1 MINUTE and 4 seconds to [download and] display > on my P90. I could have compressed it tighter, but then it would take longer to decode. With png, you can do a balancing act between download time vs. decompression time. I think I used a compression value of 7 (out of 10). You can squeeze it a bit tighter, but at greater and greater expenditures of time. > I made a .zbm of the resultant 2.9 something MB BMP. > My .ZBM was 96,501 bytes. > It took 12 SECONDS to convert and display !! > > 'Ya want a copy ? No thanks... if I was going to use a highly compressed, specialized graphics format that only a few people could view, I'd use bzipped xpm which gives a file size of 65,680 bytes. (also lossless, but at least readable by GIMP, if nothing else) Did you know that *.bmp is "Windows Bitmap" format? Gates decided that bitmaps cost a lot of hard drive space, but no decoding time. Since hard drive transfer was a lot faster in those days than graphics decoding, Bill Gates decided to load the hard drive instead of the CPU. Frankly, I'm surprised you'd want to do things "the Bill Gates way!" ;-) Granted your .zbm idea has certain limted advantages, but I think those are far outweighed by the disadvantages. The first problem with *.bmp files (and thus *.zbm files) is that they're not generally an internet supported format. That means people running Netscape and yes, even MSIE, CANNOT see *.bmp files in their browsers... so using *.bmp cuts out over 99% of the browser world right off the bat. (at least NS 3.04 & 4.76, MSIE 4.0, and Amaya 4.2.1 test negative on natively displaying *.bmp's) So, by using *.zbm, you not only limit your audience to people running Arachne, but further, to only people using Arachne who've made the necessary changes to their mime.cfg. I doubt there's any such thing as a "perfect" internet graphic format, but some of the advantages of *png (in general) are that it's lossless, not limited to 256 colors, has alpha channels (therefore transparency), gamma corrections, filters, and the ability to load and display incrementally through interlacing. PNG's also have a variable compression algorithm, but unlike jpg, it's not quality that's affected, but compress/decompress times. A smaller download means more CPU cycles to display. Granted, you don't need any of that stuff for just a screenshot (though maybe interlacing would have been nice). Web graphics are more than just screenshots though, and your target audience is wider than just people running Arachne who have tweaked their mime.cfg files. For more than you want to know about png's, see http://www.w3.org/TR/REC-png.html -- Steve Ackman [EMAIL PROTECTED] Glass Host, Arts & Crafts http://www.delphi.com/crafts Metamorphosis Glassworks Page http://twovoyagers.com/metamorphosis
