Talk:Apple Icon Image format

Tiger icons

Doesn't Tiger add support for 256 x 256 icons? The Geeklord 21:59, 17 April 2006 (UTC)

I haven't seen that. I would be thrilled if they did. Dread Lord CyberSkull ✎☠ 23:09, 17 April 2006 (UTC)

See Mac OS X 10.4 Tiger which states:

Apple has quietly expanded the maximum supported dimensions of Mac OS X's "icns" icon format to include 256x256-pixel icons, and 512x512-pixel icons are not out of the question for the future.

"Scalable User Interface" By John Siracusa, Published: April 28, 2005

There is some evidence that no 256 x 256 icons have been seen in the wild. Leopard has support for 512 x 512. Both of these sizes of icons appear to depend on "Icon Services" to read or write their data, and the interested reader should search for kIconServices256PixelDataARGB or kIconServices512PixelDataARGB . —Preceding unsigned comment added by 81.97.194.106 (talk) 14:47, 25 May 2008 (UTC)

Am I doing this right? (OS X Icon Editor link)

Newbie editor here...I added the external link to the OS X Icon Editor page because it seems relevant and is one of the few freeware icon-editing resources available for OS X. (All of the See Also links are commercial products.) Is that the correct usage? Perhaps it ought to have its own Wikipedia article, but I haven't the time right now, and I'm not sure if it's sufficiently notable anyway. Phasma Felis 00:17, 28 July 2007 (UTC)

Is there actually a 256 x 256 icon

See Scaling Your Artwork —Preceding unsigned comment added by 81.97.194.106 (talk) 16:38, 24 May 2008 (UTC)

The Mac OS 10.5 version of Icon Composer has a slot for 256x256 icons. David Arthur (talk) 18:54, 24 May 2008 (UTC)

Developer's Information

See HowToMakeAquaIcons and icns file format specification . —Preceding unsigned comment added by 81.97.194.106 (talk) 16:51, 24 May 2008 (UTC)

Is the run-length compression used in the icns format really PackBits?

I implemented a reader plugin for the icns format, but couldn't read the run-length compressed icons, even though I believe I have PackBits implemented correctly. After googling around, I came across Apace Sanselan, which implementes icns reading and correctly decodes the compressed icons. While similar, that run-length encoding is not PackBits (at least not as described on WikiPedia).

In particular, the length of the compressed runs are defined in PackBits as 1 - n (2-129, smaller n yields larger lenghts, n == -128 is a no-op), but in icns, they seem to be n + 131 (3-130, larger n yields larger lengths).

Is it me, or is it the article that is wrong about PackBits? Confused...

93.124.242.6 (talk) 13:20, 27 October 2011 (UTC) Harald K