makeiconset.pl is a short Perl script which creates a .iconset folder for Mac OS X apps, post-Retina, containing the required ten (10) png files of different sizes. It simply scales down a given png file, using the 'sips' program built into Mac OS X. This script is therefore useful for simple, straight-line icons which don't need to be tweaked for each scaling by a human designer, or for projects where the intended users and budget does not warrant it. Or, you can run this script, examine the results and then hand-tweak the ones which are not good enough.
To use it makeiconset,
where <source> is the path to a 1024x1024 pixel png file
The .iconset product directory is created in the same directory as this source file. The product is named <basename>.iconset, where <basename> is the basename of the source file, without the .png extension. If such a folder already exists, it is deleted and the product replaces it.
(You then add the .iconset folder to the .app target in your project. Xcode 4.4+ will compile it into a .icns file when building, and include the .icns file into your app product's package.)
Visit this project's GitHub Repository to download, fetch, or clone this code.