How can I generate iOS/Flurry style icons in OS X? As some of you might know, the iOS treatment of app icons is ruthlessly strict. It forces a certain roundness of the corners and allows no transparency, hence enforcing a unified look. I think that's nice.

I recently fell in love with Iconfactory's Flurry icon set and making new icons in that style made me think; what's the easiest way of applying a mask and an overlay on a custom image, and generate all sizes needed for a complete OS X icon file (icns)?

As mentioned below I'm not looking for technical explainations of how iOS generates its icons, nor a system wide solution for generating icons on the fly. Just what's mentioned in bold above. I'm also aware of the IconBuilder approach and although it's a great tool, it's not what I'm asking for. I'd prefer a drag-and-drop interface of some sort.
Perhaps if someone wrote a hack (but I remain skeptical as all this could be easily done by getting the icon's template (PSD file) and doing it manually.

iOS has a framework in place to deal with SpringBoard icons. The files are as follows (naming convention taken from iOS 5. Previous iOS versions drop the ~iphone suffix):


AppIconMask@2x~iphone.png
AppIconOverlay@2x~iphone.png
AppIconShadow@2x~iphone.png


(1) is the clipping mask, that dictates the shape of the icon. (2) is the "gloss" effect that has somewhat fallen out of favor in the past couple of years and is optional. (3) is the base of the icon, the shadow that is applied under the final product.

I made a graphic and accompanying explanation of how they all work together on my website which should help better explain how iOS delivers icons on its respective device.



OS X has no such system in place. Each icon is simply constrained by the dimensions set in Finder. Apple never sought to control the way icons look on OS X, but wanted to have a uniform appearance on iOS (and I don't blame them), hence the reason why they developed such a framework.

You could try contacting a Cocoa developer on porting the MobileIcons.framework from iOS to OS X, but again, because Finder can adjust sizes (in Lion, anywhere from 1024x1024 on down), I remain skeptical that it at all possible.