Why doesn't icon composer 2.4 support the 1024x1024 size icon any more?

The icon composer 2.2 in Xcode 4.3.3 supports the icns of 1024x1024. However, for icon composer 2.4, it doesn't support that any more. This is ironic, since Apple pushes for the retina display mbp and requires the newly submitted app to use 1024x1024 icon, but the icon composer doesn't support it any more.

Is there any alternative or newly introduced solution by Apple for creating the icon of the size 1024x1024? I really don't understand why Apple is doing this.

Thanks!

Icon Composer 2.4 doesn't support 1024x1024 size icons anymore because the workflow for creating application icons for Mac or iOS apps has changed.

See the Provide High-Resolution Versions of All App Graphics Resources section of the High Resolution Guidelines for OS X.

The new workflow is as follows:

1. Create a folder with the .iconset extension (for example MyApp.iconset)

2. Place .png files with each files size:

   icon_16x16.png
   icon_16x16@2x.png
   icon_32x32.png
   icon_32x32@2x.png
   icon_128x128.png
   icon_128x128@2x.png
   icon_256x256.png
   icon_256x256@2x.png
   icon_512x512.png
   icon_512x512@2x.png

3. Convert this .iconset directory structure to a .icns file. There are two options:
   • Drop your new .iconset folder into your Xcode project and use this as your Application icon.
   • Use iconutil -c icns -o myicon.icns myicon.iconset in the Terminal (no need to install XCode).

After doing this, everytime you build Xcode will compile your .iconset folder into a .icns file and use that in your application bundle. This has the distinct advantage of treating your application icon as a set of 'source images' from which the .icns file is derived.