You may have noticed that Icon-o-Matic’s File menu includes a „Dump Icon“ option. Selecting this item creates an icon data file at /boot/home/Bitmaps.h This file is of interest only to developers. The large and small icons are dumped into separate contructs:

Large: const unsigned char kLargeIconBits[]
Small: const unsigned char kSmallIconBits[]

NOTE: Multiple dumps appear to accummulate in this file, so you may wish to clear it as needed. The dumped icons may be copied to a new file and #included in your project to be used at will 🙂
Hope this helps you as much as its helped me.