Converting stock .png graphics
intel Mac & PPC
For whatever reason, the pngs on the iPhone have some additional data in them that prevent the end user from just opening the graphic
and editing it. Apple also skews the color channels on the pngs. To be able to modify these pngs, you must use a program that can
convert them to a usable state. It's my understanding the pngs are modified like this to make it easier/quicker for the iPhone to
process and render.
If you try to view stock graphic files in the firmware, you'll see they refuse to display.
I found this great program at the DWBlog
that not only converts the .png into a usable format, but also corrects the color skewing.
You can download the program here.
When you've decompressed the file you will be left with a folder that looks like this.
Put the .png you want to convert into this folder.
Go to your Applications/Utilities folder and launch the application called Terminal. Assuming you saved
the downloaded program on your desktop, enter the following commands:
./iPhonePNG icon.png (or the name of your .png)
It will decode and convert the .png immediately.
It will place the converted .png into the same folder as your original.
And here it is, a completely editable image. You do not need to do anything fancy to put this graphic
back onto the iPhone, other than making sure it stays in .png format.