Question

I have just started designing for my first iOS app and I am confused to which type of .PNG of file I need to use or if it matters at all. I am using Photoshop and Illustrator to make my images. Do I “Save for web and devices” as a PNG-24? Or do I “Save As” a .PNG? I have looked a lot of places and can’t find much documentation.

Answer 1

Here’s a resource for you:

http://bjango.com/articles/pngcompression/

To make it short:

For all images and icons, the PNG format is recommended (avoid using
interlaced PNGs). The standard bit depth for icons and images is 24
bits (8 bits each for red, green, and blue), plus an 8-bit alpha
channel. You do not need to constrain your palette to web-safe colors.
Although you can use alpha transparency in the icons you create for
navigation bars, toolbars, and tab bars, do not use it in application
icons.