Providing image assets for iPhone projects

GUI assets for the iPhone should be delivered according to the following specifications:

Images

• The screen resolution of the iPhone is 320x480, the retina screen of the iPhone4 and iPodTouch has a resolution of 640x960.
• All image files should be in PNG
• If there should be support for the iPhone4 retina screen, all PNG files have to be delivered in 2 resolutions:
  • Standard-resolution for non-retina screen (iPhone3G, iPhone3Gs)
    • [filename].png (e.g. 100x100px)
  • High-resolution for retina screen ( iPhone4 ), which is 4 times the standard-resolution. "@2x" should be added to the filename:
    • [filename]@2x.png (e.g. 200x200px)
• Start-screen should be named Default.png for iPhone and Default@2x.png for iPhone4 with a resolution of 320x480 and 640x960 respectively.

More information can be found in Apple's iPhone Interface guidelines.

Internationalization

GUI assets that should be displayed in multiple languages, following convention applies:

Files need to be located in the respective language folder. E.g. for an English and German internationalization, assets should be put into two folders "en.lproj" and "de.lproj".

• en.lproj/
  • Img1.png (English version of Img1)
  • Img2.png (English version of Img2)
• de.lproj/
  • Img1.png (German version of Img1)
  • Img2.png (German version of Img2)

Application Icon

The icon file has to be named "Icon.png" and should be provided in 3 resolutions. (depending on devices that should be used)

• Icon.png - 57x57 pixels application icon for standard resolution iPhone
• Icon@2x.png - 114x114 pixels application icon for high resolution iPhone 4 (if needed)
• Icon-72.png - 72x72 pixel application icon for iPad (if needed)

More information can be found on Apple's App Icon Technical Guide

-- SupportMetaio - 2010-10-28