# iPhone image asset recommended resolution/dpi/format

I'm learning iPhone development and a friend will be doing the graphics/animation. I'll be using cocos2d most likely (if that matters).

My friend wants to get started on the graphics, and I don't know what image resolution or dpi or formats are recommended.

This probably depends on if something is a background vs. a small character.

Also, I know I read something about using @2x in image file names to support high res iphone screens. Does cocos2d prefer a different way? Or is this not something to worry about at this point?

What should I know before they start working on the graphics?

• Step One is to accept answers.. your percentage is pretty low... it doesn't encourage others to answer your questions. – Nate Feb 6 '11 at 20:46

To get even more clear images on the iPhone 4, you can also provide @2x images that are the correct size to match the native iPhone 4 screen. As an example, if you have an image called AvatarIcon.png on your app that's 100 x 50 pixels. You could also create on called AvatarIcon@2x.png that's 200 x 100 pixels. Now you get a crisp image on both the iPhone 3G and the iPhone 4.
• For cocos2d you should use -hd as suffix instead of @2x. So use AvatarIcon-hd.png rather than AvatarIcon@2x.png. Source: cocos2d-iphone.org/wiki/doku.php/… – bummzack Feb 7 '11 at 7:52