Force UITabBarItem's image to a specific size

I 开发者_开发问答have a UITabBarController, initialized by a xib file. all it's view controllers are initialized by a xib file as well. In apple's HIG it is specified that a High-resolution tab bar icon should be approximately 60x60. I have a set of 52x52 icons, and I used them as the image for the tab items. but for some reason, it displays them as if I'm using a none-high resolution screen - they're off the bounds of the tab bar item, and are pixelized.

How can i set a "fixed" size for the icons so this will be avoided, and how can I, using Interface builder, choose different tab bar images for low-resolution and high-resolution screens?

Tnx in advance!

What names are you using for these images?

What you usually have to do is have the standard image named xxxx.png and the high resolution retina display image named xxxx@2x.png

When you use these images in interface builder, use the standard image, the system will look for that filename with "@2x" if it's being executed on an iPhone 4.