Background image is not fitting properly iPhone

In my application i am using background image programmatically like below

self.view.backgroundColor =[UIColor clearColor];

self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"homeScreen.png"]];

I have tried both image sizes 320x480 pixels and 640x960 pixels with name of @2x. but both images are not fitting properly into iphone simulator.

Do开发者_JS百科 i need to reduce navigation bar area from 320x480? then it will fit?

I was wondering why?

320 x 480 and 640 x 960 are fullscreen resolutions. if you have a status bar visible remove 20 pixels etc.

Carrier Status bar = 20 high UINavigationBar = 44 high UITabBar = 49 high UISearchBar = 44 high UIToolBar = 44 high