(Quick Question) UITableViewCell background image - maintaining resolution for retina graphics

I have a UITableviewCell that loads its background from an image, my question is, how do i maintain resolution for the retina display?

Do i have two of the same image in the project, such as...

• CellBackground.png
• CellBackground@2X.png

And Xcode will identify to use the second image if the device is iPhone 4?

or do i just include the o开发者_JS百科ne image at Retina resolution and Xcode will "shrink" the image to pre-Retina display?

Thanks

You should include the two images CellBackground.png and CellBackground@2x.png. Non-retina display iPhones have more limited RAM and processing power. Xcode doesn't shrink any images for you, so not including a non-retina image would force older phones to scale the background image from the higher resolution retina display image. This can only hurt your scrolling performance.