A ninepatch, for those unfamiliar, is described here. In a nutshell, you can take an image and put a few pixels on the outermost pixels to represent which areas should stretch and not stretch when they're used on UI widgets of varying sizes. That's great if the program you're working with knows how to understand a ninepatch style image.
Is there a way to resize something in photoshop in the same way? Normally I would just scale it, but that doesn't work if I want to keep the borders edges a specific thickness and only stretch the center portions.