Cropping a layered document
By Lesa Snider, iStock evangelist and author of Photoshop CS5: The Missing Manual
Normally, when you crop an image, Photoshop deletes the portion of the photo that you cropped so it’s gone forever. But if you’re cropping a layered file, you can tell Photoshop not to vaporize the cropped material, making it easy to get back if you change your mind. To do that, head up to the Options bar and, in the Cropped Area section, turn on the Hide radio button.
From now on, Photoshop will hide the cropped area outside the document margins instead of deleting it, meaning that even though you won’t see it onscreen, it’s still part of your file. In fact, if you want to resurrect the cropped portion, choose Image>Reveal All and Photoshop will automatically resize the canvas to reveal anything that might be loitering outside the edges of the document (in this case, that’s the previously cropped bits).
If you want to bring back a portion of the cropped area, just use the Move tool to reposition that area back into view.