There are many reasons that you might want or need to rotate an image. If you have a scanned picture or a digital camera image that should be vertical but opens as a horizontally oriented picture, rotating it 90 degrees corrects the problem. This is a common occurrence when you use a scanner because it's usually quicker to scan with the picture horizontal, regardless of its normal orientation (see Figure 4.5).
Figure 4.5. Placing the short side horizontally shortens the scanning time.
If you have used a much ...