Straightening an Image

Often when you scan things, or take pictures, you discover after you see the picture on your screen that you were a few degrees off the horizon. Usually this doesn’t matter, and you can get away with cropping out the edges, and nobody will ever be able to tell.

Some times, however, you aren’t so lucky, and will have to straighten the lines in an image considerably. You might be trying to use the Transform tool, or you might try to rotate the image in another way, but you will find that it can be incredibly hard to completely align an image. This is particularly frustrating if you have a line running along the length of an image; The edge of a building for example. If the line is only a fragment of a degree off, it becomes very obvious.
Luckily, Photoshop provides a useful way to solve the problem