Is there an easy way to straighten images?

[Doom]

Usually since eyeballing it is horribly wrong I have to add another layer with a couple lines so I can make sure it's straight. How do the pros straighten their images?

[antony30bc]

Snow had a neat trick using the ruler tool in Photoshop. You draw the ruler out on what should be a straight line, then go to rotate - arbitrary and it will pre-populate the rotate amount by what is required to make the ruler straight.

I also have used the Guides in Photoshop to setup 2 vertical and 2 horizontal guides along the edges then rotated little by little until it was the closest to square I could get.

I confess I havn't always done this though, sometimes if it looks straight enough I just leave it.

I am also curious what other tricks are out there.

Antony30bc

[tiktektak]

The "trick" with the measurement tool works very nice....

Just take your scan. Use the measurement tool. Draw a line from one edge to the other of the cover scan(NOT diagonal but horizontal or vertical). Go to -> Image -> rotate canvas -> arbitrary and voila the Image will be perfectly straight(at least on the side you used your measurement tool on)

It can always happen though that another side of the scan isn't perfectly straight even after using the trick. I suppose that is because covers often aren't perfect squares....

Regards Seb