Straighten Crooked Photos Using the Measure Tool

I have found the best way to straighten images in Photoshop is to use the Measure Tool, which fortunately takes all the guess work out of the process. As long as you have something in the photo that needs to be straight, Photoshop will do almost all of the work for us!

The Measure Tool is hidden behind the Eyedropper Tool in the Tools palette and you'll need to click and hold your mouse button down on the Eyedropper Tool for a second or two. A fly-out menu appears and shows you the other tools hiding behind it. Click on the Measure Tool to select it.

To straighten something all you need to do is click and drag with the Measure Tool along the edge of something in the photo that should be straight horizontally or vertically. You can look up in the Options Bar at the top of the screen and see the angle of the line you've just drawn

The Options Bar should be showing the angle of the line you have drawn with the Measure Tool. Photoshop now uses this angle to find out how far to turn the image in order to straighten it. To find the “Rotate Canvas - Arbitrary" Command
Click on the Image menu at the top of the program, choose Rotate Canvas, and then select Arbitrary.

Once you click on "Arbitrary", Photoshop pops up the Rotate Canvas dialog box,
then all we need to do is click on the OK button in the Rotate Canvas dialog box to exit and have Photoshop rotate and straighten the image for us.

Take a look at this Video from You Tube about Straightening Photos