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 you will see in a moment, 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.
First you want to look for something in your image that needs to be straightened, either horizontally or vertically. Then you want to drag along the edge of the crooked item with the Measure Tool so Photoshop has something to work with when trying to figure out how crooked the photo actually is. In this case, I will click and drag horizontally along the roof of the building directly behind Ms. Liberty. Clearly the roof should be entirely horizontal, yet it clearly isn’t at the moment. I’ll click once on the left side of the roof, then drag over to the right side of the roof. This draws a thin line between where I first clicked on the left and where I finished dragging on the right, and Photoshop uses the angle of this line to determine how far the image will need to be rotated in order to straighten it.
So, basically, 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 (it’s the number listed to the right of the letter “A”). In my case, we can see that my line is on an angle of 1.9 degrees:
The Options Bar showing the angle of the line drawn with the Measure Tool. Photoshop will use this angle to figure out how far it needs to rotate the image in order to straighten it. Choose The “Rotate Canvas – Arbitrary” Command Click on the Image menu at the top of the screen, choose Rotate Canvas, and then choose Arbitrary:
Go to Image > Rotate Canvas > Arbitrary. Funnily enough the word “arbitrary” is defined as “random or by chance”, yet that’s precisely the reverse of what we’re doing here. This is not random rotation; we are not leaving anything to chance. The Measure Tool has been used to find out precisely what angle and how much our image needs to be rotated by: now Photoshop can use the measurements we’ve given it to level our image without any guess work. As you probably are already aware, much of the problem with learning Photoshop comes from understanding the terminology, and in this particular case, I don’t know what Adobe was thinking.
However, life goes on. Once you select “Arbitrary”, Photoshop pops up the Rotate Canvas dialog box, and as we can see, all the work has already been done for us. In my case, Photoshop has already entered a value of 1.85 for the Angle option, and it even knew that the image will need to be rotated counter-clockwise, which is why the CCW option is also selected:
Photoshop Tutorials: The “Rotate Canvas” dialog box with the angle and direction already selected for us. You might be curious as to why Photoshop entered an angle of 1.85 when the Options Bar showed an angle of 1.9 just moments ago. The reason behind this is that Photoshop rounds off the angles in the Options Bar to 1 decimal place, so it showed 1.9 even though the angle of the line we drew with the Measure Tool was actually 1.85. The angle shown in the Rotate Canvas dialog box is the correct angle.
At this point we simply need to click “OK” in the Rotate Canvas dialog box to exit out of it and have Photoshop rotate and straighten our image automatically for us. You should notice that the image has now been rotated and straightened. Everything looks great and fortunately the Statue of Liberty is no longer leaning to the right. Thanks to the Measure Tool and the Rotate Canvas command we were able to straighten the image perfectly without any guess work.
You might notice that there is a minor problem. When we rotated the image inside the document window we created some blank white canvas areas around the outside of the photo. We will want to end things up off by removing those areas using Photoshop’s Crop Tool. You can select the Crop Tool from the Tools palette, or simply press the letter C on your keyboard to select it with the shortcut:
Using the Crop Tool click near the top left corner of your image and drag down towards the bottom right to create a border around the area of the image you want to keep. You can fine-tune your selection by dragging any of corner handles or by dragging the top, bottom, left or right sides of the selection:
Use the Crop Tool to drag out a selection around the part of the image you want to keep. Once you’ve dragged out your cropping border, press Enter (Win) / Return (Mac) to have Photoshop crop the image.
