Join Tim Grey for an in-depth discussion in this video Correcting perspective, part of Restoring Photos with Photoshop CS6.
Older large format cameras had perspective correction essentially built into them and yet you'll find that there are plenty of older images that could still use a little bit of correction when it comes to perspective. For example, you can see here the building doesn't exactly look to be square. Obviously we're seeing the building from a bit of an angle, but still it seems like it's leaning a little bit away from us and that's something that we can correct relatively easily in Photoshop. We actually have a Perspective Crop tool available within Photoshop CS6 or a perspective Option with the Crop tool in previous versions. But I find that that's a little bit limited and also, it doesn't quite give us as much flexibility when it comes to a nondestructive workflow. And so I prefer to work with the transform commands in most cases when I need to correct perspective in a photo.
I'll go ahead and start off by creating a background Copy layer. I'll drag the Thumbnail for the Background Image layer down to the create New Layer button, the blank sheet of paper icon, at the bottom of the Layers panel. Now we'll create a Background Copy layer, which I'll transform in order to correct perspective. First though, I want to view a grid over the image. So, I'm going to Choose View, and then Show followed by Grid. That will display a grid that I can use as a reference to make sure I'm aligning all elements of the image as I desire. I'll then go to the Edit menu and I'm going to Choose Free Transform and that gives me quite a bit of flexibility in terms of stretching and skewing this image around a bit.
I'll zoom out just a little bit so that we can see more of the image and what I'm going to do is adjust individual corners of the photo. To accomplish that I'll hold the Cmd key on Macintosh or the Ctrl key on Windows so that I can drag a corner of the image without affecting other corners in the photo. I'll then drag a corner, in this case the top left corner into position so that elements of the image that should be perfectly vertical are perfectly vertical. Now I'll need to make a bit of a decision in some cases because I can't necessarily get all elements perfectly aligned. But the idea is to get things looking as close to perfect as possible. I think I'll adjust that top left corner outward just a little bit. What I'm doing is essentially trying to balance the difference between the leftmost edge of the far building, and the right corner of the foreground building, trying to get them both as close to perfect as possible. I can also adjust the top right corner of the image, you can see I can adjust effectively the back edge of the building, but really paying attention to the entirety of the building, trying to make sure that I'm achieving a nice square result.
And I can continue in this manner, adjusting all four corners as I see fit based on the adjustments that are necessary within the photo. You want to pay careful attention to that grid and evaluate multiple areas of the photo in order to make sure that you're getting the best result possible. So, I'll continue fine-tuning here, and that's looking to be a pretty good adjustment. I'll go ahead and turn off my grid so that I can see the image all by itself. If I needed to, I could also hold the Ctrl or Cmd key and drag one of the center anchor points, in this case, the top center anchor point, in order to effectively lean the image overall. And I think in this case I need just a slight bit of adjustment there, maybe drag this a little further over to the right.
But then take that top left corner up, and over to the left just a hair. Again trying to balance all of these adjustments so that I end up with a result that looks appropriate, in terms of prospective. I'll bring that top-right corner over to the left just a hair, and that looks to be a pretty good result. Again, I can view that grid, I can choose it either from the menu, or I can press, Ctrl, apostrophe on Windows or Cmd apostrophe on Macintosh, at any time to view or hide that grid. Once I'm happy with the result, I;ll go ahead and click the Commit button, that checkmark icon on the options bar. I can then turn off the background copy to see the original image, and then turn the visibility for that layer back on to see the after-version of the image. You might notice though, that because of the distortions I've applied, I now need to crop the image.
So, I'll Choose the Crop tool, and then I'll adjust all four corners of my crop so that all four of them fall inside the adjusted area of the image. In other words, inside that Background Copy layer. In this case I think I can crop a little bit more tightly than that, which will both help make sure that I don't miss any areas, but also just tighten up the overall composition here. I'll then make sure that the delete cropped pixels check box is turned off, so that I'm applying a non-destructive crop. And then I'll click that Check Mark button to commit my crop.
So now you can see that I have my background copy that has been straightened but has also been cropped. So, you can by turning off the visibility for that Background Copy layer and then turning it back on we've got a much improved image in terms of perspective.
- Choosing your source image
- Adding metadata
- Image restoration strategy
- Working with layers
- Evaluating before and after
- Tonal and color adjustments
- Image cleanup
- Adjusting detail
- Saving the master image
- Creating a print or online version