The latest update to Photoshop has just been released--Photoshop CC 2015. Among its new features is a new Content Aware Fill Transparent Areas function when stitching panoramas. It's a mouthful of a name, and it's not one of the headline new features and is really only of interest to niche users, but if you're stitching panoramas in Photoshop it comes in very handy.
The problem it tackles is the empty space you typically get around stitched panoramas that is the result of the perspective and distortion adjustments that are part of the stitching magic algorithms. Up to now, ways of dealing with it have included just cropping it out or manually using a clone stamp or content aware fill. What this new feature does is to automate the retouching. The result is that it can save a lot of time as well as reclaim image area that expands your cropping options.
I've been putting it through its paces, and I must say I'm impressed with how well it works. The results aren't always perfect, and the reclaimed areas often still need some manual retouching, but it gives an impressive head start that can save a lot of time on what is otherwise a very tedious process.
Here's how it works.
Using Content Aware Fill Transparent Areas
The function to create a panorama in Photoshop is handled under the File > Automate > Photomerge option.
The Photomerge options panel will then pop up. It's there that you can choose the projection setting (if in doubt, try Auto first), along with the files that will be stitched together to make the panorama. There are also a few options at the bottom.
This is the result you get from versions before Photoshop CC 2015 with the transparent area around the image. Removing that transparent area meant doing manual cloning (or content aware cloning, manually), rotating, and cropping.
It's easily enough simply to remove it with some straightening and cropping, but that ends up limiting the amount of usable image you have. In this example, the perspective from a longer lens if pretty flat and there's a fair bit of overlap between frames. But when using a wide-angle lens with less overlap between frames you can end up with big dips at the top and bottom that limit the usable part of the image even more unless you want to do a significant amount of retouching.
Here's a much more dramatic example with handheld shots of a very wide-angle lens, taken at the top of the Acropolis at the Maya ruins of Ek'Balam in Mexico.
But there's a new option on the Photomerge options screen. At the bottom, you can check the Content Aware Fill Transparent Areas. This is a really quick and convenient way to expand the usable part of the image.
For this example (a shot of the Austrian National Library at the Hofburg in Vienna), I've used exactly the same files and exactly the same options as above, with one exception: I've checked the Content Aware Fill Transparent Areas option.
The inner line of ants shows the original merged areas. The area outside of that is all the result of the content fill.
It does a remarkably good job. Even if the result isn't always perfect and you have to do some further touchup work or crop out some edges, it does allow you to reclaim areas of an image that would otherwise limit your options. This photo obviously needs a bit of straightening, but I've left it as is to illustrate what fill function does.
If I zoom in on the bottom left, you can see it's done a good job of extending the car, even adding the front of a door handle properly. Things are a bit off when you get to the very left edge, but it still allows more flexibility in cropping.
There are some oddities in the bottom right, where the parked car is partially cloned a couple of times, so that would need some cropping or fixing, but it's pretty easily fixed with some manual retouching.
The sky in the top left is easier, but it's still done a nice job of it without any visible join marks. It's also extended the building to the left very well.
The bottom center area is also a relatively easy section to fill, is also done nice, with the no parking sign naturally extended down and no visible join marks.
And here's the same Ek'Balam panorama. This first version is without the Content Aware Fill option.
And this second one has the Content Aware Fill option enabled.
Again, it's done a remarkably impressive job, even if there are areas that aren't perfect. There are still spots that will need some manual retouching, but it has reclaimed a lot of usable image area and given a great head start. Even the very difficult area of the thatched roof, which has a lot of detail and lines to match up, is surprisingly good.
Although it's very much a niche feature, this is a very handy automation that can really speed up one tedious part of the workflow of stitching panoramas.
It's going to be more effective on some images than others--that's just the nature of the "content" part of "content aware"--it's going to vary based on the original content it's working with. So your mileage is going to vary from image to image. But when it works, it works remarkably well.
Lightroom got its own new panorama stitcher recently that builds on the foundation of Photoshop's, but for now at least the Content Aware Fill option is only available when stitching the photo through Photoshop CC 2015 itself.