It happens to the best of us. You take a few shots, but the one where the subject looks, hands down, the best isn’t framed the way you’d like it to be. There are a few tricks you can use to add to the background, and we’re going to discuss one that involves Content-Aware Scale in Photoshop. PiXimperfect has created a YouTube video to demonstrate exactly how you can use Content-Aware Scale to extend your background.
[Rewind:] Upsampling With Adobe Photoshop CC 2018’s Preserve Details 2.0
It should be noted that this technique won’t work flawlessly with all types of backgrounds. The best environments to easily allow a lot of stretching with Content-Aware Scale are going to be relatively plain and without prominent verticals if extending horizontally as shown. The beach shots used in the demo are a perfect example of the type of photo with which this will play nicely. 
Once you’ve got your photo with a background that will cooperate loaded into Photoshop, here’s what you do:
- Use the crop tool to change your canvas to the desired dimensions. Be sure to use the “clear” button to clear the ratio so that you can adjust freely, or if you know the exact dimensions you need you can enter them into the dimension boxes.
- Use the Content-Aware Scale tool to stretch your image, paying close attention to the subject. Once you see the subject begin to widen, un-stretch the photo until the subject is unaltered and use the enter key to accept the scale.
- Use the Content-Aware Scale tool again, once more keeping a close eye on the subject to avoid any distortion. Accept the scale before the subject begins to stretch. Repeat as necessary.
- If one side of your image stretches more readily without distorting the subject than the other, but you need to extend both sides, you can use the marquee tool to select a portion of your image that does not contain the subject and apply Content-Aware Scale to only that portion.
- You may find that the Content-Aware scale tool has caused some artifacts in your background. If this happens to your image, you can use Photoshop’s various clone/heal options to remove them.
Check out PiXimperfect’s video below to see these steps performed!