In Adobe Photoshop CS4 and newer, you can use Content-Aware Scaling to resize an image without distorting or changing surrounding content like people, buildings, animals, and so forth. Normally, when you scale an image, all of the pixels are uniformly modified. But with Content-Aware Scaling, Photoshop intelligently figures out what’s most important and only resizes those parts that aren’t (grass, sidewalks, water, and the like).
To use this feature:
- Select the photo (or part of the photo).
- On the Edit menu, select Content Aware Scale.
- Click and drag to obtain the effect you desire. Note that there are properties you can change in the properties palette for Content Aware Scale.
For example, here is the original photo of Vincent Van Gogh’s painting of his bedroom:
Original version of Vincent Van Gogh's Bedroom
Here is a version of this painting scaled using Content-Aware Scaling:
Van Gogh's painting of his bedroom scaled using Content Aware Scaling
And here is what the same picture would look like using traditional scaling (using Image>Image Size or Edit>Transform):
Van Gogh's painting of his bedroom scaled using traditional scaling methods
Note the bed, pillows, paintings, chairs, and the objects on the table look relatively normal when using Content-Aware Scaling, but look squished, flattened, and distorted when scaled using traditional scaling methods. Content Aware Scaling keeps the important objects (in this case, the bed, pillows, paintings, chairs, and objects on the tables) looking as they originally did while only resizing the relatively unimportant objects (in this case, the floor and walls).