Photoshop’s Content-Aware Crop Tool for Underwater Photography

By Joseph Tepper

It’s not often that we see a new tool in Photoshop that really appeals to underwater photographers. But the brand new “Content-Aware Crop” tool is something that every underwater photographer should know how to use, as it can save a significant amount of time by streamlining the cropping process.

What Is Content-Aware Crop?

Introduced in the 2015.5 Version of Photoshop Creative Cloud (June 2016), the Content-Aware Tool automates a process photographers have long had to do manually—filling in empty space after cropping.

This typically happens when you’re trying to fix a horizon line in an image. By rotating the image, while keeping the same crop, you will create empty spaces around the edges. You would then need to go in manually and fill in these empty spaces with a combination of the clone brush or existing content-aware tool.

Alternatively, Photoshop introduced a default setting so that the Crop Tool was set to “Snap To” the edges of the document. The problem with the “snap to” element is that it automatically scales down the crop so that the entirety of the image fits within the boundaries. This can be detrimental, as it will automatically crop out negative space—or worse, part of your main subject.

Although you can straighten and rotate images with the standard “Snap To” crop, it does automatically scale the image to fit—which cuts off the front of the kayak in this image

Content-Aware Crop eliminates the often-annoying snap feature, while automatically filling in the empty spaces in the image. This can be used minimally to fill in edges when straightening an image. Or, it can also be used to add more room to a cramped image.

With Content-Aware Crop, you can straighten the image without cutting off any portion of the kayak: The tool automatically fills in would-be blank spaces (shaded red)

Straightening an Image with Content-Aware Crop

Having a horizon line that is parallel to the bottom of the frame is a classic rule of photographic composition. While we don’t have typical horizons, there are certain occasions when it’s important to have lines not running at an angle through the frame.

However, underwater photography is not landscape imaging—we don’t have a tripod to set up and take our time to consider lines in our images. Mistakes happen, whether it’s the rush of a big animal encounter at the surface or a rogue wave that disrupts the still water during a split shot. And so, there’s sometimes a need to straighten an image in post-processing.

The easiest way to do this is to use the “Straighten” tool in Photoshop. Combined with the new Content-Aware Crop, you can fix a crooked horizontal line in just a few seconds:

Step 1: Begin by selecting the Crop tool. In the options bar at the top you’ll want to select the Straighten symbol.

The original image has the water line and horizon line of the sand rather crooked

Step 2: Make sure you have Content-Aware selected, and then draw a line across the horizon line you want straightened (in this case, the water line).

Make sure to have the “Content-Aware Crop” option turned on

Step 3: The tool will automatically straighten the image to make the horizon straight, while filling in the blank areas with generated imagery.

Final image: all fixed in a second!

Adding Space with Content-Aware Crop

Another reason to use the Content-Aware Crop tool is to add more space to an image. This is especially important with fish photography: Getting close to your subject is great, but having no negative space in front of the animal isn’t. This can lead to a feeling that the subject is trapped in the frame, almost like a fish tank.

Here’s how to use the Content-Aware Crop tool to add more space into an otherwise cramped image:

Step 1: Begin by selecting the Crop tool, and making sure that you maintain the same ratio as in the original image. The crop box will surround the image.

This original image is too tight on the front of the fish, making it feel cramped

Step 2: Make sure you have Content-Aware selected, and then drag the corner or the side where you want more space.

The more space you add, the larger the portion of the image that needs to be generated—so don’t push it too far

Step 3: Just by cropping the way you envisioned the frame to look, the Content-Aware Crop tool will generate imagery to fill the negative space.

The final image gives more space and compositional balance between subject and negative space

Limitations of Content-Aware Crop

Like the original Content-Aware tool, the hybrid Content-Aware Crop tool has its limitations. It can really be a time saver for a large majority of images where you need to straighten or add space. But remember that the program is effectively generating new graphics to cover the empty spaces.

As a result, it will work best in areas with consistent colors and patterns—like sand, water, or rocks. Here, it will be able to extend the negative space quite effectively. You may want to go in and use the Spot Healing Brush tool afterwards to make sure everything looks acceptable.

But don’t expect the Content-Aware Crop to be able to generate cut-off fish tails, fins or any other unique compositional element of your image! It’s a great tool—but you need to use it responsibly.

Content-Aware Crop isn’t a magical fix. Trying to add more space to the right side of this complex image ended up creating a massive shark blob!