As explained by Akkaynak and Treibitz, “An underwater photo is the equivalent of one taken in air, but covered in thick, colored fog.” And while the precise effects of water on images is somewhat technical, it doesn’t take much to recognize that water degrades images, causing a loss of both clarity and accurate color.
Enter Akkaynak’s Sea-thru algorithm, which is designed to remove color casts and other optical problems created by water. In other words, it can be applied to an underwater photo, one that’s blue (with inaccurate colors), and turn it into something that looks like it was taken on land.
For examples, check out the images in the Scientific American video:
How it works
But how was the algorithm actually developed, and how does it work?
Basically, Akkaynak took a series of underwater photos, making sure to place her color chart into the scene for an accurate reference. She ultimately compiled over a thousand images in several environments. From the reference images, Akkaynak and Treibitz developed a model that takes into account the unique ways that light interacts with water in order to correct underwater images for color and light.
Now, Akkaynak and Treibitz had academic purposes in mind when they conducted this research. The algorithm, as presented in the original research paper, is meant to “help boost underwater research at a time when our oceans are increasing stress from pollution, overfishing, and climate change,” by giving researchers better access to visual data from underwater cameras.
But it’s easy to see how the Sea-thru algorithm could be relevant to underwater photographers everywhere. If Sea-thru can make photos become more accurate and (often) more vivid and colorful, might underwater photographers like to use it on their own images?
On the other hand, there’s the question of whether the best underwater photos convey an authentic sense of the (underwater) environment. Without the blue tones of water and the haze that water provides, photos may lose the sense of wonder that comes from doing work under the sea.
So let me ask you: Do you prefer underwater images where the water is much less apparent? Or do you like more authentic underwater photos, color cast and all? Would you be interested in the Sea-thru software?
Share your thoughts in the comments!