July 14, 2014
You will not find a lot of pictures of me. Sure, my family has some, but that is about it. I have always felt rather uneasy with the idea of someone “capturing” my image, although not really out of any superstitious notions of “soul stealing” or any nonsense like that. They just make me really uncomfortable, and so I avoid them as best I can. I make the occasional allowance for various events of import, but I never enjoy it. Its why this latest trend of “selfies” confounds me so much, as I cannot imagine desiring to take one’s own picture so badly – not to mention so often – although that may also have something to do with me rather quickly turning into an old man or something.
Still, despite all of my hang-ups regarding photography, I admit that being skilled at it takes a lot of work. There is much more to being a photographer than just owning a camera, just like there is more to being an artist than owning a paintbrush and some oil paints. Photography is an art in its own right, and within the scope of that art is the understanding of how to make light work for the image you are trying to capture.
In light of that (forgive the unintentional pun), MIT and Cornell University researchers have developed small, light-equipped autonomous drones that are able to automatically assume positions needed to produce lighting effects for a photographer via a rather simple and intuitive camera-mounted interface. Using the interface, the photographer chooses where they would like the lighting to be and the small, helicopter-like UAV (unmanned areal vehicle) flies into position. From there, it is automatically able to maintain the specific lighting conditions desired, compensating for the movement of the photographer, the subject, or other possible variables. The camera itself supplies the drone with the control signal it needs to make these adjustments, sending images to the computer – roughly 20 times per second – running the drone’s control algorithm which then evaluates the lighting conditions and makes adjustments as needed.
Researchers set the drone to do what is known as “rim lighting” for a demonstration. Rim lighting is a lighting technique in which only the edges of the photographer’s subject are illuminated. Why? Because this is considered a very difficult thing to pull off and they wanted to show that their drone could do it. According to Manohar Srikanth, a senior researcher at Nokia who worked on the system as both a graduate student and postdoc at MIT, “It’s very sensitive to the position of the light. If you move the light, say, by a foot, your appearance changes dramatically.” Being able to pull it off, as it did, was a huge step forward for the project.
Interestingly enough, this amazing innovation uses a relatively simple algorithm compared to what one might expect from such a process. Initially, it was believed that the design team would need a very complex algorithm that would take the whole silhouette of the subject and determine its morphological properties, edge curves, and more, but in the end it was really much more simple than that. The algorithm just looks for the most dramatic gradations in light intensity across the whole image, measuring their width. In the case of the rim-lit subject, most of these congregated around the same value which the algorithm took to be the width of the rim, allowing to to make its needed adjustments. Even with using this much simpler method, the UAV is able to keep up with the movements both of the subject and the photographer, all while maintaining its determined lighting condition, even when that is something as complex as rim lighting.
All in all, an incredible contribution to the field of photography, proving that drones have a multitude to uses that some of us might have never before considered.
Image Credit: Manohar Srikanth, Frédo Duran, Kavita Bala