Using Computers To View The Unseen

Images in this blind light transport factorization example are projected onto a wall behind the camera. A group of scientists from MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL) has developed a method that can reconstruct, using no special equipment, hidden video from the subtle shadows and reflections on an observed pile of clutter. With a video camera turned on in a room, the scientists can reconstruct a video of an unseen corner of the room, even if it falls outside the camera's field of view. By observing the interplay of shadow and geometry in video, the team's algorithm predicts the way that light travels in a scene, which is known as "light transport." The system then uses that to estimate the hidden video from the observed shadows -- and it can even construct the silhouette of a live-action performance.