Figure 1
From: Tracking objects outside the line of sight using 2D intensity images
Tracking objects around a corner.
(a) Our experimental setup follows the most common arrangement reported in prior work, except that it does not use time-of-flight technology. A camera observes a portion of a white wall. To the right of the camera’s field of view, a collimated laser illuminates a spot that reflects light toward the unknown object. The light distribution observed by the camera is the result of three diffuse light bounces (wall–object–wall) plus ambient contributions. (b) Geometry of three-bounce reflection for a single surface element. (c) Flow diagram of our tracking algorithm. Given shape, position and orientation of an object (the “scene hypothesis”), we simulate light transport to predict the distribution that this object would produce on the wall. By comparing this distribution to the one actually observed by the camera and refining the parameters to minimize the difference, the object’s motion is estimated.
