Light, reflected from surfaces, arriving the imaging plane of a camera, must be interpreted to be useful to a perceiving system. This interpretation is a process of inference from ambiguous and incomplete measurements using experience and knowledge. The Perceiving Systems Department is focused on uncovering the mathematical and computational principles underlying this process. This means understanding the statistics of the world (its shape, motion, material properties, etc.), modeling the imaging process (including optical blur, motion blur, noise, discretization), and devising algorithms to convert light measurements into information about the 3D structure and motion of the world.