  Photography usually requires optics in conjunction with a recording device
(an image sensor). Eliminating the optics could lead to new form factors for
cameras. Here, we report a simple demonstration of imaging using a bare CMOS
sensor that utilizes computation. The technique relies on the space variant
point-spread functions resulting from the interaction of a point source in the
field of view with the image sensor. These space-variant point-spread functions
are combined with a reconstruction algorithm in order to image simple objects
displayed on a discrete LED array as well as on an LCD screen. We extended the
approach to video imaging at the native frame rate of the sensor. Finally, we
performed experiments to analyze the parametric impact of the object distance.
Improving the sensor designs and reconstruction algorithms can lead to useful
cameras without optics.
