Angle Sensitive Pixels for Lensless Imaging on Spherical Sensors
Yi Hua Yongyi Zhao Aswin C. Sankaranarayanan
We propose OrbCam, a lensless architecture for imaging with spherical
sensors. Prior work in lensless imager techniques have focused largely on using
planar sensors; for such designs, it is important to use a modulation element,
e.g. amplitude or phase masks, to construct a invertible imaging system. In
contrast, we show that the diversity of pixel orientations on a curved surface
is sufficient to improve the conditioning of the mapping between the scene and
the sensor. Hence, when imaging on a spherical sensor, all pixels can have the
same angular response function such that the lensless imager is comprised of
pixels that are identical to each other and differ only in their orientations.
We provide the computational tools for the design of the angular response of
the pixels in a spherical sensor that leads to well-conditioned and
noise-robust measurements. We validate our design in both simulation and a lab
prototype. The implications of our design is that the lensless imaging can be
enabled easily for curved and flexible surfaces thereby opening up a new set of
application domains.