Angle Sensitive Pixels for Lensless Imaging on Spherical Sensors

TL;DR

The paper introduces OrbCam, a lensless imaging system using spherical sensors where pixel orientation diversity enables robust, invertible imaging without modulation elements, validated through simulation and lab prototypes.

Contribution

It demonstrates that spherical sensors with identical pixels differing only in orientation can achieve invertible lensless imaging without modulation elements, simplifying design and expanding applications.

Findings

Spherical sensors with oriented pixels improve imaging conditioning.

Design tools enable robust, noise-resistant measurements.

Prototype validation confirms practical feasibility.

Abstract

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.