Computational imaging, relighting and depth sensing using flexible thin-film sensors.

Abstract

We wrap a thin-film luminescent concentrator (LC) - a flexible and transparent plastic foil doped with fluorescent dye particles - around an object to obtain images of the object under varying synthetic lighting conditions and without lenses. These images can then be used for computational relighting and depth reconstruction. An LC is an efficient two-dimensional light guide that allows photons to be collected over a wide solid angle, and through multiple overlapping integration areas simultaneously. We show that conventional photodetectors achieve a higher signal-to-noise ratio when equipped with an LC than in direct measurements. Efficient light guidance in combination with computational imaging approaches, such as presented in this article, can lead to novel optical sensors that collect light in a structured way and within a wide solid angle rather than unstructured through narrow apertures. This enables flexible, scalable, transparent, and lens-less thin-film image and depth sensors.