Yingsi Qin Aswin C. Sankaranarayanan Matthew O'Toole

Abstract

A lens brings a single plane into focus on a planar sensor; hence, parts of the scene that are outside this planar focus plane are resolved under defocus. Can we break this precept by enabling a “lens” that can change its depth of field arbitrarily? This work investigates the design and implementation of such a computational lens with spatially- selective focusing. Our design uses an optical arrangement of a Lohmann lens and a phase-only spatial light modulator to allow each pixel to focus at a different depth. We extend classical autofocusing techniques to the spatially-varying scenario where the depth map is iteratively estimated using contrast and disparity cues, enabling the camera to progressively shape its depth-of-field to the scene’s depth. By obtaining an all-in-focus image optically, our technique advances upon prior work in two key aspects: the ability to bring an entire scene in focus simultaneously, and the ability to maintain the highest possible spatial resolution.