3D reconstruction from focus for lensless imaging

Abstract

The lensless camera is an ultra-thin imaging system that utilizes encoding elements instead of lenses to perceive the light field and reconstruct it through computational methods. Early studies have demonstrated that lensless cameras can encode 3D scenes at various depths in caustic patterns with varying sizes, known as point spread functions (PSFs). By deconvolving measurements with these PSFs, the reconstruction exhibits distinct focusing effects: objects in the focal plane appear sharp, while objects in other planes become blurred. Building upon this feature, we propose a feedforward network based on depth from focus to generate the depth map and the all-in-focus image by reconstructing the focal stack and deriving the probability of pixel clarity. Using our optimization framework, we present superior and more stable depth estimation than previous methods in both simulated data and real measurements captured by our lensless camera.