Single-shot acquisition of optical direct and global components using single coded pattern projection

Abstract

We present a single-shot approach for separating optical direct and global components from an object. The former component is caused by direct illumination that travels from a light source to a point on the object and goes back to a camera directly. The latter one is caused by indirect illumination that travels from the light source to a point on the object through other points and goes back to the camera, such as multi-path reflection, diffusion, and scattering, or from another unintended light source, such as ambient illumination. In this method, the direct component is modulated by a single coded pattern from a projector. The modulated direct and un-modulated global components are integrated on an image sensor, which captures a single image. These two components are separated from the single captured image with a numerical algorithm employing a sparsity constraint. Ambient light separation and descattering based on the proposed scheme are experimentally demonstrated.