Using plane + parallax for calibrating dense camera arrays

A light field consists of images of a scene taken from different viewpoints. Light fields are used in computer graphics for image-based rendering and synthetic aperture photography, and in vision for recovering shape. In this paper, we describe a simple procedure to calibrate camera arrays used to capture light fields using a plane + parallax framework. Specifically, for the case when the cameras lie on a plane, we show (i) how to estimate camera positions up to an affine ambiguity, and (ii) how to reproject light field images onto a family of planes using only knowledge of planar parallax for one point in the scene. While planar parallax does not completely describe the geometry of the light field, it is adequate for the first two applications which, it turns out, do not depend on having a metric calibration of the light field. Experiments on acquired light fields indicate that our method yields better results than full metric calibration.

1. Introduction

The 4D light field is commonly defined as the radiance along all rays that intersect a scene of interest. In practice, light fields are acquired by obtaining images of a scene with a camera from several different viewpoints (which often lie on a plane). These images constitute a dense sampling of rays in the light field. The number of images is typically large, ranging from hundreds to tens of thousands. Lights fields are useful for several applications in computer graphics and vision: