On the Relationship Between Dual Photography and Classical Ghost Imaging

TL;DR

This paper reveals that classical ghost imaging is fundamentally a form of dual photography, linking the two techniques through light transport measurement and reciprocity, and suggesting ways to enhance ghost imaging using dual photography principles.

Contribution

The paper establishes a mathematical equivalence between ghost imaging and dual photography, providing a new classical optics explanation and potential improvements for ghost imaging systems.

Findings

Ghost imaging is a realization of dual photography.

Cross-correlation methods in ghost imaging are equivalent to light transport measurement.

Classical optics and reciprocity explain ghost imaging phenomena.

Abstract

Classical ghost imaging has received considerable attention in recent years because of its remarkable ability to image a scene without direct observation by a light-detecting imaging device. In this article, we show that this imaging process is actually a realization of a paradigm known as dual photography, which has been shown to produce full-color dual (ghost) images of 3D objects with complex materials without using a traditional imaging device. Specifically, we demonstrate mathematically that the cross-correlation based methods used to recover ghost images are equivalent to the light transport measurement process of dual photography. Because of this, we are able to provide a new explanation for ghost imaging using only classical optics by leveraging the principle of reciprocity in classical electromagnetics. This observation also shows how to leverage previous work on light transport acquisition and dual photography to improve ghost imaging systems in the future.