On the Relationship Between Dual Photography and Classical Ghost Imaging

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.