Reconstructing the Surface of Inhomogeneous Transparent Scenes by Scatter-Trace Photography

Abstract

We present a new method for reconstructing the exterior surface of a complex transparent scene with inhomogeneous interior (e.g., multiple interfaces, reflective or painted interiors, etc). Our approach involves capturing images of the scene from one or more viewpoints while moving a proximal light source to a 2D or 3D set of positions. This gives a 2D (or 3D) dataset per pixel, called the scatter trace. The key idea of our approach is that even though light transport within a transparent scene's interior can be exceedingly complex, the scatter trace of each pixel has a highlyconstrained geometry that (1) reveals the contribution of direct surface reflection, and (2) leads to a simple "scattertrace stereo" algorithm for computing the local geometry of the exterior surface (depth and surface normals). We present 3D reconstruction results for a variety of scenes that exhibit complex light transport phenomena.

Refractive shape from light field distortion

“…Range scanning can be used for the acquisition of refractive solids, if they are immersed in a fluorescent liquid [13]. Morris and Kutulakos show that the surface of complex refractive objects can be reconstructed from multiple photographs with changing illumination [22]. Furthermore, specular objects can be acquired using shape from distortion [31,6].…”

“…A popular alternative is the analysis of refractive distortions of diffuse background or illumination pattern [23,28,5,1,17,21,31,6,22]. Such approaches typically require multiple cameras, or multiple images from the same camera taken with varying illumination or background patterns.…”

Looking around the corner using transient imaging

“…Accurate measurement of physical scene properties is called inverse-rendering [5]. Complex models have been developed for reconstructing specular [6], transparent [7], Lambertian [8] scenes and joint lighting and reflectance [9]. Recent work in image-based modeling and computational photography has also shown several methods for capturing steady-state light transport [10].…”

Mesostructure from specularity using gradient illumination

“…Recently screen-camera('s) setups have also been introduced as a device for normal map acquisition [Morris and Kutulakos 2007;Francken et al 2008b;Francken et al 2008a;from Specularity Consistency 2008], and our work falls into this category. However, in this paper we will considerably reduce the necessary number of image captures by carefully chosing the light patterns.…”