Despite dramatic increases in the performance of graphics hardware, the use of 3D graphics by most users remains limited because of the difficulty of creating or obtaining 3D content. The widespread availability of inexpensive, easy to use 3D scanning systems will help bridge this "content gap", with impacts in fields ranging from art education and cultural heritage preservation to construction and law enforcement. The aim of this research is to develop a theoretical understanding of triangulation-based 3D scanning systems and to design new 3D scanners that are flexible, robust, inexpensive, and easy to use. As a specific example, the project involves bringing 3D scanning into elementary school classrooms by developing a scanning system that can be built out of Lego cameras and building blocks, set up by teachers, and operated by fourth graders. The goal is to encourage early interest in science, technology, and arts by letting students create their own computer-animated movies.
The research builds upon a framework of "space-time stereo" to generalize many currently used scanner designs, such as stereo and laser stripe scanning. An analysis of existing and novel scanners relates the processing performed by the systems, consisting of correspondence across spatial, temporal, or space-time windows, to properties of the object being scanned (such as depth variation, presence or absence of color texture, and speed of motion). Based on this analysis, new 3D scanner designs are developed that eliminate the need for expensive optics and motors while being more adaptable to a wide range of scanning scenarios. Several specific applications are implemented, including an inexpensive, high-resolution desktop scanner for small objects, scanners for building interiors that flexibly incorporate multiple cameras and projectors, and an omni directional scanner that captures an entire room at once. Efficient and stable alignment algorithms combine the multiple scans obtained by each scanner into complete 3D models.
