Spacetime Stereo: A Unifying Framework for Depth from Triangulation
|Authors:||Davis, James, Nehab, Diego, Ramamoorthi, Ravi, Rusinkiewicz, Szymon|
Depth from triangulation has traditionally been investigated in a number of independent threads of research, with methods such as stereo, laser scanning, and coded structured light considered separately. In this paper, we propose a common framework called spacetime stereo that unifies and generalizes many of these previous methods. Viewing specific techniques as special cases of this general framework leads to insights regarding solutions to many of the traditional problems of individual techniques. Specifically, we discuss a number of possible applications such as improved recovery of static scenes under variable illumination, spacetime stereo for moving objects, structured light and laser scanning with multiple simultaneous stripes or patterns, and laser scanning of shiny objects. To suggest the practical utility of the framework, we use it to analyze two of these applications - recovery of static scenes under variable, but uncontrolled and unstructured illumination, and depth estimation in dynamic scenes. Based on our analysis, we show that methods derived from the spacetime stereo framework can be used to recover depth in situations in which existing methods perform poorly.