Spacetime Stereo: A Unifying Framework for Depth from Triangulation

Abstract:

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.