Analysis of uncertainty bounds due to quantization for three-dimensional position estimation using multiple cameras

An important source of error when estimating the 3-D position of a point from two (stereo), three (trinocular), or more cameras is that of quantization error on the image planes. In this paper, we are concerned with bounding the quantization errors when using multiple cameras defined in terms of uncertainty regions in 3-D. We use a geometric error analysis method that models the quantization error as projected pyramids and the uncertainty region as an ellipsoid around the polyhedron intersection of the pyramids. We present a computational technique for determining the uncertainty ellipsoid for an arbitrary number of cameras. A numerical measure of uncertainty bound such as the volume of the ellipsoid can then be computed for aiding camera placement, trajectory planning, and various other multiple camera applications.