Fundamentals of Wearable Computers and Augmented Reality, 2nd Edition

188 Fundamentals of Wearable Computers and Augmented Reality

The region of convergence of the tracker determines the amount of error in the

pose prior that the system can tolerate. The continuous pose tracker uses a patch

search method to nd a point given a pose prior. This search occurs over a xed

region around the estimated point projection location, and is run over an image pyra-

mid to expand the search region. This establishes a maximum pixel error in the

projected point location that will still lead to tracker convergence.

We use a simplied analysis here by considering movement in one dimension, to

produce an estimate of the tracker convergence region.

Assuming rotation around the Y-axis (vertical axis), a rotational error of q

err

degree ...