Fitts correlation tracker fidelity in presence of target translation, rotation, and size change

摘要

The Fitts correlation algorithm is known to be optimal in measuring small image translations. As the position measurement portion of an image-based tracker, it yields excellent track fidelity over a sequence of images in which the tracked target exhibits small shifts from the predicted position. Real-world experience, however, informs us that the tracked target rarely confines itself to small-scale translational motion in the image plane, and sometimes changes size during the track period. When does the steady-state Fitts correlation need a boost from auxiliary algorithms to maintain target lock? We describe the envelope within which the Fitts correlation tracker can be expected to report target position accurately. Tolerances for target translation, in-plane rotation, and size change are parameterized by the correlation length of the tracked target. A successful image-based tracker using Fitts correlation for position measurement will require additional logic or modifications to the image-processing algorithm to enable it to operate outside the bounds described.