Wide Area Camera Calibration Using Virtual Calibration



This paper introduces a method to calibrate a wide area
system of unsynchronized cameras with respect to a single
global coordinate system. The method is simple and does
not require the physical construction of a large
calibration object. The user need only wave an
identifiable point in front of all cameras. The method
generates a rough estimate of camera pose by first
performing pair-wise structure-from-motion on observed
points, and then combining the pair-wise registrations
into a single coordinate frame. Using the initial camera
pose, the moving point can be tracked in world space. The
path of the point defines a “virtual calibration object”
which can be used to improve the initial estimates of
camera pose. Iterating the above process yields a more
precise estimate of both camera pose and the point path.
Experimental results show that it performs as well as
calibration from a physical target, in cases where all
cameras share some common working volume. We then
demonstrate its effectiveness in wide area settings by
calibrating a system of cameras in a configuration where
traditional methods cannot be applied directly.