Pose determination of a three-dimensional object using triangle pairs

A procedure is presented to estimate the unconstrained three-dimensional location and orientation of an object with a known shape when it is visible in a single image. Using a generalized Hough transform, all six parameters of the object position are estimated from the distribution of values determined by matching triples of points on the object to possibly corresponding triples in the image. Most likely candidates for location are found, and then the remaining rotational parameters are evaluated. Two solutions are generally admitted to the distribution by every match of triangles. The number of possible matches is reduced by checking a simple geometric relation among triples. Even with partial occlusion, experiments indicate that the procedure is very reliably accurate, although optimization can further improve estimates of the parameters