A computer-assisted method for localizing a rack, including sensing an image
of
the rack, detecting line segments in the sensed image, recognizing a candidate
arrangement of line segments in the sensed image indicative of a predetermined
feature of the rack, generating a matrix of correspondence between the candidate
arrangement of line segments and an expected position and orientation of the predetermined
feature of the rack, and estimating a position and orientation of the rack based
on the matrix of correspondence.