A global registration system and method identifies bronchoscope position without the need for significant bronchoscope maneuvers, technician intervention, or electromagnetic sensors. Virtual bronchoscopy (VB) renderings of a 3D airway tree are obtained including VB views of branch positions within the airway tree. At least one real bronchoscopic (RB) video frame is received from a bronchoscope inserted into the airway tree. An algorithm according to the invention is executed on a computer to identify the several most likely branch positions having a VB view closest to the received RB view, and the 3D position of the bronchoscope within the airway tree is determined in accordance with the branch position identified in the VB view. The preferred embodiment involves a fast local registration search over all the branches in a global airway-bifurcation search space, with the weighted normalized sum of squares distance metric used for finding the best match.
