Local weights in phase unwrapping play an important role in guiding the flow of the phase integration. Unwrapping algorithms can proceed in a path-following or a non-path-following fashion. In path-following phase unwrapping algorithms, local weights guide the selection of unwrapping paths. In nonpath-following algorithms, the introduction of predetermined local weights is necessary to accommodate phase inconsistencies in practice. In current unwrapping algorithms, these local weights are extracted either from the quality information (correlation in interferometric synthetic aperture radar and modulation in phase shifting interferometry) or from the information contained in the wrapped phase difference alone. In other words, the crucial issue is how a phase unwrapping algorithm should select these location-associated weights in order to prevent the propagation of phase errors. This paper presents a quantitative scheme for selecting local weights for phase unwrapping opt the basis of both these types of information (the quality map and the wrapped phase). Real objects as well as synthetic ones have been investigated for various unwrapping methods in experiments. Integrated 3D free-form object models demonstrate the validity of the phasor-weighted phase unwrapping approach.

Automatic 3D object model construction is important in applications ranging from manufacturing to entertainment, since CAD models of existing objects may be either unavailable or unusable. We describe a prototype system for automatically registering and integrating multiple views of objects from range data. The results can then be used to construct geometric models of the objects. New techniques for handling key problems such as robust estimation of transformations relating multiple views and seamless integration of registered data to form an unbroken surface have been proposed and implemented in the system. Experimental results on real surface data acquired using a digital interferometric sensor as well as a laser range scanner demonstrate the good performance of our system.

Automatic 3D object model construction is important in applications ranging from manufacturing to entertainment industry, since CAD models of existing objects may be either unavailable or unusable. We describe a prototype system for automatically registering and integrating multiple views of objects using surface depth data to construct their geometric models. New techniques for handling key issues such as robust estimation of view transformations relating multiple views and seamless integration of registered data to form an unbroken surface have been proposed and implemented in our system. Our system has been tested on depth data that were obtained using digital interferometry techniques as well as a laser range scanner. Experimental results on real object surfaces demonstrate the good performance of our system.