title: Optimal pulse width modulation for sinusoidal fringe generation with projector defocusing.
abstract: Recently, a study showed that generating sinusoidal fringe patterns by properly defocusing binary ones can significantly simplify three-dimensional shape measurement system development and drastically improve its speed. However, when the fringe stripes are very wide, it is very difficult for this technique to achieve high-quality measurement. This Letter presents a method to improve this technique by selectively eliminating high-frequency harmonics induced by a squared binary pattern. As a result, better sinusoidal fringe patterns can be generated with a small degree of defocusing even for wide fringe stripes. Simulation and experiments will be presented to verify the performance of this proposed technique.
authors.affiliation: Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Wang
authors.forename: Song
authors.initials: S
authors.lastname: Zhang