Digital Phase Shifting 3-D Measurement System And Phase Error Compensation Method

Structured light 3-D measurement based on digital phase shifting has been tremendously advanced in recent years. A lot of different measure systems have been developed based on various principles. However, high accuracy phase error compensation methods are still to be advanced. Digital phase shifting 3-D measurement is the topic of this dissertation, phase measuring algorithms, digital projection characteristics and phase error compensation methods are mainly discussed.Phase measuring algorithms include phase calculation and phase unwrapping which is the foundation of digital phase shifting 3-D measurement. Theoretical analysis and experiment are employed to evaluate algorithms.Digital projection is also discussed in this dissertation. The characteristics of projected signal are analyzed and pixelate and Gamma distortion is also investigated which would affect the projected phase shifting fringes.Pixelate and Gamma distortion contributes most to phase error in digital phase shifting 3-D measurement. Both of theoretical analysis and experiment are employed to investigate the characteristic of phase error. Non-uniform Gamma distribution of digital projector is analyzed and a generic phase error compensation method by phase error Look-Up-Table is proposed and verified by experiment.