Optimized multilevel fringe patterns for real-time 3D shape measurement with defocused projector

Binary defocusing method is an efficient technique for 3D measurement. It allows real-time measurement by replacing conventional 8-bit fringe patterns with binary patterns. However, there is still room for improving the measurement accuracy of binary defocusing method. This paper presents a novel idea of projecting binary patterns through different color channels of a projector to increase the intensity levels of a fringe pattern without sacrificing the advantages of binary defocusing method. An algorithm is also proposed to optimize fringe patterns for the application. Both simulation and experimental results show that our method can improve the measurement accuracy substantially.