[摘要]：Phase measuring profilometry based on structured illumination with a digital projector has great flexibility. However, the phase error introduced by the gamma nonlinearity of the projector and the presence of Speckle noise inevitably decreases the accuracy and resolution of the measurement. This paper presents a new phase error correction algorithm by which the odd-step fringe projection is done twice with an initial phase shift of pi between, and the two captured deformed fringe images are then digitally subtracted. The speckle noise is further suppressed by applying a sine-cosine median filter. Both theoretical analysis and experimental results showed that this algorithm is effective and fast. (c) 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3407430]
