High-Speed Phase Structured Light Integrated Architecture on FPGA

Phase-shifting fringe projection profilometry (FPP) in 3-D structured light measurement is widely applied in high-accuracy 3-D shape measurement scenarios. However, motion objects or other dynamic scenarios make the traditional phase-shifting FPP hard to deal with due to its sizable central-processing-unit-based execution time. Therefore, an embedded high-speed and high-accuracy phase-shifting FPP system is designed and implemented on field-programmable gate arrays. The system implements a three-frequency four-step phase-shifting hardware algorithm with register-transfer-level caching, multiframe image ping-pong buffering, and data handling. The system exhibits fully parallel and pipeline processing while behaving with lower resource and power consumption. Measurement experiments indicate that the proposed method can reach high-accuracy real-time 3-D shape measurement with a 3-D decoding speed of 40.15 frames/s when the clock frequency is 200 MHz and the image size is 2432 × 2048.