3D shape measurement accelerated by GPU

Driven by the increasing demands of the general purpose in computation and image display, Graphics Processing Unit(GPU) has been developed and used in many fields, such as medical field, scientific calculations, image processing etc.. But, its application in 3D shape measurement is still a beginning. In this paper, two 3D shape measurement systems based on Fourier Transform Profilometry(FTP) and tri-frequency heterodyne method were implemented with Compute Unified Device Architecture(CUDA) technology to speed up their 3D shape construction of a measured static or dynamic object. In the first 3D shape measuring system based on tri-frequency heterodyne method, a high-speed digital projection module and a synchronously triggered camera were used to record 12 deformed fringe images on the surface of a small object. The experimental result demonstrates that the efficiency of the unwrapping phase calculation by GPU is improved 2 089 times than that of CPU for doing same task on 12 images with 1 360 pixel1 024 pixel each. In the second system based on FTP, only one deformed fringe image was recorded by a camera, then transferred into GPU and processed by the programmed CUDA algorithm to restore the corresponding 3D shape. Compared with the traditional processing method by CPU, the time consumption of FTP method completed by GPU is shortened 27 times for a 1 024 pixel1 280 pixel image.