3D Surface Shape Measurement Method Based on GPU

Abstract

The invention discloses a method for GPU-based (Graphics Processing Unit) object three-dimensional shape measurement, and belongs to the technical field of object three-dimensional measurement. The method particularly comprises the following steps: projecting structure grating to the surface of an object to be measured by a projector; shooting the surface of the object to be measured by two cameras simultaneously to obtain two groups of image sequences; storing the two groups of image sequences into computer memory; completing distortion correction, phase demodulation, corresponding points matching and three-dimensional reconstruction for the image by a GPU in parallel; transmitting the object three-dimensional coordinate obtained through three-dimensional reconstruction to the computer memory by the GPU; repeating the above steps until the measurement is complete, and releasing the GPU and the storing space. The method adopts multi-core GPU to realize the parallel calculation at thread level, greatly increases data processing speed, and can satisfy the real-time requirement for three-dimensional measurement of a dynamic object.

Description

technical field [0001] The invention relates to the technical field of three-dimensional measurement of objects, in particular to a GPU (Graphic Processing Unit, Graphic Processing Unit)-based method for measuring three-dimensional surface shapes of objects, and is especially suitable for three-dimensional surface measurement of dynamic objects. Background technique [0002] Optical three-dimensional measurement is a method and technology for non-contact acquisition of the external shape of the measured object by using appropriate optical and electronic instruments. In production, the use of three-dimensional surface shape measurement technology can not only make full use of existing design and manufacturing achievements, improve design speed and shorten development cycle; it can also accurately detect product accuracy and improve product quality. In today's 3D measurement field, the structured light 3D dynamic measurement technology can actively select the measurement metho...

AI Technical Summary

Problems solved by technology

Although Song Zhang from Iowa State University in the United States and Weise from the Swiss Federal Institute of Technology used the parallel computing capability of the GPU in the implementation of the algorithm to improve the measurement efficiency, this method can only optimize algorithms similar to 3D graphics processing (specifically including : phase principal value calculation and three-dimensional reconstruction), for complex algorithms such as phase unwrapping, it is still only possible to run pixel-by-pixel serial calculations on the CPU

This traditional CPU+GPU hybrid architecture mode requires multiple accesses to the Global memory and multiple data transfers between the GPU and the CPU. Limited by memory and bus bandwidth, the improvement in operating efficiency is still very limited.

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