Method for realizing fourier transform profilometry by using binary encoding strategy

Abstract

The invention discloses a method for realizing fourier transform profilometry by using a binary encoding strategy. A high-frequency sine structure light pattern is decomposed into a series of binary encoding patterns according to a bit plane; a binary pattern sequence is projected to a three-dimensional target by using a projection device; synchronous photographing is performed by using a photographing device; binaryzation treatment is performed on a photographed binary image; a high-frequency sine structure light image is synthesized according to correspondence of the bit plane and a gray level image; the synthesized sine structure light image is treated by using the fourier transform profilometry to obtain a truncated phase; the truncated phase is subjected to phase unwrapping to obtain an absolute phase; the three-dimensional coordinate of the surface of an object is calculated by using the absolute phase and system calibration parameters. The method can be used for measuring the three-dimensional surface shape of the object with diffuse reflection characteristic. According to the method, the problem of spectrum aliasing and background light interference existing in the conventional fourier transform profilometry can be effectively avoided; the method has higher measurement accuracy.

Description

technical field [0001] The invention relates to optical three-dimensional sensing technology, in particular to three-dimensional surface shape measurement of space objects based on Fourier transform profilometry. Background technique [0002] Fourier transform profilometry (Fourier Transform Profilometry, referred to as FTP) is a widely used non-contact optical three-dimensional measurement technology, the paper "Su, X., & Chen, W. (2001). Fourier transform profilometry: a review . Optics and lasers in Engineering , 35 (5), 263-284” introduced the principle of Fourier transform profilometry in detail. Because Fourier transform profilometry generally only needs one frame of high-frequency structured light pattern, its remarkable advantage is that it can perform real-time monitoring of moving objects. Three-dimensional measurement. The core step of Fourier transform profilometry is to use a band-pass filter to filter out the DC component and higher harmonics in the frequency...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to solve the problem of spectrum aliasing caused by the traditional Fourier transform profilometry due to the spatial variation of background brightness and object reflectivity, random noise, and the nonlinearity of the camera-projector system, and propose a three-dimensional transmission method. In sensing technology, Fourier transform profilometry using binary coding strategy, this method can solve the problem of spectral aliasing, and is not affected by background light, and has high measurement accuracy on the basis of ensuring fast measurement

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