A 3D measurement method based on random two-frame phase-shifted fringe patterns

Abstract

The invention relates to a three-dimensional measurement method based on random two-frame phase-shifted fringe patterns, comprising: sequentially projecting a first fringe pattern and a second fringe pattern to an object to be measured to obtain a first deformed fringe pattern and a second deformed fringe pattern; Background filtering and modulation magnitude correction are performed on the first deformed fringe image and the second deformed fringe image to obtain the first correction result and the second correction result; the first correction result and the second correction result are obtained by using the Lissajous ellipse fitting method The correction result is processed to obtain the phase information of the object to be measured; according to the phase information, the three-dimensional shape information of the object to be measured is obtained. The method of the present invention extracts the phase information of the object using the Lissajous ellipse fitting technology and applies it to the fringe projection system. Only two frames of fringe images with uneven background intensity and modulation degree are used to reconstruct the three-dimensional shape of the object. The calculation is more convenient and the reconstruction The 3D topography has high robustness and accuracy.

Description

technical field [0001] The invention belongs to the technical field of three-dimensional measurement of objects based on fringe projection, and in particular relates to a three-dimensional measurement method based on random two-frame phase-shifted fringe images. Background technique [0002] In the field of 3D object surface measurement, 3D object measurement technology based on fringe projection technology has been widely used in various fields, such as industrial detection, face detection, medical plastic surgery, etc., due to its low cost, high precision, high reliability and Non-contact has become one of the most commercialized and efficient methods in 3D object measurement technology. This technology uses a projector to project fringes onto the surface of the object to be measured. Changes in the shape of the object to be measured cause the fringe to deform. The fringe deformation is analyzed and the phase information of the deformed fringe pattern is extracted to obtai...

AI Technical Summary

Problems solved by technology

However, it is difficult to achieve high-speed three-dimensional measurement due to the need for multi-frame fringe patterns to extract the phase of the object, and when measuring moving objects, the phase shift between the captured moving object fringe patterns is not uniform, which will lead to phase measurement errors. In addition, when the object is moving, the time interval between frames cannot be ignored, so it will not be possible to capture the motion information of the object between frames, so real-time three-dimensional measurement cannot be realized

[0004] Single-frame methods, such as Fourier profilometry, only require one frame of fringe images to extract the phase information of the object. This method has advantages in fast measurement, but it is usually very sensitive to noise and surface texture changes and due to spectral loss. The reconstruction accuracy of this method is not high

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