Structured light measuring system calibration method based on sinusoidal grating

Abstract

The invention discloses a structured light measuring system calibration method based on sinusoidal grating. The method includes producing coding grating, setting up measuring system to capture calibrating board flat images, projecting coding grating, collecting, storing, confirming phase-unfolding initial points, solving wrapped phase and unfolding, restoring the calibrating board flat images of projector imaging planes, calibrating projectors according to the multi-group projector calibrating board flat images at different positions, calibrating cameras according to multiple camera calibrating board flat images at different positions, and acquiring rotation matrixes from projector coordinate systems to camera coordinate system according to calibrating results of the projectors and the cameras. The phase-unfolding initial point can be effectively confirmed by utilizing coding disc images, and image quality of image region is guaranteed to be high; and the designed phase-unfolding method has a noise-proof function, 'line-pulling' conditions in conventional phase-unfolding methods are overcome, and the designed structured light measuring system calibration method has the advantages of simple operation, strong robustness, high measurement accuracy and the like.

Description

technical field [0001] The invention relates to a calibration method of a structured light measurement system based on a sinusoidal grating, which belongs to the technical field of computer measurement. Background technique [0002] Structured light vision measurement is a new method for measuring the three-dimensional surface shape of objects. It has been widely used in industrial inspection, virtual reality, cultural relics protection and medical engineering in recent years due to its characteristics of non-contact, convenience, speed and high precision. Applications. As an active visual measurement method, structured light vision measurement uses a projector to project a pre-designed pattern onto the surface of the measured object to increase visual matching feature information, thereby solving the problem of stereo vision corresponding point matching, and then through triangulation The measurement realizes the acquisition of the depth information of the object surface. ...

AI Technical Summary

Problems solved by technology

[0004] For traditional system calibration methods, most of the phase unwrapping starts from the beginning of the image, but the quality of the edge of the image is often low and there are many noise points. Using such an area as the starting point of phase unwrapping will introduce errors prematurely. , resulting in phase unwrapping failure; in the phase unwrapping process, the traditional system calibration method uses ranks and columns to take packages point by point. The biggest shortcoming of this method is: in the phase unwrapping path, the error at the previous point will always continue The subsequent points, resulting in a "pull line" phenomenon

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