Rapid three-dimensional measurement method based on color grating projection

Abstract

The invention relates to a rapid three-dimensional measurement method based on colorful grating projection in a three-dimensional scanning system. The method comprises the following steps: selecting four pure colors of green, yellow, cyan and white so as to carry out color strip encoding, wherein the G component values of the four pure colors are 255, and the R component values and the B component values of the four pure colors are respectively 0 or 255; after finishing color encoding, carrying out sinusoidal modulation on the G component of strip color to finally obtain a projective grating; on one hand, resolving G component information to obtain a folding phase value by a method based on Fourier transform, on the other hand, carrying out binaryzation on the R component and B component of an image by an iteration threshold method in the color image segmentation link, and automatically assigning 255 to the G component; and segmenting an image decipher to obtain phase period information so as to unfold the phase. By utilizing the method, inconvenience for cutting brought by periodic occurrence of light and shade strip-shaped areas in the image caused by G component sinusoidal modulation can be well avoided, and a train of thought for realizing three-dimensional dynamic measurement can be provided on the premise of not influencing the measurement accuracy.

Description

technical field [0001] The invention belongs to the technical field of three-dimensional information reconstruction, and uses fringe projection profilometry for three-dimensional measurement of objects based on color grating projection and Fourier transform method. The whole system involves color projection grating design, image segmentation, phase acquisition and other parts. Background technique [0002] 3D contour detection and reconstruction technology is a branch of computer image processing technology, and a research direction combining computer vision and computer graphics and image processing. It is widely used in the fields of production automation, robot vision, CAD, virtual reality and medical image diagnosis. All have broad application prospects. [0003] Because the grating projection method has the characteristics of completely non-contact detection process, high spatial resolution of data, one-time instant projection to directly realize the shape detection of...

AI Technical Summary

Problems solved by technology

In addition, in terms of phase unwrapping technology, in addition to the traditional gray-scale code method using seven progressively dichotomized black and white fringe images to determine the periodic information of the phase, there are also methods based on edge jump detection and quality map guidance. Generally, the grayscale information of the image is used, and the algorithm implementation is more complicated; and the phase period is determined by using the color information carried by the color code, which not only reduces the number of collected images, but also reduces the complexity of the algorithm. On the premise of not affecting the accuracy, It can improve the dynamic performance of measurement very well, so the application of three-dimensional measurement method based on color-coded raster projection is becoming more and more extensive

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