A high-precision three-dimensional reconstruction method for step edges

Abstract

The present application relates to a kind of step edge high-precision three-dimensional reconstruction method, using the parallel single-pixel imaging principle based on projection reconstruction, in combination with edge detection algorithm and adaptive bidirectional projection strategy solve the light ray aliasing problem of step edge, to realize the high-precision acquisition of step edge three-dimensional stereo matching point.First, the sequence of phase-shifted fringe pattern of bidirectional periodic continuation is generated, is projected to measurement scene by projector in turn, and the coded image of scene is obtained by camera synchronous acquisition.Then, the lower frequency image in fine positioning fringe image is extracted to calculate absolute phase map, carries out edge extraction, generates edge mask image.Secondly, the one-dimensional projection function calculation of bidirectional is carried out to the edge pixel in mask image, further calculate the intersection of projection line to obtain multiple intersection points of bidirectional projection line as candidate matching point, and two direct matching points from upper and lower surfaces of step edge are screened out by epipolar distance constraint.Finally, using calibration parameter and matching point, three-dimensional reconstruction point cloud of step edge is obtained by solving stereo matching algorithm.The application effectively solves the light ray aliasing problem of step edge caused by camera visual angle obstruction in triangulation camera-projector system, reconstructs the upper and lower surfaces of step edge completely, and improves the three-dimensional measurement precision of step edge.Based on the optimized bidirectional projection reconstruction parallel single-pixel imaging, while ensuring the measurement accuracy, the measurement efficiency is improved, which is conducive to the application and popularization of the method in actual industrial measurement field.

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