Positioning method for sub-pixel at center of line laser in three-dimensional laser scanning system

Abstract

The invention discloses a positioning method for a sub-pixel at center of line laser in a three-dimensional laser scanning system. The method comprises the steps of firstly acquiring original image information in laser scanning from a camera, performing preprocessing on an original image, eliminating noises in the image; performing threshold segmentation on the image after noise elimination, and performing crude extraction on the line laser; eliminating a burr phenomenon in the line laser after crude extraction, and further reducing width of the line width; obtaining a sub-pixel grade coordinate of the line laser center by means of an improved gravity center method, and correcting pseudo-object pixels in the sub-pixel grade coordinate by means of Hough transform. According to the positioning method, the improved gravity center method is combined with the Hough transform, a requirement for real-time and accurate acquisition of the sub-pixel coordinate of the line laser center by the three-dimensional laser scanning system can be satisfied, and accurate positioning for sub-pixel at the center of the line laser is realized.

Description

technical field [0001] The invention relates to a method for sub-pixel positioning of a line laser center in a three-dimensional laser scanning system. Background technique [0002] With the continuous development of machine vision technology, 3D laser scanning technology has gradually become the core force in this field. With the advantages of real-time acquisition of 3D data information on the surface of the object to be measured, high scanning accuracy and non-contact characteristics, 3D laser scanning has become one of the hotspots of new technology research. [0003] The three-dimensional laser scanning system is generally composed of a line laser, a camera, a stepping motor, a rotating platform, etc. The line laser is used to emit a line laser light band, and the camera is used to capture the image containing the line laser on the surface of the measured object in real time. The motor and the rotating platform are used to obtain scanning information from multiple angl...

AI Technical Summary

Problems solved by technology

The curve fitting algorithm has high extraction accuracy and can reach sub-pixel accuracy, but the amount of data processed in the calculation process is relatively large

[0006] Various algorithms have their advantages and disadvantages according to their different principles. The advantages of the extreme value method, the threshold method, and the gray center of gravity method are that the algorithm is simple, the speed is fast, and it can realize real-time scanning, but it is seriously affected by noise.

Curve fitting method and Hessian matrix method have high extraction accuracy, can reach the sub-pixel level, are less susceptible to noise interference and have good robustness, but the algorithm complexity is high, the detection speed is slow, and it cannot meet the real-time requirements

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