Predictive segmentation method for 3D inspection accuracy and robustness improvement

Accuracy and robustness of 3D inspection methods, which are based on structural lightening, strongly depend on surface reflectance and its geometry. If the intensity of light profile undergoes disturbances or the image is interfered with reflection artefacts, then the algorithms for height determination fail. The paper presents a method for predictive light profile line segmentation which employs information from 3D model of inspected object. Besides calculation of profile position, based on confidence intervals, the advantage of surface normal pitch and surface scattering are utilized. The necessary information is calculated based on STL object model and surface description extension. The developed algorithm includes error model of camera and laser optics, what corrects distortion and vignetting. The developed solution increases accuracy and robustness of machine vision quality inspection systems especially based on laser triangulation.

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