A fast and high-accuracy method for sub-pixel extraction of light strip center

Abstract

The invention discloses a method for fast and high-precision extraction of light bar center sub-pixel, belongs to the technical field of computer vision measurement, and relates to the method for fastand high-precision extraction of the light bar center sub-pixel.Based on a local quadratic curve approximation, the method can quickly solve the normal direction of the light bar and calculate a light bar sub-pixel center by a second order Tailor expansion.Firstly, the center position of the initial light bar is extracted by using the threshold light bar center with fast operating rate, the normal direction of the light bar of an initial center point position is quickly solved by the local quadratic curve approximation method, and a light bar center of sub-pixel accuracy is solved after normalization processing by using the second order Tailor expansion of an image function on the initial center point position. The method simplifies the solution of the normal direction of the light bar, and extracts the center coordinates of the sub-pixel of the light bar with high precision in the normal direction so as to achieve high precision and high efficiency dual requirements. In view of the complex illumination environment and measurement object in the scene, the adaptability and robustness are stronger, and the overall performance is better.

Description

technical field [0001] The invention belongs to the technical field of computer vision measurement, and relates to a fast and high-precision method for extracting sub-pixels in the center of a light strip. Background technique [0002] In order to restore the three-dimensional information of the surface of the workpiece to be measured, the extraction of high-precision surface feature information is particularly important. In the measurement scheme using binocular vision combined with auxiliary line laser scanning, the line laser stripes are projected on the surface of the measured object, and the center of the modulated laser stripes reflects the spatial position information of the measured object. Therefore, accurate light strip center extraction is the key to realize high-precision measurement of three-dimensional shape and surface. [0003] At present, the commonly used light bar center extraction methods mainly include extreme value method, threshold method, gray scale ...

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is that the lighting environment of the large-scale curved surface measurement site is complex, the light strip image taken has local high reflection and overall uneven illumination, and the light strip in the local area is overexposed and the light strip in the local area is too dark. In order to solve the problem of the integrity and accuracy of light strip extraction, a fast and high-precision method for extracting sub-pixels in the center of light strips was invented.

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