基于SIFT的小模数齿轮图像亚像素级配准研究

发布时间：2018-04-08 18:31

本文选题：视觉测量　切入点：小模数齿轮　出处：《仪器仪表学报》2017年09期

【摘要】：为解决小模数齿轮视觉测量中凸显的工业相机高空间分辨率与大视场相互制约的问题,对轮廓光条件下前景背景对比度过强、局部对比度不足,存在大面积同色区域的小模数齿轮图像亚像素级配准方法进行研究。针对传统基于特征点的图像配准流程在小模数齿轮图像配准中存在特征点数量稀少、正确匹配率过低的问题,介绍了适用于小模数齿轮图像的配准流程;引入直方图均衡化改善图像对比度,丰富灰度色调,增晰图像暗部特征以提升特征点数量和正确匹配率;为了克服传统匹配对提纯算法中阈值设置不准确、参数调整困难及模型不唯一的缺点,结合两倍中误差准则提出全局自适应参数匹配点对提纯方法,保证提纯结果唯一性的同时,其自适应调整判别阈值的方法可避免人为误差进而保证结果的重复性。实验结果表明,利用介绍的方法对图像进行预处理可大幅度提升特征点数量与正确匹配率,取提纯所得平移量的平均值作为配准结果,其正确度和精密度均优于传统算法,针对轮廓光条件下的小模数齿轮图像,配准精度优于0.083 pixel,对于小模数齿轮视觉测量具有实际应用价值。
[Abstract]:In order to solve the problem of high spatial resolution and large field of view of industrial camera which is highlighted in the visual measurement of small modulus gear, the contrast of foreground background is too strong and the local contrast is insufficient under the condition of contour light.The sub-pixel registration method for small modulus gear images with large area of homochromatic region is studied.Aiming at the problem that the number of feature points is scarce and the correct matching rate is too low in the traditional image registration process based on feature points, this paper introduces the registration process suitable for small modulus gear image.Histogram equalization is introduced to improve image contrast, rich grayscale hue, and blur image dark part feature to improve the number of feature points and correct matching rate, in order to overcome the inaccuracy of threshold setting in the traditional matching algorithm.It is difficult to adjust the parameters and the shortcomings of the model are not unique. Combined with the criterion of double median error, a global adaptive parameter matching point pair purification method is proposed to ensure the uniqueness of the purification results.This method can avoid the artificial error and ensure the repeatability of the result.The registration accuracy of small modulus gear image under contour light is better than that of 0.083 pixel, which has practical application value for vision measurement of small modulus gear.
【作者单位】：中国计量大学工业与商贸计量技术研究所;
【分类号】：TH132.41;TP391.41

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