一种基于图像灰度变化的水平位移监测方法

A Horizontal Displacement Monitoring Method Based on Image Gray Change

以利用数字图像相关算法准确跟踪被测物上目标点的运动为核心,首先提出了定量、可靠地评价变形前后图像子区相似程度的方法;然后利用Newton-Raphson模型提高了亚像素位移监测精度;最后使用图像子区平均灰度梯度来评价图像质量,获得水平位移监测结果。选取模拟基坑进行区域位移监测试验,并与国内流行的水平位移监测方法进行对比分析。

In this paper,the motion of target points on the measured object is accurately tracked by digital image correlation algorithm.Firstly,a method to quantitatively and reliably evaluate the similarity of image sub regions before and after deformation is proposed;Then,the accuracy of sub-pixel displacement monitoring is improved by using Newton-Raphson model;Finally,the average gray gradient of image sub area is used to evaluate the image quality and obtain the horizontal displacement monitoring results.The simulated foundation pit is selected for regional displacement monitoring test,and compared with the popular horizontal displacement monitoring method in China.