光学学报, 2018, 38 (8): 0812002, 网络出版: 2018-09-06
基于灰度梯度正则化去噪的改进数字图像相关法 下载: 1064次
Improved Digital Image Correlation Method Based on Gray Gradient Denoised by Regularization Method
测量 数字图像相关 Tikhonov正则化 灰度梯度 噪声 measurement digital image correlation Tikhonov regularization gray gradient noise
摘要
为了提高数字图像相关法的抗噪声能力,分析了灰度梯度计算误差对数字图像相关法测量精度的影响,提出采用Tikhonov正则化方法计算图像灰度梯度,进而通过反向组合高斯-牛顿(IC-GN)法计算图像的亚像素位移;基于数值仿真散斑图研究灰度梯度的相对计算误差,并分析采用Tikhonov正则化方法计算图像灰度梯度后,改进数字图像相关法的测量精度,结合实验验证所提方法在实际噪声环境中的抗噪声能力。结果表明:灰度梯度对数字图像相关法测量精度有较大影响,而采用Tikhonov正则化方法后,可以有效提高数字图像相关法的测量精度与抗噪声能力。
Abstract
To improve the anti-noise ability of the digital image correlation method, we analyze the influence of gray gradient calculation error on the measurement accuracy of the digital image correlation method. An improved algorithm is proposed to calculate the gray gradient of the image by the Tikhonov regularization method and the sub-pixel displacement of the image by the inverse compositional Gauss-Newton (IC-GN) method. On the basis of the numerical simulation of the speckle pattern, the relative calculation error of the gray gradient is studied, and the measurement accuracy of the digital image correlation method is analyzed after calculating the gray gradient of the image by the Tikhonov regularization method. The proposed method is verified by experiments in the noise environment. The results show that the gray gradient has great influence on the measurement accuracy of the digital image correlation method. Meanwhile, the measurement accuracy and the anti-noise ability of the digital image correlation method can be effectively improved by the Tikhonov regularization method.
郑成林, 何顶顶, 费庆国. 基于灰度梯度正则化去噪的改进数字图像相关法[J]. 光学学报, 2018, 38(8): 0812002. Chenglin Zheng, Dingding He, Qingguo Fei. Improved Digital Image Correlation Method Based on Gray Gradient Denoised by Regularization Method[J]. Acta Optica Sinica, 2018, 38(8): 0812002.