一种2D-VMD与NLM结合的芯片图像去噪算法研究

Chip Image Denoising Algorithm Based on Bi-dimensional Variational Mode and Non-local Mean Filtering

为了提高智能电表芯片图像的字符识别精度,需要消除芯片图像中的噪声,以减小干扰;文章提出了一种基于二维变分模态分解算法(2D-VMD)与非局部均值(NLM)滤波的芯片图像去噪算法;首先利用2D-VMD将含有噪声信号的芯片图像分解为K个模态分量;然后根据提出的结构相似(SSIM)阈值设置方法确定噪声分量并将其去除,使用剩余的有效分量重构图像;最后通过非局部均值滤波算法对重构后的图像进行处理,进一步滤除残余噪声,达到二次去噪的效果;实验结果表明,相比传统的图像去噪算法,提出的算法能在较好保留原始芯片图像的字符信息的基础上,去除不相关的噪声干扰,使去噪后的芯片图像的均方误差值变小,峰值信噪比增大,提高芯片图像质量。

To retain the character information of the smart meter chip image and remove noise interference,a chip image denoising algorithm combining two-dimensional variational modal decomposition algorithm and non-local mean filtering was proposed.On the basis of the center frequency observation method,2D-VMD was used to decompose the noisy chip image into K modal components,and the noise modal components were removed according to the structural similarity measure(SSIM)threshold method,the NLM algorithm used to the effective component in the 2D-VMD algorithm and through the way of the secondary image denoising to achieve the effect of precise denoising.Experimental results show that the mean square error value and the peak signal-to-noise ratio of proposed algorithm are superior to the traditional filtering algorithms.