一种改进的非局部均值图像去噪算法

传统非局部均值滤波算法中使用指数型加权核函数，容易导致图像细节因过度平滑而变得模糊。为此，在指数型加权核函数的基础上，采用余弦系数加权的高斯核函数，设计一种改进的非局部均值图像去噪算法，并将其应用于加权系数计算中。实验结果表明，该算法的去噪性能优于传统算法，且能更好地保留原图像的细节信息，峰值信噪比最大可以提升1.6 dB。

Improved Non-local Means Algorithm for Image Denoising

Aiming at the problem of the over-smoothness and blurs the details, which are caused by exponential kernel function used in original non-local means algorithm, this paper proposes a cosine Ganssian kernel function based on exponential kernel function and combined with a cosine coefficient and Gaussian kernel. It is used in the weight-computing of the improved algorithm. Experimental results show the algorithm has a superior denoising performance than the original one, especially with detail information in the image, and PSNR can be improved by 1.6 dB at most.