基于旋转块的BM3D图像去噪改进算法

针对经典BM3D去噪算法中存在的相似块匹配误差较大及对图像细节保护不足的问题,提出了一种基于旋转块的BM3D图像去噪改进算法.新算法首先对参考块进行不同角度的旋转获取旋转块,通过旋转块进行相似块匹配过程;然后使用低秩正则化来代替传统算法中的硬阈值滤波;最后,对结合旋转块匹配与低秩正则化的BM3D算法进行自适应调整,从而改善在均匀图像区域中的去噪效果.实验结果表明,新算法的相似块匹配程度更高,峰值信噪比相较于经典算法平均提升0.5 dB,有效保留图像边缘和纹理细节.

Improved Algorithm of BM3D Image Denoising Based on Rotating Block

To address the problems of large similar block matching errors and insufficient protection of image details in the classical BM3D denoising algorithm, an improved BM3D image denoising algorithm based on rotated blocks is proposed. The new algorithm firstly rotates the reference block at different angles to obtain the rotating block, and then performs the similar block matching process through the rotating block; then uses low-rank regularization to replace the hard threshold filtering in the traditional algorithm; finally, the BM3D algorithm combining rotated block matching and low-rank regularization is adaptively adjusted to improve the denoising effect in uniform image regions. Experimental results show that the new algorithm has a higher matching degree of similar blocks, and the peak signal to noise ratio (PSNR) is improved by 0.5dB on average compared with the classical algorithm, effectively preserving image edges and texture details.