结合分块噪声估计的字典学习图像去噪算法  

Image denoising algorithm combined with dictionary learning and blocked-based noise estimation

作　　者：汪浩然[1] 夏克文[1] 牛文佳[1] 任苗苗[2,3] 李绰 

机构地区：[1]河北工业大学电子与信息工程学院,天津300401 [2]中国科学院电子学研究所,北京100190 [3]中国科学院大学,北京100190

出　　处：《计算机应用研究》2017年第10期3153-3156,3161,共5页Application Research of Computers

基　　金：国家自然科学基金资助项目(51208168);天津市自然科学基金资助项目(13JCYBJC37700);河北省自然科学基金资助项目(E2016202341);大学生创新创业训练计划项目(河北省重点)(201510080051)

摘　　要：近年来K-SVD字典学习去噪算法因其耗时短、去噪效果好的特点得到广泛关注和应用,但该算法的适用条件为图像的噪声为加性噪声且噪声标准差已知。针对这一情况,先提出一种平滑图像块筛选方法,并将其与奇异值分解(singular value decomposition,SVD)相结合实现对图像的噪声标准差估计;再将得到的噪声估计方法与K-SVD字典学习去噪算法结合起来,提出一种具备噪声估计特性的K-SVD字典学习去噪算法。对多种图像的去噪实验结果表明,与Donoho小波软阈值去噪算法、全变分(total variation,TV)去噪算法相比,该算法不仅能够使去噪后图像的峰值信噪比提升1~3 dB,并且能较好地保留图像的细节信息和边缘特征。In recent years, the K-SVD dictionary learning denoising algorithm has been widely concerned and applied because of its short time consuming and outstanding performance. But the application of this algorithm requires that the noise in image is additive noise and standard deviation of the noise is known. In view of this situation, this paper proposed a method to select the smooth image blocks and combined it with the singular value decomposition （SVD） to achieve the estimation of the noise standard deviation of the image. Then it proposed a new denoising algorithm which had the characteristic of noise estimation combining with the obtained noise estimation method and the K-SVD dictionary learning denoising algorithm. Experimental resuits of denoising some images show that, compared with Donoho wavelet soft threshold denoising algorithm and the total variation （TV） denoising algorithm, not only the peak signal to noise ratio（PSNR） of the image denoised by the proposed algorithm is improved by about 1 - 3 dB, but also the detailed information and edge features of the image can be better preserved.

关 键 词：图像去噪 平滑图像块 奇异值分解 噪声估计 字典学习 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]