基于Walsh-Hadamard投影的快速Nonlocal-Means图像去噪  

Fast Nonlocal-Means Image Denoising Method Based on Walsh-Hadamard Projection

作　　者：张志[1,2] 王润生[2] 

机构地区：[1]空军装备研究院,北京1000851 [2]国防科技大学ATR实验室,长沙410073

出　　处：《宇航学报》2011年第2期380-387,共8页Journal of Astronautics

基　　金：国家自然科学基金(60902088)

摘　　要：针对Nonlocal-means图像去噪算法计算强度较高的问题,提出了一种投影加速算法。分析了Nonlo-cal-means算法的计算瓶颈,利用Walsh-Hadamard变换的快速运算和自递归特性,使用一组完备的Walsh-Hadamard变换将图像块投影到其张成的空间中;利用Walsh-Hadamard投影的能量集中特性和匹配计算过程中的拒绝策略,在Nonlocal-means去噪算法的图像块匹配计算中快速丢弃无法匹配的图像块。实验结果表明,该算法获得了较好的加速性能,且去噪效果没有受到影响。A fast Nonlocal-means image denoising method with projection is proposed.After analyzing the bottleneck of Noncal-means,the fast and auto-recursive computation of Walsh-Hadamard transform is used to project the image blocks into Walsh-Hadamard space.Because of efficient energy packing of Walsh-Hadamard projection,the algorithm can fast discard those impossible blocks by using a rejection scheme in the matching procedure of image blocks in the Nonlocal-means image denoising method.Experimental results show that the proposed method can accelerate the Nonlocal-means algorithm without image quality degradation.

关 键 词：图像处理 图像去噪 投影 Nonlocal-means Walsh-Hadamard变换 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]