一种新的小波收缩统一阈值函数  

A New uniform threshold function of wave-shrink

作　　者：李财莲[1] 李志先[2] 孙即祥[1] 康耀红[3] 

机构地区：[1]国防科技大学电子科学与工程学院,湖南长沙410073 [2]洛阳理工学院计算机与信息工程系,河南洛阳471023 [3]海南大学信息科学技术学院,海南海口570228

出　　处：《国防科技大学学报》2012年第1期155-159,共5页Journal of National University of Defense Technology

基　　金：国家自然科学基金资助项目(40901216)

摘　　要：提出一种新的小波收缩统一阈值函数,并证明了新阈值函数具有收敛性,通过调节可变参数的取值可以改变新阈值函数的趋向,为图像阈值去噪的自适应处理提供了可能。此外,给出了新阈值函数的期望、方差与风险的关系式。仿真结果表明新阈值函数不仅能有效去除噪声,而且比两种经典的阈值函数有更高的灵活性,可以获得更高的信噪比和更好的视觉效果。A new uniform threshold function of wave-shrink for image denoising is proposed. The new function has the advantage of satisfying the shrinkage condition. By changing the parameter u, we can change the trend of this new function, which makes it possible to find an adaptive method whenever using the wavelet shrinkage method for image denoising. Finally, efficient formulas for computing mean , variance and risk of the new uniform threshold function are derived. Numerical experiments and comparative studies are performed, demonstrating the effectiveness of our threshold function. Additionally, the proposed new function can also give better performance in terms of both PSNR and in visual quality.

关 键 词：小波变换 硬阈值函数 软阈值函数 统一阈值函数 图像去噪 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]