摘要
在小波域中分析了传统软阈值法和硬阈值法的特点,并在标准软硬阈值折衷法的基础上,提出了一种软硬阈值改良折衷法.与标准软硬阈值折衷法相比,其阈值函数具有更加灵活多变的形式,便于进行各种数学处理;与传统软阈值法和硬阈值法相比,它克服了硬阈值函数不连续的缺点,减小了软阈值函数中的估计小波系数与分解小波系数之间存在的恒定偏差.仿真实验结果表明,该改良方法的去噪性能优于传统软阈值法、硬阈值法、标准软硬阈值折衷法及一些现有的新阈值函数法.
The characteristics of two traditional wavelet compromise methods, referred to as the soft-thresholding method and the hard-thresholding method, were analyzed in the wavelet domain. A new compromise thresholding method that improves performance is presented, based on the standard compromise threshold method, yet more flex- ible and easier to treat mathematically. Compared with traditional wavelet compromise methods, the new approach avoids the discontinuity of the hard-threshold method and also decreases the fixed bias between the estimated wave- let coefficients and the decomposed wavelet coefficients of the soft-threshold method. Simulation results show that the improved method is better at denoising than the soft-threshold method, the hard-threshold method, the standard compromised threshold method, as well as other threshold function methods.
出处
《智能系统学报》
2008年第3期222-225,共4页
CAAI Transactions on Intelligent Systems
基金
国家自然科学基金资助项目(60674092)
江苏省高技术研究(工业)基金资助项目(BG2006010)
关键词
小波变换
阈值去噪
阈值函数
均方误差
wavelet transform
threshold denoising
threshold function
MSE
