CAJ | 학술논문

对比研究了D.L.Donoho和I.M.Johnstone提出的小波阈值去噪的硬阈值去噪法和软阈值去噪法的优点和缺点，并在此基础上构造了一个新的阈值函数，它克服了硬阈值处理方法在λ点处不连续及软阈值函数导数不连续的缺点，而且是高阶可导的，在实际应用时能够保留较大的小波系数，从而保留了尽可能多的信号，进而能够获得更好的去噪效果。仿真实验结果显示，新阈值函数可有效地抑制噪声，其去噪后的信噪比和均方根误差均优于软硬阈值函数以及已有的几种改进阈值函数，具有较高的实用价值。
대비연구료D.L.Donoho화I.M.Johnstone제출적소파역치거조적경역치거조법화연역치거조법적우점화결점，병재차기출상구조료일개신적역치함수，타극복료경역치처리방법재λ점처불련속급연역치함수도수불련속적결점，이차시고계가도적，재실제응용시능구보류교대적소파계수，종이보류료진가능다적신호，진이능구획득경호적거조효과。방진실험결과현시，신역치함수가유효지억제조성，기거조후적신조비화균방근오차균우우연경역치함수이급이유적궤충개진역치함수，구유교고적실용개치。
This paper studies the advantages and disadvantages of hard threshold denoising and soft threshold denoising for wavelet denoising proposed by D.L.Donoho and I.M.Johnstone. And construct a new threshold function, it overcomes the point of discontinuity and soft threshold function derivative discontinuous shortcoming of the hard threshold processing method in λ, but also the high order derivative, can retain big wavelet coefficient in the actual application, so as to preserve the signal as much, so to obtain better denoising effect. The simulation results show that, the new threshold function can effectively restrain the noise, the noise of the signal to noise ratio and root mean square error is better than soft and hard threshold function and sev-eral improved threshold function, has a high practical value.