一种改进的小波域阈值去噪算法

Improved Algorithm for Threshold De-Noising in Wavelet Transform Domain

在D.L.Donoho和I.M.Johnston提出的多分辨分析小波阈值去噪方法的基础上,提出了一种新的双变量阈值函数。采用新的阈值函数的去噪效果无论在视觉效果上,还是在信噪比增益上和最小均方意义上均优于传统的硬阈值和软阈值,克服了采用硬阈值法去噪效果不佳和软阈值法过度光滑使信号失真的缺点。通过仿真实验结果,表明该方法的有效性和优越性。

Based on Multiresolution analysis wavelet threshold de-noising method which put forward by D. L. Donoho and I. M.. Johnston, a new bivariate threshold function is posed. The de-noising method adopting the new threshold function gives better MSE performance and SNR gains than that of hard and soft thresholding methods. However, the hard thresholding is best in preserving edges but worst in de-noising, and soft thrsholding is best in reducing noise but worst in preserving edges, this method incorporates the hard and soft thresholding to achieve a compromise between the two methods. Numerical simulations show that this de-noising method is effective and excellent.