改进的软阈值法去噪效果分析  

Denoising analysis of improved soft threshold method

作　　者：任超[1] 焦元元[1] 孙昌瑜[1] 吴伟[1] 

机构地区：[1]桂林理工大学测绘地理信息学院/广西空间信息与测绘重点实验室,广西桂林541004

出　　处：《测绘科学》2013年第1期10-12,共3页Science of Surveying and Mapping

基　　金：国家自然科学基金项目(41071294);广西自然科学基金资助项目(桂科自0640178);广西科学基金资助项目(桂科基0991023)

摘　　要：本文针对固定阈值法对信号去除噪声会出现"过扼杀"小波系数的现象,提出一种改进的阈值公式,进而给出改进的软阈值法。理论分析、工程实例的结果表明:改进的软阈值法无论在去噪效果上,还是在信噪比和均方根误差意义上均优越于硬、软阈值法,同时还有效地克服了软阈值中的估计小波系数和带噪小波系数间的恒定偏差问题。For fixed threshold method for removing noise of the signal could produce the phenomenon of ＂over-killing＂ wavelet coefficients, an improved threshold formula was presented, and thus an improved soft threshold method was given in the paper. The re- sults of theoretical analysis and engineering projects showed that： the improved soft-threshold method in terms of denoising effect, or SNR and RMSE are superior to the hard or soft threshold method. At the same time, it could be used effectively to overcome the constant deviation between the estimated wavelet coefficients and noise wavelet coefficients in soft threshold.

关 键 词：阈值 阈值函数 信噪比 均方根误差 

分 类 号：P228.41[天文地球—大地测量学与测量工程]