CAJ | 학술논문

针对硬阈值函数在阈值处不连续，重构信号易产生振荡，以及软阈值函数的量化值与原始小波系数有恒定的偏差不能逼近的问题，提出了一种既能在阈值处连续，又能实现逼近原始小波系数的改进型阈值函数。仿真结果显示将改进型的阈值函数用于信号滤波，在均方误差和信噪比方面都优于传统的两种阈值函数。
침대경역치함수재역치처불련속，중구신호역산생진탕，이급연역치함수적양화치여원시소파계수유항정적편차불능핍근적문제，제출료일충기능재역치처련속，우능실현핍근원시소파계수적개진형역치함수。방진결과현시장개진형적역치함수용우신호려파，재균방오차화신조비방면도우우전통적량충역치함수。
According to the fact that oscillation occurs in the reconstruction signal because of discontinuous threshold function at threshold point and the fact that an approximate problem arises owing to the permanent bias between quan-tized value of soft threshold function and original wavelet coefficient, a modified threshold function is proposed. The modified function is continuous at threshold point and can approximate the original wavelet coefficient. The results of simulation demonstrate that the modified threshold function is superior to traditional methods in both MSE and SNR.