CAJ | 학술논문

文中在D. L. Donoho和I. M. Johnstone提出的小波阈值去噪基础上，提出了一种改进的阈值函数。该阈值函数采用双阈值模式，通过逐渐增大对小波系数的缩减力度来处理双阈值之间的小波系数，尽可能多地保留有用信息，直至小波系数缩减为零。在这里引入了一个控制变量来调节系数的缩减幅度。与传统的软、硬阈值方法相比，改进的阈值函数最大的优点是函数连续且减小了估计系数的误差。通过仿真实验，从视觉和客观评价标准(峰值信噪比和均方根误差)上验证了新阈值函数去噪的有效性。
문중재D. L. Donoho화I. M. Johnstone제출적소파역치거조기출상，제출료일충개진적역치함수。해역치함수채용쌍역치모식，통과축점증대대소파계수적축감력도래처리쌍역치지간적소파계수，진가능다지보류유용신식，직지소파계수축감위령。재저리인입료일개공제변량래조절계수적축감폭도。여전통적연、경역치방법상비，개진적역치함수최대적우점시함수련속차감소료고계계수적오차。통과방진실험，종시각화객관평개표준(봉치신조비화균방근오차)상험증료신역치함수거조적유효성。
An improved threshold function is presented based on the wavelet shrinkage put forward by D. L. Donoho and I. M. Johnstone. This function has two thresholds,it retains the useful information as much as possible by gradually increasing the shrink of wavelet coeffi-cients between the two thresholds,until the coefficients are reduced to zero. In this paper,introduce a control variable to adjust the shrink. Compared with the traditional soft and hard threshold methods,the greatest superiority of this new function is continuous and reducing the error of estimated coefficient. Finally,demonstrate and validate the denoising effect of this new threshold function by simulation experi-ment from vision and objective evaluation standards ( Peak Signal to Noise Ratio and Root-Mean-Square Error) .