线性相位二维递归数字滤波器组的设计

提出一种线性相位二维递归数字滤波器组的设计方法.这种设计是以 S 域一维(1-D)贝塞尔函数为原型的低通滤波器的传递函数,通过一维 S 域至二维 Z 域的双线性变换,实现线性相位二维递归数字滤波器.所实现的二维数字滤波器不仅保持贝塞尔滤波器通带内相位线性、阻带内相位近似线性的优点,而且能利用一维至二维的双线性变换压缩过渡带,使过渡带变得陡峭、阻带衰减增加.采用本文的设计方法,利用低阶的线性相位递归数字滤波器组,即可实现高性能的二维分析与综合数字滤波器组,完成图象的子带分割与重建功能.计算机仿真实验证明所提出的设计方法是正确的、有效的.

Design of 2-D Recursive Digital Filter Banks with Linear Phase

A design approach cf linear phase 2-D recursive digital filter banks has been proposed in the paper.The design is based on the transfer function which adopts the Besel function of S domain as its original lowpass filter.By bilinear transformation of 1-D S domain to 2-D Z domain to the function,a linear phase 2-D recursive digital filter can be realized.The realized 2-D IIR filters not only keep the advantages of the linear phase charateristics in the pass band and approximately linear phase charateristics in the stop band,but also compress the transition band to be steep and increase the attenuation of stop- band.Accordiog to the approach presented here,qualified 2-D analysis and synthesis IIR digital filter banks can be realized by lower order ones to accom- plished the function of image separation and reconstruction.Computer simulation results proved that the design is correct and effective.