Maximally flat nonrecursive two-dimensional digital filters
Maximally flat nonrecursive two-dimensional digital filters
复制标题
最大平坦非递归二维数字滤波器
DOI：
10.1109/tcs.1974.1083864
复制
发表时间：
1974
期刊：
影响因子：
--
通讯作者：
J. Thiran
中科院分区：
文献类型：
--
作者：
Y. Kamp;J. Thiran
本文将最大平坦准则推广到近似圆对称低通特性的二维非递归数字滤波器的设计。一维方法的简单推广并不完全指定滤波器的系数矩阵。附加的自由度可以用于局部地增加原点和/或奈奎斯特频率处的平坦度的阶数。局部条件的选择是至关重要的，特别是对于轴外的单调行为。在频率平面的对角线上的局部条件的集中给出了一类特殊的滤波器，除了系数的封闭形式表达式的优点之外，其具有沿频率平面的任何半径沿着单调减小的频率响应。
The maximally flat criterion is extended to the design of two-dimensional nonrecursive digital filters which approximate circularly symmetrical low-pass specifications. Straightforward generalization of the one-dimensional method does not completely specify the coefficient matrix of the filter. The additional degrees of freedom can be used to increase locally the order of flatness at the origin and/or at the Nyquist frequencies. The choice of the local conditions is crucial, in particular for what regards the monotonic behavior outside the axes. Concentration of the local conditions on the diagonal of the frequency plane gives a special class of filters which, besides the advantage of closed-form expressions for the coefficients, has a monotonically decreasing frequency response along any radius of the frequency plane.