Directional Filter Banks Designed From Zero-Phase Low-Pass Filters

This work proposes an analytic technique for designing 2D wedge-shaped filters which can be regarded as components of an uniform directional filter bank. The design starts from a zero-phase low-pass prototype filter, to which a specific frequency transformation is applied to obtain wedge filters. A correction low-pass filter may be used to remove some marginal distortions in the filter frequency response. Finally, the 2D wedge filter transfer function results directly in factored form, which is an advantage in implementation. Moreover, the 2D wedge filter function is parametric and can be tuned according to the imposed specifications, like orientation and aperture angle.