Two-fold symmetric diamond-shaped 2-D filter design with quincunx sampling application

This paper presents the design of a two-fold symmetric, linear-phase, diamond-shaped FIR filter. The design is based on a Semi-Definite Program (SDP) of moderate dimension in which the passband and the stopband are expressed as intersecting regions of second order trigonometric polynomials. The two-fold symmetric filter is a more general representation when compared with its four-fold symmetric counterpart but it has much higher complexity and involve more complicated trigonometric functions. However the performance of the filter outperforms all the currently available filter designs and its effectiveness is emphasized by an example of quincunx sampling application presented at the end of this paper.