A design method of 2-D maximally flat diamond-shaped half-band FIR filters with rectangular support of impulse response

The authors discuss a design of 2-D diamond-shaped half-band FIR (finite impulse response) filters with rectangular support of the impulse response. The difference of the filter lengths with respect to both axes is restricted to 2, 4, and 6 in the present work, because it is very difficult to derive a general design method for an arbitrary difference. The proposed method is very simple because the design is completed simply by solving a set of linear simultaneous equations whose solution represents the impulse response coefficients directly. Several design examples are given to show the validity of the approach