Design of 2-D digital filters with rectangular passbands and stopbands

A modified version of a configuration proposed by K. Hirano and J.K. Aggarwal (1978) for the design of 2-D digital filters with rectangular stopbands is suggested, and sufficient conditions for its correct operation are derived. These conditions are used to show that the nine possible stopbands can be realized by using standard 1-D continuous low-pass, bandpass, or high-pass transfer functions that can be derived from classical analog-filter approximations.<
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