Lifting structures for quincunx FIR filter-banks with quadrantal or diagonal symmetry

Abstract

Lifting structures, also referred to as ladder structures, have been used for the design of linear phase (centro-symmetric) 2-D Quincunx filter-banks. In this letter, our aim is to use lifting structures for the construction of Quincunx filter-banks with the filters having the higher order symmetries viz. quadrantal or diagonal symmetries. We derive conditions on the predict and update steps of the lifting structure so that the filters in the filter-bank have quadrantal or diagonal symmetry. Using these conditions, we construct example structures for the predict and update steps which yield Quincunx filter-banks with quadrantally or diagonally symmetric filters.