Boundary handling mechanism for lifting-based spatial adaptation of filter banks

Abstract

Time/space varying filter banks (FBs) are proved to be useful in building signal adaptive transforms. Lifting factorization of FBs allows to spatially adapt between arbitrary FBs, avoiding the need to design border FBs to complete perfect reconstruction (PR) during the transition. However, lifting based switching between arbitrarily designed FBs induces spurious transients into the resulting subbands during the transition. In this paper we propose a boundary handling mechanism that maintains good frequency response and eliminates the transients during the transition. We successfully show spatial adaptation between JPEG2000 9/7 and 5/3 FBs to reduce the ringing artifacts in images.