Filter banks for less ringing artifacts

Wataru Asano, Tomoaki Takeuchi, Masaaki Ikehara

    Research output: Contribution to journalArticlepeer-review

    Abstract

    In image compression using a filter bank, blocking can be reduced by overlapping the basis functions in the lapped orthogonal transform or the lapped biorthogonal transform, whereas ringing can be conspicuous. In this paper, two methods are proposed to suppress ringing while blocking is reduced. One of them uses an unequal length linear phase biorthogonal filter bank. This is an extension of the unequal length orthogonal transform to the biorthogonal type and a generalization of the filter length in the lapped biorthogonal transform. This filter bank can be realized with a lattice structure. By reducing the length of the high-frequency filter on the synthesis side, ringing is compressed to the edge so that it is less visible. Another method introduces the peak-to-peak ratio into the performance criterion of the filter bank design. In this method, ringing can be suppressed by restricting the impulse response of the filter. By means of these methods, ringing can be reduced while coding performance is retained in comparison with the conventional equal length filter banks.

    Original languageEnglish
    Pages (from-to)1-10
    Number of pages10
    JournalElectronics and Communications in Japan, Part III: Fundamental Electronic Science (English translation of Denshi Tsushin Gakkai Ronbunshi)
    Volume85
    Issue number6
    DOIs
    Publication statusPublished - 2002 Jun 1

    Keywords

    • Biorthogonal filter bank
    • Image processing
    • Ringing
    • Unequal length

    ASJC Scopus subject areas

    • Electrical and Electronic Engineering

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