Design of linear phase with unequal length paraunitary filter banks with suboptimal coding gain

A. Ochi, Y. Kobayashi, M. Ikehara

Research output: Chapter in Book/Report/Conference proceedingConference contribution


In this paper, we present a design of M-channel linear-phase paraunitary filter banks (LPPUFB), with filters of unequal lengths and same center of symmetry, (ULPPUFB) without using non-linear optimization algorithms. ULPPUFB can be viewed as generalized lapped orthogonal transforms (GenLOTs) with variable-length basis functions and are used in block transform-based image coding. ULPPUFB has long basis functions in order to avoid blocking artifacts, whereas it reserves short basis functions for high-frequency signal components like edges, thereby limiting ringing artifacts. The design of ULPPUFB has already been shown and can be expressed completely using a lattice structure. However, when it is used in image coding, the coding gain must be maximization, and then we must use non-linear optimization algorithms. When filter length or channel numbers are increased, non-linear optimization algorithms would necessitate an enormous amount of calculation. In this paper, we design each filter without using non-linear optimization, directly based on the compaction problem and implement ULPPUFB by changing these filters into lattice structures. Then, we show their validity.

Original languageEnglish
Title of host publicationIEEE Asia-Pacific Conference on Circuits and Systems, Proceedings, APCCAS
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages6
ISBN (Print)0780376900
Publication statusPublished - 2002
EventAsia-Pacific Conference on Circuits and Systems, APCCAS 2002 - Denpasar, Bali, Indonesia
Duration: 2002 Oct 282002 Oct 31


OtherAsia-Pacific Conference on Circuits and Systems, APCCAS 2002
CityDenpasar, Bali


  • Algorithm design and analysis
  • Band pass filters
  • Channel bank filters
  • Compaction
  • Design optimization
  • Discrete cosine transforms
  • Filter bank
  • Image coding
  • Lattices
  • Low pass filters

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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