Generalized unequal length lapped orthogonal transform for subband image coding

Takayuki Nagai, Masaaki Ikehara, Masahide Kaneko

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)


In this paper, generalized linear phase lapped orthogonal transforms with unequal length basis functions (GULLOTs) are considered. The length of each basis of the proposed GULLOT can be different from each other, whereas all the bases of the conventional GenLOT are of equal length. In general, for image coding application, the long basis for a low-frequency band and the short basis for a high-frequency one are desirable to reduce the blocking and the ringing artifact simultaneously. Therefore, the GULLOT is suitable especially for a subband image coding. In order to apply the GULLOT to a subband image coding, we also investigate the size-limited structure to process the finite length signal, which is important in practice. Finally, some design and image coding examples are shown to confirm the validity of the proposed GULLOT.

Original languageEnglish
Pages (from-to)3365-3378
Number of pages14
JournalIEEE Transactions on Signal Processing
Issue number12
Publication statusPublished - 2000 Dec
Externally publishedYes

ASJC Scopus subject areas

  • Signal Processing
  • Electrical and Electronic Engineering


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