Quasi-Shift-Invariant Complex Discrete Wavelet Transfrom and Its Industrial Applications

2014 Fiscal Year Final Research Report

• Project/Area Number: 24560515
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Measurement engineering
• Research Institution: The University of Electro-Communications
• Principal Investigator: NAKANO Kazushi 電気通信大学, 情報理工学(系)研究科, 教授/副学長 (90136531)
• Co-Investigator(Kenkyū-buntansha): SHIN Seiichi 電気通信大学, 情報理工学研究科, 教授 (20134463)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: ウェーブレット変換 / 複素離散ウェーブレット / 並進不変性 / CQFバンク / 疑似並進不変性

Outline of Final Research Achievements

We focus on the Shift-Invariance (SI) in the Complex Discrete Wavelet Transform (CDWT). Our results about the SI of CDWT using the conjugate quadrature filter (CQF) bank are as follows: (1) By adding another condition to the existing well-known condition half-sample shifts of Low-pass filters, we clarified a method for constructing the perfect SI in theory. The additional condition is for establishing the relationship of half-sample shifts between real/imaginary inputs.(2) We proposed the implementation of new CDWT based on above (1), and named it the quasi-shiftinvariant (QSI) CDWT. (3) We factored filters of QSI-CDWT into lifting steps. (4) From three experiments with an application to image processing, we demonstrated that our method has higher SI than conventional SI-CDWT.

Free Research Field

計測制御工学