A Linear Optimization of Dual-Tree Complex Wavelet Transform

Seisuke KYOCHI  Takafumi SHIMIZU  Masaaki IKEHARA  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E94-A    No.6    pp.1386-1393
Publication Date: 2011/06/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.E94.A.1386
Print ISSN: 0916-8508
Type of Manuscript: PAPER
Category: Digital Signal Processing
dual-tree complex wavelet transform,  half sample delay condition,  directionality,  shift invariance,  least squares method,  

Full Text: PDF(958.9KB)>>
Buy this Article

In this paper, a linear optimization of the dual-tree complex wavelet transform (DTCWT) based on the least squares method is proposed. The proposed method can design efficient DTCWTs by improving the design degrees of freedom and solving the least square solution iteratively. Because the resulting DTCWTs have good approximation accuracy of the half sample delay condition and the stopband attenuation, they provide precise shift-invariance and directionality. Finally, the proposed DTCWTs are evaluated by applying to non-linear approximation and image denoising, and showed their effectiveness, compared with the conventional DTCWTs.