Construction of 2D wavelets with directionality
Tadashi Matsuo, Yasuo Yoshida, Nobuyuki Nakamori · Electronics and Communications in Japan (Part III Fundamental Electronic Science) · 2004
The two-dimensional wavelet transform usually used applies one-dimensional wavelet transforms in the vertical and horizontal directions. By carrying out the wavelet transform, the local frequency can be analyzed and manipulated. However, when two-dimensional extension is performed by means of one-dimensional transforms in the vertical and horizontal directions, the components at 45° and 135° cannot be distinguished. The method proposed in this paper allows local processing corresponding to four or six directions by combining the wavelet transform and perfectly reconstructable filters. In this paper, the proposed method is described and its effectiveness is demonstrated by simulation of noise elimination. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 88(3): 1–10, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20129