English

Directional wavelet packets originating from polynomial splines

Numerical Analysis 2020-08-13 v1 Numerical Analysis

Abstract

The paper presents a versatile library of quasi-analytic complex-valued wavelet packets (WPs) which originate from polynomial splines of arbitrary orders. The real parts of the quasi-analytic WPs are the regular spline-based orthonormal WPs designed in [1]. The imaginary parts are the so-called complementary orthonormal WPs that are derived from the Hilbert transforms of the regular WPs and, unlike the symmetric regular WPs, are antisymmetric. Tensor products of 1D quasi-analytic WPs provide a diversity of 2D WPs oriented in multiple directions. For example, a set of the fourth-level WPs comprises 62 different directions. The properties of the presented WPs are refined frequency resolution, directionality of waveforms with unlimited number of orientations, (anti-)symmetry of waveforms and windowed oscillating structure of waveforms with a variety of frequencies. Directional WPs have a strong potential to be used in various image processing applications such as restoration of degraded images and extraction of characteristic features from the images.

Keywords

Cite

@article{arxiv.2008.05364,
  title  = {Directional wavelet packets originating from polynomial splines},
  author = {Amir Averbuch and Pekka Neittaanmaki and Valery Zheludev},
  journal= {arXiv preprint arXiv:2008.05364},
  year   = {2020}
}

Comments

26 pages, 18 figures. arXiv admin note: substantial text overlap with arXiv:1907.01479, arXiv:2001.04899

R2 v1 2026-06-23T17:48:34.158Z