Computation of wavelet coefficients from average samples

نویسندگان

  • Gerardo Pérez-Villalón
  • A. Portal
چکیده

There exist efficient methods to compute the wavelet coefficients of a function f(t) from its point samples f ( T [n + τ ] ) , n ∈ N. However, in many applications the available samples are average samples of the type ∫∞ −∞ f ( T [t + n + τ ] ) u(t)dt, where the averaging function u(t) reflects the characteristic of the acquisition device. In this work, methods to compute the coefficients in a biorthogonal wavelet system from average samples are studied. Error estimations are obtained and using them, the optimal values for the parameters in the proposed approximation rules are calculated. The obtained error estimations can also be applied to the rules that compute the coefficients from point samples, and thus, these estimations can be used to compare and to choose between the different methods proposed in the literature. The methods proposed here also allow to compute the biorthogonal wavelet coefficients from the coefficients in another biorthogonal wavelet system.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Structure of Wavelet Covariance Matrices and Bayesian Wavelet Estimation of Autoregressive Moving Average Model with Long Memory Parameter’s

In the process of exploring and recognizing of statistical communities, the analysis of data obtained from these communities is considered essential. One of appropriate methods for data analysis is the structural study of the function fitting by these data. Wavelet transformation is one of the most powerful tool in analysis of these functions and structure of wavelet coefficients are very impor...

متن کامل

Fast Kirchhoff migration in the wavelet domain

We present results of the application of the wavelet transform method to seismic imaging. The objective of this research is to develop 3D seismic Kirchhoff imaging in the wavelet-transform domain, making use of the time-frequency property of wavelets. We propose to migrate the wavelets as units rather than single samples as in conventional Kirchhoff migration implementation. In practice, the wa...

متن کامل

Automatic classification of normal and abnormal cardiac sounds by combining features based on wavelet transform and capstral coefficients extracted from PCG signals (Research Article)

Cardiac sounds are produced by the mechanical activities of the heart and provide useful information about the function of the heart valves. Due to the transient and unstable nature of the heart's sound and the limitation of the human hearing system, it is difficult to categorize heart sound signals based on what is heard from a stethoscope. Therefore, providing an automated algorithm for prima...

متن کامل

A Novel Approach of Wavelet Packet Transform for Knock Signal Analysis

The computation complexity dominates Continuous Wavelet Transform (CWT) and the low frequency resolution limit the Discrete Wavelet Transform (DWT). The degradation in frequency resolution in Discrete Wavelet Transform (DWT) is due to the fact, that, DWT decomposes only the approximation coefficients at each level. This detail is not enough to analyse the signal like knock in the engine. The ac...

متن کامل

Analysis and localization of epileptic events using wavelet packets.

This article compares results obtained in previous studies using time-frequency representations (Wigner-Ville, Choi-Williams and Parametric) and the wavelet transform with those obtained with wavelet packet functions to show new findings about their quality in the analysis of ECoG recordings in human intractable epilepsy: data from 21 patients have been analyzed and processed with four types of...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • J. Computational Applied Mathematics

دوره 248  شماره 

صفحات  -

تاریخ انتشار 2013