Optic disc detection is important in the computer-aided analysis of retinal images. It is crucial for the precise identification of the macula to enable successful grading of macular pathology such as diabetic maculopathy. However, the extreme variation of intensity features within the optic disc and intensity variations close to the optic disc boundary presents a major obstacle in automated op...

Design/methodology/approach – Two tests were performed, one on Acoustic Emission artificial signals generated on a CFRP plate and one on an Acousto Ultrasonic setup used for actively detecting impact damage. The waveforms were represented using a data reduction technique based on the Daubechies wavelet and an image processing technique using Chebyshev moments approximation, to get 32 descriptor...

The differentiation matrix for a Daubechies-based wavelet basis defined on an interval will be constructed. It will be shown that the differentiation matrix based on the currently available boundary constructions does not maintain the superconvergence encountered under periodic boundary conditions. BJgy .. .. . .. .A0000 w__ •t!ar ~'..,-

We resolve a long-standing question on completeness of the nonorthogonal Mexican hat wavelet system, in L for 1 < p < 2 and in the Hardy space H for 2/3 < p ≤ 1. Tools include the discrete Calderón condition, a generalization of the Daubechies frame criterion to a weighted L space, and imbeddings of that weighted space into L and Hardy spaces.

By rewriting the projection operator P 0 in wavelets in another formula, we obtain a characterization of dimJ V 0 (x) where V 0 is a ?-shift-invariant subspace of L 2 (R n) derived from a dual wavelet basis and prove that there does not exist a wavelet function 2 L 2 (R) such that ^ has compact support and k2Z Z (supp ^ + 4k) = R up to a zero subset of R. x1. Deenitions and Main Results In I.Da...

We initially discuss a new and simple method of parameterization of compactly supported biorthogonal wavelet systems with more than one vanishing moment. To this end we express both primal and dual scaling function filters (low pass) as products of two Laurent polynomials. The first factor ensures required vanishing moments and the second factor is parameterized and adjusted to provide required...

In this paper de-noising techniques are investigated in connection with secure wideband chaotic communication systems. An alternate version of the recently proposed Ueda chaotic communication system based on the initial condition modulation (ICM) of the chaotic carrier by the binary message to be transmitted is proposed and evaluated in the presence of noise, demonstrating a significant improve...

This paper describes WBIIS (Wavelet-Based Image Indexing and Searching), a new image indexing and retrieval algorithm with partial sketch image searching capability for large image databases. The algorithm characterizes the color variations over the spatial extent of the image in a manner that provides semanticallymeaningful image comparisons. The indexing algorithm applies a Daubechies' wavele...

Over the past few decades, the demand for digital information has increased drastically. This enormous demand poses serious difficulties on the storage and transmission bandwidth of the current technologies. One possible solution to overcome this approach is to compress the amount of information by discarding all the redundancies. In multimedia technology, various lossy compression techniques a...

Machine learning of ECG is a core component in any of the ECG-based healthcare informatics system. Since the ECG is a nonlinear signal, the subtle changes in its amplitude and duration are not well manifested in time and frequency domains. Therefore, in this chapter, we introduce a machine-learning approach to screen arrhythmia from normal sinus rhythm from the ECG. The methodology consists of ...