Introduction

Abstract

During the past decade the use of different types of wavelets has to a large extent been dominated by applications to signal analysis and image compression problems. Their potential in numerical schemes for various operator equations has also aroused increasing interest [C, D3]. This is largely due to the fact that wavelet bases or shortly wavelets combine at least three useful properties, namely,

• (I) they constitute a Riesz basis for the relevant function space such as an energy space;

• (II) they can be arranged to be compactly supported;

• (III) they satisfy moment conditions up to a certain order.