Linear Filters and Frequency Analysis

Abstract

This chapter reviews some classical image analysis tools: linear filtering, linear bases, frequency analysis, and space-frequency analysis. Some of the basic ideas are illustrated in Fig. 2.1. These basic methods need to be understood before the results of statistical image models can be fully appreciated. The idea of processing of different frequencies is central in the reviewed tools. Therefore, a great deal of the following material is devoted to explaining what a frequency-based representation of images is, and why it is relevant in image analysis.