Feature Extraction and Image Processing

5

161

Feature extraction by

shape matching

5.1 Overview

High-level feature extraction concerns finding shapes in computer images. To be able to

recognise faces automatically, for example, one approach is to extract the component

features. This requires extraction of, say, the eyes, the ears and the nose, which are the

major face features. To find them, we can use their shape: the white part of the eyes is

ellipsoidal; the mouth can appear as two lines, as do the eyebrows. Shape extraction

implies finding their position, their orientation and their size. This feature extraction process

can be viewed as similar to the way we perceive the world: many books ...