AFFINE INVARIANT FEATURES IN PATTERN RECOGNITION

Affine invariant feature extraction is an important topic particularly in image recognition applications. This chapter investigates the area of affine invariant feature construction, and introduces a recently proposed multiscale framework for systematically enhancing the performance of the previous methods. The idea in the approach presented is to extend the given pattern to a set of affine covariant versions, each carrying slightly different information, and then to apply known affine invariants to each of them separately. The key part of the framework is the construction of the affine covariant set, and this is done by combining scaled representations of the original pattern. The application of the multiscale framework is demonstrated by constructing several new affine invariant methods, which are compared to the existing approaches in the experiments.