Chapter 5 Fast and Efficient Local Features Detection for Building Recognition

The vast growth of image databases creates many challenges for computer vision applications, for instance image retrieval and object recogni- tion. Large variation in imaging conditions such as illumination and geomet- rical properties (including scale, rotation, and viewpoint) gives rise to the need for invariant features; i.e. image features should have minimal differ- ences under these conditions. Local image features in the form of key points are widely used because of their invariant properties. In this chapter, we ana- lyze different issues relating to existing local feature detectors. Based on this analysis, we present a new approach for detecting and filtering local features. The proposed approach is tested in a real-life application which supports navigation in urban environments based on visual information. The study shows that our approach performs as well as existing methods but with a significantly lower number of features.