Image Feature Extraction and Evaluation

This chapter introduces the detection algorithms for visual features commonly used in visual servoing applications. The type of visual features addressed here are point features and image moments. For the point features detection, two point operators are presented, Harris operator and SIFT descriptor. Image moment is another type of visual feature that can be used to describe the objects from the image and bring in some advantage as to decouple the non-linearities introduced by the interaction matrix. The chapter also includes the performance evaluation of the visual features in several servoing applications. The performance of the point features was analysed using criteria such as stability, repeatability and features spread. The evaluation of image moments was performed using a criterion based on Hausdorff distance. Finally, all the algorithms were implemented and tested for different servoing scenarios.