Object recognition has been an area of extensive research for a long time. During the last decades, a large number of algorithms have been proposed. This is due to the fact that, at a closer look, "object recognition" is an umbrella term for different algorithms designed for a wide variety of applications, where each application has its specific requirements and constraints. This book demonstrates the diversity of applications and highlights some important algorithm classes by presenting representative example algorithms for each class. This book is written in a tutorial style and is therefore suitable as an introduction into the field of object recognition for interested readers who are not yet experts. The presentation of each algorithm focuses on the main idea, which is described in detail, and avoids extensive usage of mathematics. Graphic illustrations of the algorithm flow facilitate understanding. The algorithms presented are classified according to the following categories: global approaches, transformation-search-based methods, geometrical model driven methods, 3D object recognition schemes, flexible contour fitting algorithms and feature-based methods. Typical example algorithms are presented for each of the categories.