This book contains material for an introductory course on homogeneous representations for geometry in 2 and 3 dimensions, camera projections, representations of 3D rotations, epipolar geometry, and estimation of various type of geometric objects. Based on these results, a set of applications are presented.  It also contains a toolbox of general results that are useful for the presented material.  The book is intended for undergraduate studies at advanced level in master programs, or in PhD-courses at introductory level.