Introduction

Projection of a 3D scene onto a 2D image, in other words using a camera, eliminates information about how far scene objects are from the photographer. But in some cases, 3D information can be restored. This requires not only knowing information about objects or camera configuration, but also having a camera's intrinsic parameters. This chapter sheds light on all the necessary steps for getting 3D information for 2D images, from camera calibration to 3D object position reconstruction and depth map retrieval.