This paper addresses the problem of extracting three-dimensional geometric information from a single, uncalibrated image of a scene. This work, building upon [7], is divided into two parts. The first part describes, in simple steps, the basic algorithms to obtain partial or complete geometric reconstruction from single perspective images of a scene. The second part presents a panorama of applications of single-view metrology and discusses its relationship with different disciplines such as architecture, history of art and forensic science. Furthermore, techniques for increasing the level of automation of the reconstruction process are herein described. Several examples on photographs and historical paintings demonstrate the power and flexibility of the proposed techniques.