“…The task of coarsely estimating the place where a photo was taken based on a set of previously visited locations is called Visual (Image) Geo-localization (VG) [37,42,86] or Visual Place Recognition (VPR) [21,44] and it is addressed using image matching and retrieval methods on a database of images of known locations. We are witnessing a rapid growth of this field of research, as demonstrated by the increasing number of publications [2,10,14,[22][23][24]28,30,36,37,42,44,46,57,60,72,73,[76][77][78][79]81,87], but this expansion is accompanied by two major limitations: i) A focus on single metric optimization, as it is common practice to compare results solely based on the recall on chosen datasets and ignoring other factors such as execution time, hardware requirements, and scalability. All these aspects are important constraints in the design of a real-world VG system.…”