QGIS plugin or web app? Lessons learned in the development of a 3D georeferencer

Collections of historical images are currently being scanned to stop their degradation and to enable a numeric exploitation. These collections have a high cultural, artistic and scientific value. However, they are not fully exploited because the photographs do not have a georeference (geographic information cannot be extracted from the picture) and are poorly labeled (makes searching in a database inefficient). During the last years, we developed a QGIS plugin and a web app dedicated to the georeferencing of photographs and the linking of images with spatial data. In this paper, we discuss the technologies involved and compare both implementations. The results suggest that both approaches are valuable but provide different advantages in term of target users and development effort.