Browsing and Experiencing Repositories of Spatially Oriented Historic Photographic Images

Many institutions archive historical images of architecture in urban areas and make them available to scholars and the general public through online platforms. Users can explore these often huge repositories by faceted browsing or keyword-based searching. Metadata that enable these kinds of investigations, however, are often incomplete, imprecise, or even wrong. Thus, retrieving images of interest can be a cumbersome task for users such as art and architectural historians trying to answer their research questions. Many of these images, often containing historic buildings and landscapes, can be oriented spatially using automatic methods such as “structure from motion” (SfM). Providing spatially and temporally oriented images of urban architecture, in combination with advanced searching and exploration techniques, offers new potential in supporting historians in their research. We are developing a 3D web environment useful to historians enabling them to search and access historic photographic images in a spatial context. Related projects use 2D maps, showing only a planar view of the current urban situation. In this paper, we present an approach to create interactive views of 4D city models, i.e., 3D spatial models that show changes over time, to provide a better understanding of the urban building situation regarding the photographer’s position and surroundings. A major feature of the application is to make it possible to spatially align 3D reconstruction models to photogrammetric digitized models based on historical photographs. At the same time, this mixed methods approach is used for validation of the 3D reconstructions.