Virtual Projection Planes for the Visual Comparison of Photogrammetric 3D Reconstructions with Photo Footage

ABSTRACT Image-based 3D reconstructions and their visualization in virtual reality promise novel opportunities to explore and analyze 3D reconstructions of real objects, buildings and places. However, the faithfulness of the presented data is not always obvious and, in most cases, a 3D reconstruction cannot be compared directly to its corresponding real world instance. However, in case of reconstruction methods based on structure from motion (SFM), a large number of raw photos is available. This motivated us to develop a novel interaction technique for the visual comparison of details of 3D models with projections of the corresponding image sections, e.g. in order to rapidly verify the authenticity of perceived features. The results of a formal user study (n=18) demonstrate the general usability of such visual provenance information as well as benefits of the comparison in vicinity of the features in question over a separate image gallery. Further observations informed our iterative design process and led to the development of an improved interactive visualization. Our final implementation provides a spatial and content-related overview while retaining the efficiency of the original approach.