SketchMapia: A Framework for Collaborative Mapping

• Applicant: Professorin Dr. Angela Schwering
• Subject Area: Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography
• Term: from 2011 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 190786928

With the advent of Volunteered Geographic Information (VGI) emerged the need for new mechanisms for human computer interaction. The SketchMapia project uses sketch maps as the medium for interaction, because laymen can easily express their spatial knowledge in sketch maps without relying on cartographic or technological expertise. Unlike geodetic surveys and metric maps, information from sketch maps is distorted, schematized, incomplete, and generalized. Thus, automatic interpretation of spatial information from sketch maps is not straight-forward.In the first funding period, the SketchMapia project developed the necessary theories for a system that takes freehand sketch maps as input and represents them qualitatively such that spatial information depicted in sketch maps can be aligned to metric maps. We identified seven sketch aspects, which are not affected by cognitive distortions, thus are reliable to be used for alignment. For each sketch aspect we proposed a suitable qualitative representation and compared different approaches to determine alignments. We implemented a prototype as proof of concept that computes qualitative representations of spatial configurations in both, sketch and metric maps, and tested it on sketch maps from our empirical studies: The successful alignment of spatial objects helps to integrate information from sketch and metric maps into one data repository, which can be queried via a query-by-sketch interface.While SketchMapia`s current design incorporates components that deal with cognitive effects such as distortion and schematization, several challenges stand in the way of a successful implementation of the entire workflow from digitizing sketch maps to aligning sketched information to metric maps. These will be addressed by four objectives in the second project phase:OBJECTIVE 1: The lack of a general method for reasoning across different levels of spatial aggregation makes it impossible to align maps at different levels of detail or completeness. The first objective is to devise a method for detecting entities in sketch maps that must be aligned with an aggregation of entities in the metric map.OBJECTIVE 2: The fact that SketchMapia currently processes each sketch aspect separately implies that it is impossible to determine the consistency of an alignment until all alignments of all aspects are complete. The second objective aims to increase performance by identifying concurrently corresponding objects across different sketch aspects.OBJECTIVE 3: The effectiveness of aligning maps by aligning qualitative representations can be improved by employing heuristics based on spatial and non-spatial information. The third objective is to reduce the average time to compute an alignment through a set of heuristics together with algorithms to achieve alignment of spatial aggregates.OBJECTIVE 4 aims to extend the existing prototype implementation to provide a proof of concept of the overall SketchMapia workflow.

• DFG Programme: Research Grants