Development of Web Processing Services for the automated generalisation of isolated polygon groups (WPS-PolyGen)

• Applicant: Professor Dr.-Ing. Dirk Burghardt
• Subject Area: Geodesy, Photogrammetry, Remote Sensing, Geoinformatics, Cartography
• Term: from 2014 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 262049838

The production of topographic and thematic maps for paper and web presentations are based increasingly on automated procedures. They are supported by manual, interactive pre-and post-processing depending on the application and quality requirements. The aim of the proposed project is to develop automated generalisation procedures further, in particular approaches for processing grouped cartographic objects. Necessary therefore is the consideration of structural relations, which is the generalisation task with the greatest complexity as mentioned by Bertin (1974).First approaches that overcome an isolated generalisation of single objects exist for the aggregation within polygon mosaics, for the thinning of roads and water networks as well as for the generalisation of building groups. Advanced research and development is required for the derivation of cartographic representations of isolated polygon groups which stand for natural objects such as lakes, islands and forests.In the proposed project, the following main tasks has to be processed. First, techniques must be developed for the partitioning and conflict detection using spatial index structures such as the R-tree. In the second step, the design and development of generalisation algorithms has to be carried out for isolated polygon groups with focus on the typification. Starting point can be the utilisation of hierarchical, agglomerative and graph-based clustering methods. The aim is to develop an iterative method, which generates characteristic representations in consideration of scale respective resolution with increasing distance and size thresholds. The third main task is on the modelling and consideration of structural relationships between polygons in the generalisation process. For this purpose, enriched data structures can be introduced implemented as horizontal relational objects and additional cartographic constraints has to be defined to maintain respective homogenise the group properties.Complementary to the above mentioned tasks the projects aims on the implementation of further generalisation operators for isolated polygon groups as Web Processing Service. Research questions will deal with the orchestration and combination of the generalisation operators which have been developed for individual and group objects. The still predominant isolated generalisation of individual objects could be overcome. A new qualitative level can be achieved in the automated map production through the development of approaches for modelling relations in terms of data enrichment and a consideration of the structural relationships by generalisation operators. Refined generalisation web services would help to reduce manual processing and to increase the actuality of maps.

• DFG Programme: Research Grants