Here is a list of my publications.


  • Mosaic drawings and cartograms
    R. G. Cano, K. Buchin, T. Castermans, A. Pieterse, W. Sonke and B. Speckmann
    Computer Graphics Forum, 34(3), 2015
    (Proc. Eurographics / VGTC Conference on Visualization (EuroVis) 2015)

    Cartograms visualize quantitative data about a set of regions such as countries or states. There are several different types of cartograms and – for some – algorithms to automatically construct them exist. We focus on mosaic cartograms: cartograms that use multiples of simple tiles – usually squares or hexagons – to represent regions. Mosaic cartograms communicate well data that consist of, or can be cast into, small integer units (for example, electorial college votes). In addition, they allow users to accurately compare regions and can often maintain a (schematized) version of the input regions' shapes. We propose the first fully automated method to construct mosaic cartograms. To do so, we first introduce mosaic drawings of triangulated planar graphs. We then show how to modify mosaic drawings into mosaic cartograms with low cartographic error while maintaining correct adjacencies between regions. We validate our approach experimentally and compare to other cartogram methods.

Formally refereed conference proceedings

  • Mapping polygons to the grid with small Hausdorff and Fréchet distance (in preparation)
    Q. W. Bouts, I. Kostitsyna, M. van Kreveld, W. Meulemans, W. Sonke, K. Verbeek
    Proc. 24nd European Symposium on Algorithms (ESA), 2016

    We show how to represent a simple polygon P by a grid (pixel-based) polygon Q that is simple and whose Hausdorff or Fréchet distance to P is small. For any simple polygon P, a grid polygon exists with constant Hausdorff distance between their boundaries and their interiors. Moreover, we show that with a realistic input assumption we can also realize constant Fréchet distance between the boundaries. We present algorithms accompanying these constructions, heuristics to improve their output while keeping the distance bounds, and experiments to assess the output.

Weakly refereed conference proceedings