Comparison in the Hausdorff Metric of Reconstruction of 3D Urban Terrain by Four Procedures

We computationally compare four procedures, namely, alpha-shapes, iso-surface extraction, gridfit and L1 splines for geometric reconstruction of 3D urban structures represented by irregular point clouds with abrupt changes in density. For significant numbers of outliers, L1 splines produce the most accurate reconstructions both visually and when measured analytically in the Hausdorff metric but are more computationally expensive than the other three procedures.