Regularization of building roof boundaries using CD-spline from LiDAR data

Abstract

Building boundaries play an essential role in many applications such as urban monitoring, managing and planning and production of 3D realistic views. In this sense, it is proposed a new methodology for building roof boundary regularization based on the CD-spline (Changeable Degree - Spline) concept. This concept was first explored during the doctorate and allow to model complex boundaries by means of polynomial functions of different degrees for a given building. The results obtained during the doctorate indicated the potentiality of CD-spline in the boundary regularization from LiDAR data obtained by airborne scanning systems. Despite the promising results, some limitations were identified: the result is directly influenced by the corner point identification and by the presence of outliers in the boundary; modeling errors in occlusion regions caused by the presence of vegetation near buildings; and difficulty in identifying and representing small segments. To overcome these problems, a new strategy is proposed, which includes the automatic selection of corner points by means of the residual analysis, outlier identification method and determination of a weight function for the boundary points. The quality evaluation will be carried out through qualitative and quantitative analysis from three dataset of different countries, being highlighted the advantages and limitations of proposed method. It is expected that the new methodology allows the mitigation of the highlighted problems and, consequently, the achievement of more accurate boundaries. (AU)