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Quality of 3D Building Models Derived from Airborne Laser Scanner

Jalali, Amirpouya (2010) Quality of 3D Building Models Derived from Airborne Laser Scanner.

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Abstract:Nowadays, Three Dimensional (3D) models are used widely in human life in several fields such as architecture, civil engineering, entertainment, medicine and city models. City models are suitable for various applications such as urban planning, vehicle navigations, 3D cadastre and facility managements. 3D building models are one of the main components of city models. Quality of 3D building models is important to judge about their usability in different applications. Different modellers/researchers had used various methods for assessing the quality of their models/reconstruction methods. For assessing quality of 3D models lack of using unique standards and comprehensive quality aspects that can describes quality of models in more aspects still exists. In this thesis, after reviewing various used quality issues, different quality aspects were introduced and described for assessing the quality of 3D building models. In this case, each 3D model was divided into three main parts: Body, roof and dormers. For each part, some related quality aspects were proposed and discussed. Roof similarity and geometry of roofs were presented as quality aspects related to roof parts. Dormer’s reconstruction rate and geometry check of dormers were presented as quality aspects related to dormer’s part and for body part, positional accuracy, footprint correctness and height accuracy were introduced. The main idea was preparing quality report for each set of models by means of assessing the introduced quality aspects. With this quality report, users due to their requirements are able to judge about the usability of reconstruction method, used input dataset and set of 3D models. Moreover, making decision about the correctness of 3D model (or set of models) would be possible by having comparison between prepared quality report and user’s requirements. On the other hand, by evaluating quality of two different sets of 3D models that were reconstructed from ALS (as their input dataset), pros and cons of each of the used reconstruction method were discussed. In this case, 3D building models were reconstructed in both semi-automatic and automatic method by selecting some sample buildings were selected with a defined building selection strategy. Quality aspects of each of the selected building models in both sets were assessed. By assessing all introduced quality aspects for each model individually, quality reports for each set of automatic models and semi-automatic models were prepared. With helps of this quality reports and discussion on quality of each aspect, it was concluded that, shape of footprints, shape of roofs, overhangs in models are crucial components that influence the quality of 3D models. The effects of human interpretations were also observed. Moreover, results of assessed quality aspects of automatic models were compared with quality measures that can automatically be generated from automatic reconstruction method. These comparisons concluded that quality measures that automatically generated in automatic reconstruction method are useful for assessing roof similarity and height accuracy of 3D models. The results of these automatic generated quality measures were correct in roof similarity and accurate in height accuracy of 3D models. Keywords: Airborne Laser Scanner (ALS), Quality assessment, 3D building model, Quality report, Semi-automatic approach.
Item Type:Essay (Master)
Faculty:ITC: Faculty of Geo-information Science and Earth Observation
Programme:Geoinformation Science and Earth Observation MSc (75014)
Link to this item:https://purl.utwente.nl/essays/92481
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