StudiesOpen Theses
Registrierung von Punktwolken mittels Segmenten

Registration of point clouds using segments

Email:  florian.politz@ikg.uni-hannover.de
Team:  Politz, Brenner
Year:  2019

Introduction and goals of this thesis

For their territory, national survey departments have extensive Airborne Laser Scanning (ALS) point clouds with moderate point densities, and a high position and height accuracy. The national survey departments also derive point clouds from aerial flight operations using an algorithm called Dense Image Matching (DIM). These point clouds have a high geometrical and radiometric resolution. For change detection between different points in time as well as for updating the official digital terrain and digital surface models, the correct registration of different point clouds is a crucial part in the processing chain.

The goal of this thesis is to develop different methods, which should register point clouds using segments. The registration on 2D- as well as on 3D-level should be investigated.

Tasks

1.    Introduction into the point cloud data, algorithms and relevant literature

2.    Registration of the point clouds on 2D-level

a.    Transformation of the 3D point clouds into 2D raster images considering normal vectors and deviation from a local plane

b.    Segmentation of the raster images using the graph-based approach of Felzenszwalb and Huttenlocher (2004)

c.    Registration of those raster images in X and Y direction using correlation and in Z direction using Maximum Consensus estimation (in 3D)

3.    Registration of the point clouds on 3D-level

a.    Segmentation of the point clouds using RANSAC considering normal vectors and deviation from a local plane

b.    Alignment of the registration parameters using the segmented 3D planes

4.    Quantitative and qualitative comparison of both registration methods

5.    Documentation and presentation of the results

Requirements

Programming knowledge in Python desirable

Contact

Florian Politz (e-mail florian.politz@ikg.uni-hannover.de, phone: 0511 762-19436)

apl. Prof. Dr.-Ing. Claus Brenner (e-mail claus.brenner@ikg.uni-hannover.de, phone: 0511 762-5076)

 

Institut of Cartography and Geoinformatics, Appelstraße 9a, 30167 Hannover, room 616