Description
Terrestrial Laserscanning (TLS) is a means of measuring large structures like buildings or archaeological excavation sites. The result of a laserscan is a point cloud, that is a set of 3D coordinates representing the surfaces of scanned objects. When a camera is used, photographs of the scanned objects can be taken, and the photos can be projected onto the scanned points, which results in a colorized point cloud. In the picture above you see a colorized scan of one span of the Stephansdom. This is just an example to show that large structures or buildings are scanned during a scan campaign. During a scan campaign several hundred scans are taken, which are later brought together to form a contiguous model.
Task
| The preprocessing of point clouds is necessary to define the parts of the scans that actually contribute to the contiguous model. For this a clipping volume is applied to a single scan, and only points within the clipping volume are used as part of the model. Other topics related to preprocessing are reading points from different scanner file formats, since each scanner manufacturer uses its own proprietary file format. |
