| Authors |
Meixner Philipp, Leberl Franz |
| Appeared in |
ASPRS (American Society of Photogrammetry and Remote Sensing) Annual Convention, Unpaginated DVD |
| Date |
2010 |
| Abstract |
Accurate and realistic 3-dimensional models of urban environments are increasingly important for applications like virtual tourism, city planning, internet search and many emerging opportunities in the context of “ambient intelligence”. Applications like Bing-Maps or Google Earth are offering virtual models of many major urban areas worldwide. While initially, these data sets support visualization they are inherently capable of addressing a broader purpose. On the horizon are urban models that consist of semantically interpreted objects; an urban 3D visualization will be computer generated, with a fundamental advantage: the urban models can be searched based on object classes.
This paper presents a framework which specifies the processing steps that are necessary for a reasonable semantic interpretation and evaluation of real property using high resolution aerial images.
We first describe the different source data which have to be brought into a common coordinate system. In this process we build an integrated geometry and semantic object data set that can be analyzed for various purposes. Our focus is on characterizing individual properties and to determine the size of buildings, their number of floors, status of vegetation, roof shapes with chimneys and sky lights etc.
We start out by merging the aerial imagery with the cadastral information to define each property as a separate entity for further analysis. The cadastral data may also contain preliminary information about a building footprint.
In the next step the building footprints get refined vis-à-vis the mere cadastral prediction, using an image classification and the definition of roof lines. 3-D façade coordinates are computed from aerial image segments, the cadastral information and the DTM. This helps to determine the number of floors and the window locations to see if there are attics and basement windows.
The paper uses an experimental data set of the City of Graz (Austria) with 216 buildings representing 321 separate properties. We present the results of the characterization with as much information as possible being extracted about each property and related to manually collected ground truth. |
| Link |
PDF |
