Benchmarking Image-based DSM Generation - 30/12/2013


In view of the rapid advancement in photogrammetric technology and software for 3D reconstruction, the European Spatial Data Research Organisation (EuroSDR) initiated a benchmark project on image-based generation of digital surface models (DSM). Such a comparative evaluation provides a platform for software developers to demonstrate the potential of their ongoing work.

 
Perspective of the reconstructed Munich dataset, GSD is 10cm.

Furthermore, it can help users like national mapping and cadastral agencies responsible for state-wide generation of high-quality DSMs to understand the applicability of such tools while triggering further developments based on their needs. The comparative results from 10 participants presented here provide comprehensive insight into the landscape of dense matching algorithms and demonstrate the current potential of image-based photogrammetric data collection.

 

To limit the data-processing effort required by potential participants, the test was restricted to subsets of aerial image flights. Thus, two representative datasets consisting of two aerial image sub-blocks with different land cover and block geometry were prepared. The first dataset, Vaihingen/Enz, is representative for data usually collected during state-wide DSM generation in areas with varying land cover. It covers a semi-rural area of undulating terrain. Both ground sampling distance and image overlap are rather moderate. The sub-block selected for the benchmark consists of three strips each with 12 images, resulting in four to nine images per object point.

 

The DSM had to be generated for the block centre measuring 7.5km x 3km. Its pre-defined grid width of 0.2m corresponds to the ground sampling distance (GSD) of the aerial imagery used. The second test dataset is more typical for applications in densely built-up urban areas, where images are usually captured at a higher overlap and resolution. The Munich dataset covers the central part of the city and was captured at a GSD of 10cm with 80% in flight and 80% cross flight overlap. This results in up to 15 folded object points and thus a considerable redundancy. The image sub-block to be processed consists of three image strips each with five images. The area to be processed measures 1.5km x 1.7km. 

Last updated: 18/11/2017