Shadow detection from VHR aerial images in urban area by using 3D city models and a decision fusion approach

In VHR(very high resolution) aerial images, shadows indicating height information are valuable for validating or detecting changes on an existing 3D city model. In the paper, we propose a novel and full automatic approach for shadow detection from VHR images. Instead of automatic thresholding, the supervised machine learning approach is...

Automatic shadow detection in urban very-high-resolution images using existing 3D models for free training

Up-to-date 3D city models are needed for many applications. Very-high-resolution (VHR) images with rich geometric and spectral information and a high update rate are increasingly applied for the purpose of updating 3D models. Shadow detection is the primary step for image interpretation, as shadow causes radiometric distortions. In addition,...

LiDAR-guided dense matching for detecting changes and updating of buildings in Airborne LiDAR data

Change detection is essential to keep 3D city models up-to-date. LiDAR data with high accuracy are used to create 3D city models. However, updating LiDAR data at state or nation level often takes around a decade. Very high resolution (VHR) stereo images, with often yearly updating rate and dense 3D information, provide an option for...

Combining LiDAR and Photogrammetry to Generate Up-to-date 3D City Models

3D city models are increasingly used to maintain and improve urban infrastructure. Keeping 3D city models accurate and up-to-date is essential for municipalities to make decisions in a time of strongly increasing urbanization. 3D information provided by airborne laser scanning (ALS) is widely used for generating 3D city models. However, ALS data...