Automatic processing of Terrestrial Laser Scanning data of building façades

Feature extraction on façades from unstructured point clouds is a challenging work, especially in the presence of noise. Point cloud segmentation is one of the most important steps in this context. In this paper, a new approach for automatic processing of façade laser scanner data is introduced. Scanner orientation is partially known through the inclination sensors of the laser scanner used. Knowing these values allows us to reduce the point cloud data into a profile distribution function. After orientation, this distribution is a series of peaks and valleys suitable for segmentation. Each segmented layer is afterwards processed to find the façade contours. The results obtained prove that the approach may be successfully employed in building segmentation and extraction of planar features. Moreover, the accuracy of contours is very dependent on the resolution of the scan data.

► We scan a facade with a TOF terrestrial laser scanner with different point spacing.
► We know the orientation through inclination sensors and a profile distribution.
► We use the distribution for segmentation finding local maxima and minima.
► We process each segmented layer to find the contours of the façade.
► We use the contours to make measurements in the façade.