REALISTIC 3D RECONSTRUCTION - COMBINING LASERSCAN DATA
WITH RGB COLOR INFORMATION
Abmayr T., Hiirtl F., Mettenleiter M., Heinz L, Hildebrand A., Neumann B., Frohlich C.
Zoller + Frohlich (Z+F) GmbH, Simoniusstr. 22. D-88239 Wangen, Germany
Phone: +49-7522-9308-0; www.zf-laser.com; info@zf-laser.com
KEY WORDS: Architectural Heritage Conservation, Engineering Heritage Conservation, Close Range Photogrammetry and
3D Scanning, Cultural Heritage, Industry, Laser scanning, Terrestrial, Three-dimensional
ABSTRACT:
Laserscanners are used more and more as surveying instruments for various applications. With the advance of high precision
systems, capable of working in most real world environments under a variety of conditions, numerous applications have opened up.
The developed IMAGER 5003 is a state-of-the-art, high precision, high speed laser scanner that provides accurate measurements.
In order to monitor scenes by means of range and reflectance images, the IMAGER 5003 is based on a phase-shift measurement
principle. In combination with a newly developed scanning system, the system provides a wide field of view of 360° (horizontal) x
310? (vertical) with an image resolution of up to 20000 x 20000 pixels within one single image. Scanning time for a full scan
depends on the section to be scanned and the number of measured points — for a standard image 360° x 310°, 10000 x 10000 pixels
less than minutes. The IMAGER 5003 measures both, range and reflectance images at the same time. The range image generates
geometric dimensions of the environmental scenes whereas the reflectance image generates a photographic like impression of the
scanned environment which is used for feature extraction, visual inspection, object segmentation, surface classification and
documentation purposes.
To realise surveying tasks in architectural, archaeological and cultural landscapes conservation, a high resolution line scan camera is
used: The camera was developed by the German Aerospace (DLR) and enables the mapping of 2D RGB color information onto the
3D point cloud of the scanner unit in a simple manner.
This paper introduces into the main features of the Z+F IMAGER 5003 as well as of the DLR line scan camera and explains the way,
how scanner data and RGB image data are combined. It shows results from cultural landscape conservation projects as well as from
industrial applications. Finally it gives an outlook to further work in the laser scanning development area.
1. INTRODUCTION
Reconstructing buildings and scenes in a realistic fashion is a
popular topic in virtual reality projects. Whereas in recent years
the main focus of research concentrated on 3D reconstruction
based on 2D image data, laser scanning technology nowadays
gets more and more popular: Geometric 3D laser scan data is
combined with high resolution and high quality 2D RGB color
camera information. In order to produce three dimensional
geometric measurements with colour information, we use two
systems: the IMAGER 5003 for geometry and reflectance mea-
surements in combination with a high resolution CCD line scan
camera. This paper introduces the main features of these two
systems and shows how RGB color information can be mapped
onto a 3D point cloud. The paper concludes with examples.
2. SYSTEM FEATURES AND DATA ACQUISITION
The first part of this chapter deals with the main features of the
two systems, followed by an overview of the software of both
systems. In the third part it is shown how the information of
both sensors can be combined.
2.1 The IMAGER 5003
SYSTEM FEATURES
The visual laser scanner IMAGER 5003 of Z+F (Figure 1) is an
optical measuring system based on the transmission of laser
light (see [Fró02], [Ste02]. [Hae01 ]. [HeiO1]). The environment
is illuminated on a point by point basis and then the light
reflected by an object is detected. Tbe laser scanner consists of a
one-dimensional measuring system in combination with a
mechanical beam-deflection unit for a spatial survey of the sur-
roundings.
Figure 1: The figure shows the IMAGER 5003
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