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USING OF LASER AND DIGITAL CAMERA BASED SYSTEMS 
FOR 3D OBJECT DOCUMENTATION 
K.Pavelka 
Czech Technical University in Prague, Faculty of Civil Engineering, Dept. Mapping and Cartography, 
Laboratory of Photogrammetry, Thäkurova 7, 166 09, Prague 6, Czech Republic 
Tel.:+42024354951, Fax:+42024310774, E-mail: pavelka@fsv.cvut.cz 
Commission CIPA, WG 6 
KEY WORDS: digital photogrammetry, 3D documentation, laser scanning 
ABSTRACT: 
Examples of systems based on simple digital camera and laser are discussed in the paper. At the Czech Technical University in 
Prague, photogrammetric measurement is performed in the Laboratory of Photogrammetry (Faculty of Civil Engineering). Based on 
a grant of the Czech Grant Agency, a large project on historical monument documentation and presentation by using a new digital 
technology has been started. In the framework of co-operation between the Laboratory of Photogrammetry and the Laboratory of 
Quantitative Methods of Monuments Research (Faculty of Nuclear Physics and Physical Engineering), new methods of 3D objects 
documentation as a part of project are tested. Two devices for 3D object co-ordinates capturing are being developed at present. The 
first device uses a rotating platform developed for small objects, a laser for point or profile marking (on the object) and a digital 
camera (for image sequence saving) on theodolite. Such a 3D scanner can be used for small compact objects, such as small 
sculptures, vessels, models and so on. The second device uses rotating stabile base equipped with a digital camera and a laser for 
point marking. This type is suitable for profiling of tunnels for example. The expected outputs are not only the 3D co-ordinates of 
the object, but also the experience with a new technology based on using laser and automatic image processing. 
1. NEW DEVICES FOR 3D OBJECT MEASURING 
In the framework of co-operation between the Laboratory of 
Photogrammetry and the Laboratory of Quantitative Methods of 
Monuments Research (Faculty of Nuclear Physics and Physical 
Engineering), new methods of 3D objects documentation as a 
part of project are tested. Two devices for 3D object co 
ordinates capturing are being developed at present. The aim of 
the project is to develop a small inexpensive device for special 
purposes of 3D documentation. By combining several electronic 
parts such as CCD camera, laser marker, computer and distance 
measuring device a new laser sensor has been developed. There 
are only few possibilities how to construct laser based 3D 
sensors. The principle of these devices is the same: the laser 
beam is used as an object point marker (single point or line on 
object) and the laser track is recorded by using of a small CCD 
camera. The camera and laser position are convergent to the 
object, 3D co-ordinates can be computed from laser-camera 
basis. 
2. LASER SYSTEM WITH ROTATING PLATFORM 
For small objects such as small sculptures, vessels or models a 
system with rotating platform has been constructed. A laser 
beam optically modified to a thin line on the object is recorded 
from a basis with CCD camera. A maximum of 25 frames per 
second can be used. The measured object is situated on a 
rotating platform with a possibility to change the rotating 
velocity. All the images are stored on a PC and processed by 
using of special software. From the image coordinates of 
marked object points the real 3D coordinates are computed. The 
scanning process is demonstrated on Fig. 1. 
i 
Fig. 1 : Rotating platform system