IMODELASER – Integration of image and laserscan data for 3D modeling

In recent years a number of data acquisition techniques have been developed, which are of great relevance for cultural heritage. Several techniques for processing the primary data have been developed in photogrammetry and computer vision as well. These automated processing techniques have reached a level of performance, which is difficult to improve any further substantially. However, in terms of quality and reliability, the results are often not yet acceptable for cultural heritage professionals. To solve this dilemma, the team of professor Armin Gruen (ETH Zuerich) will work on the integration of image and laserscan data for 3D modeling.

Gruen and his team have a strong history of successful projects in cultural heritage. In the context of this work many data processing methods and the related software have been developed, which form the basis of this new project, called IMODELASER. “Recently we have turned our attention also to the processing of laser scan data and panoramic camera data. Over an Inka settlement in Pinchango Alto, Peru we have produced a large high-resolution surface model with 57 terrestrial laserscans and integrated image data. In addition we are processing aerial still video images, acquired with a digital camera from a model helicopter. The first experiences with these techniques, including the use of commercial and own software, allow us very well to pinpoint the problems where substantial additional research is requested in order to make full and appropriate use of those sensors.”

The integration of different kinds of data will facilitate and ease automated processing, professor Gruen strongly believes. “We propose to use laser scanners and imaging devices in an integrated fashion. Laser scanners generate very dense 3D point clouds, which are a good basis for the geometric description of the object. However, lasers scanning provides insufficient information about edges, which ares very important for the modeling of a great majority of CH objects. Digital images, on the other hand, provide excellent information on edges. Therefore both sensors laser scanners and high-resolution cameras are complementary. From their integrated use we expect significant improvements of the quality and speed of automated 3D modeling.”

Gruen plans to do integration on both the sensor level and the data level. Laser scanners come in a great variety of types and products, providing for the possibilities to scan from very close-range (e.g. fragments and other excavation artifacts) up to objects at very large distances (up to several hundred meters).Some laser scanners do have already digital cameras integrated.


As a case study the results of the IMODELASER project will be applied to a Byzantine basilica in Greece, the Church of Panaghia Kera. A model helicopter will be used for acquiring aerial images of the roof structure and the surrounding terrain. The model will consist of both geometry and texture and be visualized in a low-resolution mode for Internet use and a highresolution mode for CD/DVD-based presentations. The showcase should clearly emphasize what makes the integrated approach superior to the single sensor approaches.


Eidgenoessische Technische Hochschule Zuerich