From European Research Headlines - 24 November 2004
EU project takes digital imaging to new heights
Science has long been at the core of efforts to preserve Europe's valuable and unique cultural heritage. Through advances in digital imaging technology, conservators and restorers are able to capture and keep accurate records of these vestiges of another era. Photographing statues or objects close to the ground is relatively easy but what about ceiling artwork or stained glass windows over ten metres up? EU research has the solution.
Vitra, a project funded under the Commissions IST programme, has built a unique digital imaging system and robotic platform. The 2.6 million project, which builds on previous European research into digital photography and colour image processing, developed a practical method for capturing, storing and viewing high-quality images of architectural details in historic buildings.
Operating safely and efficiently at height is a problem for photographers of culturally significant artefacts. Adjustable tripods and ladders are suitable for heights up to ten metres, but beyond that, scaffold towers are needed which are costly and time-consuming to erect. The Fifth Framework Programme (FP5) Vitra project set out to find an alternative.
According to Lindsay MacDonald, who is a professor of digital media at the University of the Arts London (UK) and the projects coordinator: We designed a robotic carrier to position the camera to sub-millimetre accuracy, with six degrees of freedom, at heights of up to 15m above floor level. This enables photography of everything from stained glass windows and frescos to mosaics and decorative mouldings.
The robotic platform has a pneumatic telescopic mast that carries the camera and artificial lighting. Much like crane operators on building sites, human operators can control the system remotely from below, steering the camera, zooming, panning, as well as managing other settings, such as preview functions, data storage, etc.
Through an man-machine interface, the operator collects real-time information on the whole systems status, including the camera position in the building, which helps image archivists and those carrying out the actual conservation work at a later stage. Systems and equipment were also designed or adapted by the British, German and French partners in the project. For example, software algorithms were designed to do colour matching, so that any reproduction of mosaics and other delicate works of art is faithful to the original.
Other algorithms developed during the 30-month project enable the stitching together of multiple images, or the removal of unwanted shadows from photos of stained glass windows. According to IST Results, the stitching tool will soon be sold as a plug-in for a well-known image processing software. The four partners in the project, which concluded in August, also came up with ways to improve image database systems and a new viewer for panoramic images using Java-3D and JPEG2000 software.
Testing the system in real-world situations and consulting stakeholders in the cultural heritage field was an important aspect of the project. Our system took hundreds of images during trials at five evaluation sites, four in Germany and at a World Heritage Site church in England, says MacDonald. Results indicate that our captured images are of real worth to those who care for and restore such sites.
VITRA is an international partnership from four European countries, led by the Colour & Imaging Institute (CII) at the University of Derby, UK The other full partners are:
University of Derby (UK)
System Simulation (UK)
Bavarian State Department for Monument Restoration (D)
The additional subcontractors are:
English Heritage (UK)
Univerista' di Padova (ITA)
CCD Videomatrie (D)
Wavecrest Systems (UK)