From High Precision Color 3D Scanning of Cultural Artifacts to its Secure Delivery Over the WEB: A Continuum of Technology for the Preservation and Delivery of Cultural Heritage

The delivery of cultural heritage using web-accessible formats has been a limited success. The amount of information that can be displayed using standard web technologies remains limited to a disjointed set of text, images, short movie clips, Quick Time VR, and more recently, small 3D worlds and models represented in VRML format. What is really needed is a new technology that will be able to deliver heritage content into a more compelling storytelling form that is as rich as cinema but without its limitations of linear narrative and its inability to interact with its content. This paper presents some solutions to those issues by considering the continuum of technology necessary to deal with the creation, management, and delivery of cultural heritage content. • Development of secure client/server technology that can deliver interactive complex 3D worlds on low-end machines using compressed image-based technology such as SGI’s VizServer; • Development of large rendering servers capable of producing high quality images for each participant from 3D virtual model securely located at the server site; • Development of a high bandwidth, low latency network capable of delivering the rendered images to the end user; • Evaluation of various system parameters such as compression rate, network bandwidth and latencies and rendering quality on the quality of experience for the end user. All of these technologies exist as separate components. It takes significant technical effort and skill to deploy them in context. An important objective of this project is to demonstrate mew ways of combining such technologies so that they can be effectively used for collecting, accessing and interpreting cultural heritage online. One can see in Figure 1 a block diagram of the system under construction. In Section 2, we will describe how high-dimensional resolution (50 micron) and color resolution models can be created using a combination of off-the-shelf equipment. In Section 3, we will describe the current infrastructure capable of creating and managing large repository of cultural information. We will then describe a prototype system allowing curator and historian to tell stories about this cultural heritage. In Section 4, we will describe the current activities in the delivery of this content. We will describe a new architecture for web delivery that is adaptable to the network capabilities and guaranty the secure delivering of large content to a large public. 2 DEVELOPMENT OF A PORTABLE 3D AND COLOR DIGITIZING STATION For cultural heritage applications, systems that are capable of digitizing artifacts rapidly and safely are still under investigation in many laboratories and cultural institutions around the world. An excellent review of the current state-of-the-art of these digitizing systems can be found in Blais (2004). The problems with digitizing cultural artifacts are that their shapes and material properties are usually very complex making the digitizing process very difficult. Some of the problems associated to the digitizing of these artifacts include: • Objects have a wide dynamic range of surface reflectivity ranging from specular, to transparent, to truly dark matt surface; • Objects have occlusions and cavities; • Objects have large variations of surface roughness ranging from fine detail structures to rough chisel marks; • Objects are not only rigid but also soft and articulated; • Objects have imported information not only in the visible spectrum. Figure 1: Block diagram of the system under development