Proceedings of the zyxwvutsrqpo 2000 zyxwvutsrqpon IEEE InternationalConference on Robotics zyxwvutsrqpon & Automation San Francisco, CA April 2000 zyxwvutsrqpon Beyond Range Sensing: XYZ-RGB Digitizing and Modeling M. Rioux, F. Blais, A.B. Beraldin, G. Godin, P. Boulanger and M. Greenspan Visual Information Technology Institute for Information Technology National Research Council Canada M-50 Montreal Road, Ottawa, Ontario, Canada, K1A OR6 http://www.vit.iit.nrc.ca/ Abstract zyxwvuts This talk will review the progress and the evolution of the development of range sensing techniques at the NRC laboratories. Essentially a 30 imaging project at the beginning, it has evolved to a new media project which requires the development of new tools for 30 modeling, editing, database searching and visualization. Generic applications related to documentation, inspection, target tracking and visual communication will be discussed. 1 Introduction The surface shape of objects can be imaged and digitized using the following basic components: a light source to define a specific pixel(s), such as an encoding-decoding process (triangulation, fringes and patterns projections and time of flight are examples), a sensing device composed of a collecting lens and a photodetector that convert light energy to an electrical signal, an analog to digital converter and finally a computer to process, display, and store the raw data. Conventional light sources can and are used to digitize shapes, but laser sources have unique advantages for 3D imaging. One of them being its brightness, which cannot be obtained by incoherent emitters. Another feature is the spatial coherence, which allows the laser beam to "stay in focus" when projected onto the scene. Upon scattering, the spatial coherence of the laser light is lost, which means that the depth of field used at the projection can be useful only if we close down the lens aperture at the collection, otherwise the focused laser spot is imaged as a blurred disk of light zyx on the photodetector. A solution to this problem is to modify the conventional imaging geometry to conform to the Scheimpflug condition'. Essentially, this geometry allows the position-sensing detector surface to "stay in focus" with the projected laser light. Figure 1 shows on top the first prototype build in 1982 and an illustration of the scans produced at that time. Most of the design including visualization was based on analog electronics. Below is a photograph of a Virtual Reality theater installed at the Canadian Museum of Civilization located in the Ottawa area. Also a photograph of a multimedia document which is integrating computer graphics, photographs, a 3D scan of a replica of the Tutankamon mask, narration and music. This interactive virtual visit of the Tutankamon tomb has been shown for an Egyptian exhibit which ended spring 1999. Since 1982, the whole process has evolved to digital, from scanning to display. 0-7803-5886-4/00/$1 O.OO@ zyxwvutsr 2000 IEEE 111