SMARTER STRATEGIES

3D Modeling Automated by MEMS Pico-Projectors

R. Colin Johnson | Date: 08-25-10 | Comments

3D models, which usually require tedious manual measurements, can now be automatically created from real-life scenes using structured light illumination (SLI) technology with micro-electro-mechanical system (MEMS) pico-projectors. The algorithms for applications from video gaming to medical diagnosis are being pioneered at the Center for Visualization and Virtual Environments at the University of Kentucky and commercialized by Seikowave (Lexington, Kentucky).

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3D Modeling Automated by MEMS Pico-Projectors - Detailed 3D Models

PneumaCare automatically generates a 3D model of the chest of a lung patient in real-time for medical diagnosis.

To allow SLI to be used in areas already illuminated by visible light, Seikowave is working with MEMS chip makers to create an infrared pico-projector that uses invisible illumination. Outfitted with invisible infrared light patterns�similar to the invisible IR emitted by remote controls�this technology could allow systems to work unobtrusively. For instance, sensors could surreptitiously scan the fingerprints of people as they enter sensitive areas to ensure unauthorized personnel are not slipping by traditional security systems.

Two pitfalls of the technique are the high illumination levels and the high scan rates required, compared to traditional pico-projectors. In essence, the brighter and faster the patterns can be scanned onto objects, the faster the 3D model-building algorithms can run. For real-time creation of 3D models, scan rates need to be faster than 250 frames per second, and illuminations levels must be in the hundreds of lumens�both beyond the reach of off-the-shelf DLP pico-projectors. Even the newest commercial pico-projector technologies, such as the liquid crystal on silicon (LCoS) technology from 3M and laser-based units from Microvision, are too dim and slow for commercial structured light illumination.

To remedy these setbacks, Seikowave is currently courting makers of less-well-known optical projection technologies, such as the grating light valve (GLV) technology from Silicon Light Machines (Sunnyvale, Calif.). GLVs can scan with infrared light at speeds measured in thousands of frames per second, enabling future Seikowave scanners to produce extremely detailed 3D models in real-time.