Monday, May 10, 2010

3D Scanning as Dense Microphone Array

Sound is the displacement of matter over time.

A microphone detects sound at a single point, either via direct physical coupling, or using optical methods (as with Laser microphones).

3D scanning can also detect displacement of reflective matter over time. Using a 3D scanning setup with a very large angle between the camera and projector, very minor displacement variations can be detected. Using a high framerate camera, this displacement can be measured at audio frequencies. Every pixel then corresponds to a virtual laser microphone: instead of the usual microphone at a point, a fringe analysis microphone is comprised of N points as determined by the camera resolution.

1 comment:

Thomas said...

The sampling rate is the problem here... need to scan at above 20kHz, which is hard enough with a laser pointing at a single spot.