3D-IPTV: Single camera 3D Intensity Particle Tracking Velocimetry using particle intensities and structured light.*

A single camera and a consumer grade LCD projector is used to achieve 3D Intensity Particle Tracking Velocimetry (3D-IPTV). This is possible using a structured monochromatic illumination sequence from the projector perpendicular to a camera. The 2D motion projection of the particles is recorded with the video camera. We encode the depth position of each particle (perpendicular to the image plane of the camera) in their intensity relative to their intrinsic brightness, to obtain full 3D paths.  A 3D laser engraved glass cube with 1100 known spatial distribution defects is used for calibration. The calibration process includes the light-intensity field calibration and spatial distortion corrections from the projected light divergence and optical walls. Using a combination of changing light patterns and multiple sub-gradients of intensity, we can achieve 200 depth levels of resolution in a volume of approximately 60 x 60 x 50 mm³.