CESL - Colour Encoded Structured Light
During the period
1991-1994 Tim Monks developed a
parallel structured light scanner capable of digitising moving or changing 3D objects such
as the human face and mouth to millimetre accuracy, and sampled at 50Hz. The technique
used is called "Colour Encoded Structured Light" and was the subject of
Tim's PhD Thesis at the University of
Southampton, where it was used to measure lip, mouth and cheek shape during continuous
speech for acoustics of speech research. 
The scanner operates by projecting a coloured pattern onto the surface to be digitised, which is then viewed by a camera from a slightly altered viewpoint. The distortions in the pattern are detected automatically (the colour coding allowing unique identification of each stripe) and converted into 3D measurements in millimetres, The great advantage of this system is that since each image output by the camera can be used to digitise a 3D view of the subject, moving and changing objects can be digitised at video rates.
Contact Tim Monks for more
on the information on the Colour Encoded Structured Light scanner, or take a look at the abstract from his thesis.
You can also download an Adobe Acrobat PDF document containing the full thesis (2.2MBytes).
Third Dimension's MTS is the next generation of CESL, with increased depth of field, accuracy and industry strength robustness.