Abstract :
Digital 3D imaging can benefit from
advances in VLSI technology in order to accelerate its deployment in many
fields like visual communication and industrial automation. High-resolution 3D
images can be acquired using laser-based vision systems. With this approach,
the 3D information becomes relatively insensitive to background illumination and surface
texture. Complete images of visible surfaces that are rather featureless to the
human eye or a video camera can be generated. Intelligent digitizers will be
capable of measuring accurately and simultaneously colour and 3D.
COLOUR 3D IMAGING TECHNOLOGY
Machine vision involves the analysis of the properties of the
luminous flux reflected or radiated by objects. To recover the geometrical
structures of these objects, either to recognize or to measure their dimension,
two basic vision strategies are available.
Passive vision, attempts to analyze the structure of the scene
under ambient light. Stereoscopic vision is a passive optical technique. The
basic idea is that two or more digital images are taken from known locations.
The images are then processed to find the correlations between them. As soon as matching points are
identified, the geometry can be computed.
Active vision attempts to reduce the
ambiguity of scene analysis by structuring the way in which images are formed.
Sensors that capitalize on active vision can resolve most of the ambiguities found with
two-dimensional imaging systems. Lidar based or triangulation based laser range
cameras are examples of active vision technique. One digital 3D imaging system
based on optical triangulation were developed and demonstrated.
ADVANTAGE
Triangulation is the most precise
method of 3D
LIMITATION
Increasing the accuracy increases the
triangulation distance.
The larger the triangulation distance,
the more shadows appear on the scanning object and the scanning head must be made larger.
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