The purpose of computer vision is to make computers capable of
understanding environments from visual information. Computer vision has
been an interesting theme in the field of artificial intelligence. It
involves a variety of intelligent information processing: both pattern
processing for extraction of meaningful symbols from visual information
and symbol processing for determining what the symbols represent. The
term "3D computer vision" is used if visual information has to be
interpreted as three-dimensional scenes. 3D computer vision is more
challenging because objects are seen from limited directions and some
objects are occluded by others. In 1980, the author wrote a book
"Computer Vision" in Japanese to introduce an interesting new approach
to visual information processing developed so far. Since then computer
vision has made remarkable progress: various rangefinders have become
available, new methods have been developed to obtain 3D informa- tion,
knowledge representation frameworks have been proposed, geometric models
which were developed in CAD/CAM have been used for computer vision, and
so on. The progress in computer vision technology has made it possible
to understand more complex 3 D scenes. There is an increasing demand for
3D computer vision. In factories, for example, automatic assembly and
inspection can be realized with fewer con- straints than conventional
ones which employ two-dimensional computer vision.