Browse Prior Art Database

Calibration of Active Field of View Based On Expected Part Location

IP.com Disclosure Number: IPCOM000103073D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 1 page(s) / 38K

Publishing Venue

IBM

Related People

Colson, JC: AUTHOR [+2]

Abstract

Disclosed is a software method for distortion compensation when calibrating vision systems. Also, a software method for automatically determining the active field of view of a vision system, based upon CAD descriptions of the part to be viewed, is described.

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Calibration of Active Field of View Based On Expected Part Location

      Disclosed is a software method for distortion compensation when
calibrating vision systems.  Also, a software method for
automatically determining the active field of view of a vision
system, based upon CAD descriptions of the part to be viewed, is
described.

      The locations for calibration are chosen by software evaluation
of the active field of view.  The term "active field of view" means
the actual sub-portion of the field of view where objects are
typically expected to be found.  This may be achieved by user-defined
limits of the expected part location, or by software evaluation of
the size of the part and known tolerances for its positioning, based
upon CAD data.  The locations for calibration are chosen only from
the active field of view sub- portion. The method for choosing points
within the active field of view may be either chosen randomly, or
systematically to cover the active field of view evenly.

      For example, consider the case of component location.
Typically, the field of view is slightly larger than the component
itself.  However, the active field of view consists only of the
subregions in the field of view that have component leads to be
inspected.  In this case, points for calibration should be chosen
only from the subregions used by the system, and not from the entire
field of view.

      Disclosed anonymously.