Accession Number : ADA295615

Title :   Recognizing 3D Object Using Photometric Invariant.

Descriptive Note : Memorandum rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE ARTIFICIAL INTELLIGENCE LAB

Personal Author(s) : Nagao, Kenji ; Grimson, Eric

PDF Url : ADA295615

Report Date : FEB 1995

Pagination or Media Count : 23

Abstract : In this paper we describe a new efficient algorithm for recognizing 3D objects by combining photometric and geometric invariants. Some photometric properties are derived, that are invariant to the changes of illumination and to relative object motion with respect to the camera and/or the lighting source in 3D space. We argue that conventional color constancy algorithms can not be used in the recognition of 3D objects. Further we show recognition does not require a full constancy of colors, rather, it only needs something that remains unchanged under the varying light conditions and poses of the objects. Combining the derived color invariants and the spatial constraints on the object surfaces, we identify corresponding positions in the model and the data space coordinates, using centroid invariance of corresponding groups of feature positions. Tests are given to show the stabillty and efficiency of our approach to 3D object recognition.

Descriptors :   *ALGORITHMS, *OPTICAL IMAGES, *PHOTOMETRY, SOURCES, METHODOLOGY, CENTER OF GRAVITY, COMPUTATIONS, LIGHT, MOTION, EFFICIENCY, ILLUMINATION, PROBLEM SOLVING, SURFACES, THREE DIMENSIONAL, COLORS, GEOMETRY, LIGHTING EQUIPMENT, INVARIANCE.

Subject Categories : Cybernetics
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE