Statistical Image Object Recognition using Mixture Densities

  • Authors:
  • Jörg Dahmen;Daniel Keysers;Hermann Ney;Mark Oliver Güld

  • Affiliations:
  • Lehrstuhl für Informatik VI, Computer Science Department, RWTH Aachen, University of Technology, D-52056 Aachen, Germany. dahmen@informatik.rwth-aachen.de;Lehrstuhl für Informatik VI, Computer Science Department, RWTH Aachen, University of Technology, D-52056 Aachen, Germany. keysers@informatik.rwth-aachen.de;Lehrstuhl für Informatik VI, Computer Science Department, RWTH Aachen, University of Technology, D-52056 Aachen, Germany. ney@informatik.rwth-aachen.de;Lehrstuhl für Informatik VI, Computer Science Department, RWTH Aachen, University of Technology, D-52056 Aachen, Germany. gueld@i6.informatik.rwth-aachen.de

  • Venue:
  • Journal of Mathematical Imaging and Vision
  • Year:
  • 2001

Quantified Score

Hi-index 0.01

Visualization

Abstract

In this paper, we present a mixture density based approach to invariant image object recognition. To allow for a reliable estimation of the mixture parameters, the dimensionality of the feature space is optionally reduced by applying a robust variant of linear discriminant analysis. Invariance to affine transformations is achieved by incorporating invariant distance measures such as tangent distance. We propose an approach to estimating covariance matrices with respect to image variabilities as well as a new approach to combined classification, called the virtual test sample method. Application of the proposed classifier to the well known US Postal Service handwritten digits recognition task (USPS) yields an excellent error rate of 2.2%. We also propose a simple, but effective approach to compensate for local image transformations, which significantly increases the performance of tangent distance on a database of 1,617 medical radiographs taken from clinical daily routine.