Neural Information Processing - Letters and Reviews

Vol. 10, No.12, December 2007

pp. 247-255

Fast Density Codes for Image Data

Pierre Courrieu
Laboratoire de Psychologie Cognitive, UMR CNRS 6146, Université de Provence – Centre St Charles
Bat. 9, Case D, 3 place Victor Hugo, 13331 Marseille cedex 3, France


Recently, a new method for encoding data sets in the form of "Density Codes" was proposed in the literature (Courrieu, 2006). This method allows to compare sets of points belonging to every multidimensional space, and to build shape spaces invariant to a wide variety of affine and non-affine transformations. However, this general method does not take advantage of the special properties of image data, resulting in a quite slow encoding process that makes this tool practically unusable for processing large image databases with conventional computers. This paper proposes a very simple variant of the density code method that directly works on the image function, which is thousands times faster than the original Parzen window based method, without loss of its useful properties. 

Keywords - Image encoding, shape recognition, invariants, fast computation, neural processing simulation.