Gabor Filter

  Gabor filters are defined by harmonic functions modulated by a Gaussian distribution. As an example, in two dimensions and using a polar coordinate system with coordinates and :

Gabor filters bear some similarity to Fourier filters, but (by the Gaussian damping terms) are limited to certain frequency bands (``passband filter''). With a judicious choice of frequencies, e.g. by octaves (viz. by successive factors of 2), a succession of Gabor filters can be assimilated to a wavelet transform, and do an excellent job in image or information compaction. Compare also Haar Transform.