A. Moya et al., Shift- and scale-invariant recognition of contour objects with logarithmicradial harmonic filters, APPL OPTICS, 39(29), 2000, pp. 5347-5352
The phase-only logarithmic radial harmonic (LRH) filter has been shown to b
e suitable for scale-invariant block object recognition. However, an import
ant set of objects is the collection of contour functions that results from
a digital edge extraction of the original block objects. Therefore, since
the energy of the contour objects decreases more slowly with the scale fact
or than does the energy of the block objects, the phase-only LRH filter has
difficulties in the recognition tasks when these contour objects are used.
We propose a modified LRH filter that permits the realization of a shift-
and scale-invariant optical recognition of contour;objects. The modified LR
H filter is a complex filter that compensates the energy variation resultin
g from the scaling of contour objects. Optical results validate the theory
and show the utility of the newly proposed method. (C) 2000 Optical Society
of America. OCIS code: 100.5010.