To make preformable a pattern recognition irrelevantly to the direction and size of a pattern by recognizing a pattern obtained by pattern characterization.
In a preprocess step 1, a source image is formed by scanning an original image I, In a step 2, a pattern to be recognized in a threshold- processed image Is is detected. A step 3 is a character imparting step for the pattern F obtained in the step 2, and a invariable descriptor is obtained by using Fourier-Mellin transformation. Denoting MF(p, q) as Fourier-Mellin transformation of a pattern and (p) and (q) as coefficients representing invariables of the pattern corresponding to rotation and scale variation, DF(p, q)=MF(p, q)[MF(0, 1)]-qMF(0, 1)]qMF(0, 0)]p is obtained. A step 4 is a pattern recognition step and the descriptor DF obtained by the Fourier-Mellin transformation is compared with a reference descriptor.
CARIOU CLAUDE
IVIGLIA JOEL
AUGER JEAN-MARC
| JPH09167226A | 1997-06-24 |