Pattern collation apparatus based on spatial frequency characteristics
US5915034A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 1996 |
| Grant date | Jun 22, 1999 |
| Priority date | — |
| Expiry date | Apr 26, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V40/1376
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a pattern processing apparatus, a registration data preparation unit performs two-dimensional discrete Fourier transform of image data of a registration pattern to prepare registration Fourier image data. A collation data preparation unit performs two-dimensional discrete Fourier transform of image data of a collation pattern to prepare collation Fourier image data. A data synthesizing unit synthesizes the registration Fourier image data with the collation Fourier image data, both of which consist of phase and amplitude information, to output first synthesized Fourier image data. An image processing unit performs Fourier transform of the first synthesized Fourier image data to output second synthesized Fourier image data representing intensities of correlation components. A pattern collation unit collates the registration pattern with the collation pattern on the basis of the intensities of the correlation components of pixels in a correlation component area set in the second synthesized Fourier image data. An amplitude suppressing processing unit performs amplitude suppressing processing of one of the registration/collation Fourier image data and the first synthesized Fourier i…
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