Automatic mask threshold
US5261010A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 1991 |
| Grant date | Nov 9, 1993 |
| Priority date | — |
| Expiry date | Sep 27, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06V10/28
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An improved method for finding the mask threshold for a maskable bilevel correlator operates on a series of frames of information. Beginning with an initial threshold, two rates are computed. The rate of change of the correlation peak magnitude P.sub.(T), a function of threshold T, with respect to the change in the value of the mask threshold T, or (dP.sub.(T) /dT), and the corresponding rate of change of correlation reference pixels with magnitude exceeding the mask threshold, U.sub.(T), a function of threshold T, with respect to the change in the value of the mask threshold T, or (dU.sub.(T) /dT), are measured. The correct, or best, value of the threshold occurs when .vertline.dP.sub.(T) /dT.vertline..gtoreq.0.5*.vertline.dU.sub.(T) /dT.vertline..
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.