Decoding method and decoding processing device
US9262665B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 2011 |
| Grant date | Feb 16, 2016 |
| Priority date | — |
| Expiry date | Jul 29, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/1486
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a decoding method, photoelectric conversion is performed on light reflected by a code image, a read signal indicating intensity of the reflected light is produced, and the produced read signal is differentiated to produce a derivative signal. The inflection points of intensity of the reflected light in the read signal are detected from the derivative signal and peak levels, each of which is an extreme value of the intensity of the reflected light, the peak level corresponding to a width between the detected inflection points, are detected. A difference between the detected peak levels is then obtained and threshold values for decoding the read signal are set from the obtained difference. This enables the read signal to be decoded even when the code image is spotted with a stain or its printing quality is inferior or even when the read signal is read in its defocus state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.