Method for detecting optical defects in transparencies
US8644587B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 2012 |
| Grant date | Feb 4, 2014 |
| Priority date | — |
| Expiry date | Dec 15, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/30108
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method of detecting optical defects in a transparency may comprise the steps of providing a digital image of the transparency having a plurality of image pixels and detecting at least one candidate defect. The candidate defect may be detected by determining a grayscale intensity of each one of the image pixels and calculating an intensity gradient across adjacent pairs of the image pixels. Each image pixel may be assigned a gradient value comprising a maximum of the absolute value of the intensity gradients associated with the image pixel. A gradient image may be constructed comprising the gradient values assigned to corresponding ones of the image pixels. Image pixels may be identified as candidate pixels if such image pixels have a gradient value exceeding a gradient threshold. The candidate pixels may comprise the optical defect.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.