Method for robust asymmetric modulation spatial marking with spatial sub-sampling
US7492920B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 19, 2003 |
| Grant date | Feb 17, 2009 |
| Priority date | — |
| Expiry date | Aug 20, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S283/902
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Example embodiments relate to a method for applying a special mark, that is invisible to the naked eye, on a medium. That is, the example embodiments provide a method for generating and applying on a medium a digital spatial mark of X×Y dots in accordance with a resolution of d1x by d1y dots per surface unit, provided that the ratio d1x/d2x and or d1y/d2y is more than 1. The method further includes over-sampling the digital spatial mark in X based on a factor nx=d1x/d2x and in Y based on a factor ny=d1y/d2y; eroding the dots to be applied so as to leave one dot every nx dots in X and one dot every nx dots in Y; and applying the spatial mark on the support.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.