Method for generating a threshold value matrix for frequency modulated half-toning
US7505177B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 2005 |
| Grant date | Mar 17, 2009 |
| Priority date | — |
| Expiry date | Aug 28, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4051
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for generating a threshold value matrix is used in the frequency-modulated half-toning of the image data to be reproduced. A threshold value matrix for a basic screen is generated in that low-pass filters of different width are applied to the bit patterns generated and the threshold value distribution is changed on the basis of the filtered results. Furthermore, the bit patterns generated are examined for specific part patterns and the threshold value distribution is changed in such a way that undesired part patterns no longer occur and, instead, desired part patterns, preferably rounded forms, are contained in the bit patterns generated. By use of a combination of scaling and/or rotation and/or mirroring of the threshold value matrix of the basic screen, threshold value matrices are generated for the printing inks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.