Method for generating and storing digitized density thresholds for rastering a half tone original image
US5469516A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 29, 1994 |
| Grant date | Nov 21, 1995 |
| Priority date | — |
| Expiry date | Dec 29, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4058
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The object of the invention is a process for generating and storing digitized density thresholds for defining the grid of a half-tone image. The density thresholds of a section of a grid are stored in a data store as stored words depending on a spot function. In the grid section, several spots with a number of stored words form a multiple grid spot and are periodically arranged beside and above one another. A sorted sequence is found for the stored words of the section in accordance with the spot function. Density thresholds are allocated to the stored words depending on the position in the sorted sequence. The actual number of stored words is found individually for each spot in the section. The sorted sequence is generated according to the current spot function. Before position-dependent thresholds are allocated to the stored words, a center of concentration and possibly final point correction is performed for the spot concerned.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.