Screened image reproduction
US4456924A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 3, 1982 |
| Grant date | Jun 26, 1984 |
| Priority date | — |
| Expiry date | May 3, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4058
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
To produce a screened color separation having any screen angle, an original picture is scanned to generate a set of picture values which are digitized and stored. Also a screen function is generated and stored representing a complete two-dimensional period of half-tone screen in the form of a grid-like array of grey-tone values, the mesh of the grid-like array being finer than the scanning raster. To expose a reproduction medium, the screen function values are superimposed on the picture values to develop exposure signals for an exposing plotter. The screen angle is selected by virtually rotating the stored screen function data through the selected angle as it is being recalled from memory.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.