Method and apparatus for generating screened halftone images
US4556918A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1983 |
| Grant date | Dec 3, 1985 |
| Priority date | — |
| Expiry date | Dec 21, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4055
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Apparatus and method for generating screened halftone images, which includes means for assuming an area of halftone dots with desired periodicity and tone reproducibility, subdividing the area into minute cells and setting address values (X, Y) for each of the minute cells, computing out a threshold value of density for each of said cells as a function f (X, Y) of the relevant address values (X, Y), and using the computed value as threshold value of density for the cell, means for obtaining a density-related video signal of the portion of the original corresponding to each of said cells by scanning the original, and means for producing halftone dot signals by comparing the video signals and the threshold value of density with each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.