Reproduction of halftone original with reduced moire
US4926267A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 26, 1989 |
| Grant date | May 15, 1990 |
| Priority date | — |
| Expiry date | May 26, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/40075
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and system for reproducing halftone originals utilizing threshold gray level values of the scanned pixels of the halftone original to determine adjacent pairs of pixels bordering the edges of the halftone dots. Edge errors for the adjacent pairs of pixels are determined using the scanned gray level values and a threshold value. A processing window defines sub-arrays of pixels whose thresholded gray level values are processed based on the edge errors. For each sub-array, the edge errors of the adjacent pairs of pixels are summed. The thresholded values of the adjacent pairs of pixels are then selectively changed in the order of pixel pairs of descending edge error until the number of values changed equals the closest integer to the summed edge error.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.