Halftone dot-growth technique using a dot edge-detection scheme
US7116447B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 2002 |
| Grant date | Oct 3, 2006 |
| Priority date | — |
| Expiry date | Mar 5, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/4055
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for color correcting an original halftone bitmap image by a predefined color correction function to produce a color corrected halftone bitmap image comprising: providing an original halftone bitmap image; estimating the dot area percentage of the original halftone bitmap image in a set of sub-image blocks; calculating an aim dot area percentage, based on a predefined color correction function, for each sub-image block in the original halftone bitmap image, calculating the number of halftone bitmap image pixels to convert to on or off states to produce a modified original halftone bitmap image that has the aim dot area percentage where said value is designated by N, for each sub-image block in the original halftone bitmap image, and converting N pixels in the original halftone bitmap image to either on or off states depending on whether the aim dot area percentage is greater or less than the dot area percentage of the original halftone bitmap image respectively, for each sub-image block in the original halftone bitmap image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.