Method for trapping suppression for thin graphical objects using run length encoded data
US6757072B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 29, 2000 |
| Grant date | Jun 29, 2004 |
| Priority date | — |
| Expiry date | Mar 29, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K15/02
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Trapping is a method well known in the graphical arts industry, and provides a remedy for color misregistration defects on printed images. The general technique of trapping involves the placement of a small patches of colored pixels at the edges of colored objects, such that the color associated with these patches appears neutral to the human eye relative to the original colors present. The technique of trapping, however, assumes the objects being trapped are much larger in dimension than the trap zone itself. For small objects, a visible hue shift relative to the original color may occur as a result of the trapping operation. For run length encoded data, the remedy for this is a method that determines the object size by inspecting the run length of a run to be trapped in the fast scan direction, and counting the number of runs above or below that run with an identical color. If the object size is determined to be greater than a specified number of pixels, the trapping operation is performed; otherwise it is suppressed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.