Suppression of sawtooth artifacts in an interlace-to-progressive converted signal
US5625421A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1994 |
| Grant date | Apr 29, 1997 |
| Priority date | — |
| Expiry date | Jan 14, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S348/911
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Jagged vertical or diagonal transition artifacts in interlaced to line doubled progressive scan converted television signals are detected and areas of the television picture having such artifacts are subjected to vertical averaging such that the resolution of the jagged transitions is reduced, thereby softening, "greying" or "fuzzing" the jagged transitions and causing them to appear smooth. Thus, highly contrasted lines appearing in a sawtooth pattern, which are extremely perceptible, are replaced with a flash of what might be characterized as "fuzziness," which is not perceptible. The eye no longer perceives the jagged artifacts. Moreover, areas of reduced vertical and horizontal resolution, resulting from the vertical averaging, do not create any new artifacts and are not perceived by the eye. Artifacts are detected by comparing pixels in corresponding positions in the scan lines of the line doubled progressively scanned television signal. The detection scheme looks for sawtooth patterns by determining if there are differences among pixels in more than one set of three adjacent lines. When a sawtooth pattern is detected, the uncorrected signal in the sawtooth region of a scan li…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.