Video signal analysis
US9800824B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 11, 2008 |
| Grant date | Oct 24, 2017 |
| Priority date | — |
| Expiry date | Sep 20, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/0115
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In order to detect interlace errors in a video signal, one receives successive digitally coded frames, each frame comprising data for a field of a first type and data for a field of a second type (i.e. a top field and bottom field or vice versa). One then generates for each field of the first type:—a first difference signal (D1 F1) representative of the difference between the field and the second-type field of the previous frame;—a second difference signal (D1 F2) representative of the difference between the field and the second-type field of the same frame; and—a third difference signal (D1 F3) representative of the difference between the field and the second-type field of the following frame. Then, in dependence of the values of said difference signals, a decision signal (wOFlag) is generated indicating an estimated temporal relationship of the field to the second-type field of the same frame. This can be compared with a signal (IDFO) indicating a purported temporal relationship, and an alarm signal (wEFlag) generated in the event of a mismatch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.