Method and apparatus for identifying video fields produced by film sources
US5689301A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1994 |
| Grant date | Nov 18, 1997 |
| Priority date | — |
| Expiry date | Dec 30, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/0115
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A first pixel of a given field is compared with second and third vertically aligned pixels of corresponding horizontal position of an adjacent field to produce, for each first pixel, a pixel difference signal having a value of zero if the value of the first pixel is intermediate the values of the second and third pixels, the difference signal otherwise having a value equal to the absolute value of a difference between the value of the first pixel and the value of one of the second and third pixels having a value closest to that of first pixel. The pixel difference signals are accumulated over a predetermined portion of one field period of the video signal to provide a field difference signal which is analyzed by a group of five correlators for patterns characteristic of 2-2 pull-down or 3-2 pull-down film mode sources. Flags are produced for identifying film mode operation and for identifying which of the adjacent fields to use in subsequent video processing such as de-interlacing or flicker reduction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.