Telecine conversion detection for progressive scan playback
US7391468B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 24, 2004 |
| Grant date | Jun 24, 2008 |
| Priority date | — |
| Expiry date | Apr 22, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/012
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A moving average filter with a weighting factor calculates a continuously programmable threshold to determine whether fields could be considered identical or not. This decision is used to detect the cadence of a TELECINE encoded video signal. This moving average filter is also used for detecting the presence of still images in the video data stream by detecting total difference in Y (luminance) of the fields and then calculating the average difference in luminance (Y) of the field. This average difference in luminance value indicates a degree of difference between fields. For two frames of data input to the system, each having two fields, a difference is calculated between the luminance values of the two top fields for each frame. From this difference value a maximum absolute difference history is stored, along with the Sum of Absolute Differences (SAD). The programmable threshold is then calculated by summing the saturated SAD history over time. If the present SAD is less than the program threshold, then a low point is detected (e.g., small difference between two fields) and if it follows TELECINE pattern, then the cadence of TELECINE is indicated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.