Technique for estimation of displacement and/or velocity of objects in video scenes
US4218703A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 1979 |
| Grant date | Aug 19, 1980 |
| Priority date | — |
| Expiry date | Mar 16, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/51
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A technique for estimation of displacement and/or velocity of objects in television scenes is recursive, in that each displacement calculation is made using the results of the previous calculation. In a first embodiment, a displaced frame difference DFD (i.e., the intensity difference between a spatial location in the present video frame and a location in the previous frame displaced from that location by an initial displacement estimate) is updated using the initial value of DFD normalized by a measure of local picture activity. In a second embodiment, the update is a multiplicative function of DFD and the intensity gradient at the displaced location in the previous frame.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.