Sub-pixel accurate motion vector estimation and motion-compensated interpolation
US6639944B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 2000 |
| Grant date | Oct 28, 2003 |
| Priority date | — |
| Expiry date | Apr 26, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/523
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Sub-pixel accurate motion estimation from digital video requires interpolation of data. In a symmetrical motion estimator that shifts the neighboring images over complementary fractions (−D/2, D/2) of the vector (D), two such interpolating filters are required. In case of block-matching motion estimation algorithms, the match error of various candidate vectors depends on the quality of the sub-pixel interpolation filter(s). As these filters differ per fractional value of the vector, unintentional preferences for some fractional vector values over other may result. The candidate vectors (D) are split into an integer part (Rnd(D/2)) and a generally non-integer part (D-Rnd(D/2)), as this gives a better accuracy and a lower cost than splitting the candidate vectors (D) exactly conform the temporal position at which the vectors need to be valid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.