Quantizer selection based on region complexities derived using a rate distortion model
US6539124B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 17, 1999 |
| Grant date | Mar 25, 2003 |
| Priority date | — |
| Expiry date | Aug 17, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/61
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
For video compression processing, each frame in a video sequence is segmented into one or more different regions, where the macroblocks of each region are to be encoded using the same quantizer value, but the quantizer value can vary between regions in a frame. For example, for the videophone or video-conferencing paradigm of one or more “talking heads” in front of a relatively static background, each frame is segmented into a foreground region corresponding to the talking head, a background region corresponding to the static background, and an intervening transition region. An encoding complexity measure is generated for each macroblock of the previous frame using a (e.g., first-order) rate distortion model and the resulting macroblock-level encoding complexities are used to generate an average encoding complexity for each region. These region complexities are then used to select quantizer values for each region in the current frame, e.g., iteratively until the target bit rate for the frame is satisfied to within a specified tolerance range. The selected quantizer values may be modified based on spatial and/or temporal constraints to satisfy spatial requirements of the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.