Abstract
A multiple global affine motion model is proposed for low bit rate video compression. Block-wise motion segmentation is first performed with the number of motion objects L predefined. The affine motion models for multiple MOs are estimated and coded in the frame header. The scaling parameters al, a2, a4 and a5 are coded with a 4-dimensional vector-quantizer (VQ), whose 16 most recently used code words are maintained on line and searched for VQ match, and the 300-word long main code book stored offline. The translational parameters a3 and a6 are coded predicatively as a classical motion vector. L new macro-block modes are added to the standard's list of 7 infra and inter modes. No segmentation information is transmitted, for the mode already indicates that if one of the affine modes is selected by Lagrange rate-distortion optimization. A metric S is defined to measure locality of the motion and will disable use of affine models when a threshold is surpassed. Simulation shows that abut 20-40% of the MB's choose one of the affine modes. When 100kbps or lower band widths are available, the proposed codec not only saves 1-18% bit rate, but also enhances error-resilience in multiple slice frames and reduces blocking artifacts notably.
Original language | English (US) |
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Article number | 18 |
Pages (from-to) | 185-194 |
Number of pages | 10 |
Journal | Proceedings of SPIE - The International Society for Optical Engineering |
Volume | 5685 |
Issue number | PART 1 |
DOIs | |
State | Published - Jul 21 2005 |
Event | Proceedings of SPIE-IS and T Electronic Imaging - Image and Video Communications and Processing 2005 - San Jose, CA, United States Duration: Jan 18 2005 → Jan 20 2005 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering