Definition:Half-pixel accurate motion vectors can be found by interpolating the current frame and reference frame by a factor of two and then using any of the fast block matching algorithms for motion estimation.
In real world video sequences, the true frame-to-frame displacements are unrelated to the integer pixel sampling grids. Thus, the motion prediction accuracy is limited to integer-pel accuracy. In fact, the motion prediction accuracy can be improved by half-pel accurate motion estimation. That is to determine motion vectors with half-pel accuracy. Many coding standards [1], [2] permit motion vectors to be specified to a half-pixel accuracy.
Half-pixel accurate motion vectors can be found by interpolating the current frame and reference frame by a factor of two and then using any of the fast block matching algorithms for motion estimation. The method in finding the half-pel accurate motion vector is illustrated as follows.
- Step 1
Find the motion vector with integer-pixel...
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References
ISO/IEC and ITU-T, “Information Technology — Generic coding of moving pictures and associated audio information — Part 2: Video,” ISO/IEC 13818-2 (MPEG-2) — ITU-T Recommendation H.262, 1996.
ISO/IEC, “Information Technology — Coding of audio-visual object — Part 2: Visual,” ISO/IEC 14496-2 (MPEG-4), 1999.
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© 2006 Springer Science+Business Media, Inc.
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(2006). Motion Estimation with Half-Pixel Accuracy. In: Furht, B. (eds) Encyclopedia of Multimedia. Springer, Boston, MA. https://doi.org/10.1007/0-387-30038-4_132
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DOI: https://doi.org/10.1007/0-387-30038-4_132
Publisher Name: Springer, Boston, MA
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