A i - m e i H u a n g A n d Tr u o n g N g u y e n
I E E E , W O R L D O F W I R E L E S S , M O B I L E A N D M U LT I M E D I A N ET W O R K S . (
W O W M O M) , 2 0 0 8
Motion vector processing using bidirectional frame difference in
motioncompensated frame interpolation
Motion compensated frame interpolation(1/3)
Motion compensated frame interpolation(2/3)
• A example
Motion compensated frame interpolation(3/3)
• Although the MV is measured reliably in [4]• Still have some potential issues• In Fig 2 and 3 , the moving object is composed of four
blocks, {B1,B2,B3,B4}• Fig. 3 shows that even MVs are correctly estimated, the
moving object still cannot be reconstructed successfully.• the simplest way to reduce these visual artifacts
is to find the best matches bi-directionally by minimizing the difference between bidirectional predictions.
[4]A.-M. Huang and T. Nguyen. Motion vector processing basedon residual energy information for motion compensated frameinterpolation. in Proc. ICIP’06, pages 2721–2724, 2006.
Bidirectional motion vector processing forMCFI(1/2)
• Use bidirectional MV processing for the received MVF in the current decoder frame ft+1.• we select the best MV from a set of MV candidates
• Vb* , is selected based on the minimum difference between forward and backward predictions.
(2/2)
• Eliminate the ghost artifacts• due to unmatched bidirectional predictions
• Computation is greatly reduced• Use the integer-pixel frame interpolation• affect MV precision .• modify eq. (4) to allow MVs have small deviation from -1 to 1.
SIMULATIONS
• Compare our method with direct MCFI, and vector median filter (VMF).• Test sequence• QVGA size: FORMULA 1, TABLE, and STEFAN• CIF size: FOREMAN, FORMULA 1, FAST FOOD, WALK, and
SILENT• Encode using H.264 , avg. bitrate: 384kbps• even frames are skipped.
• Adopt structure similarity (SSIM)index for qualityassessment.
• luminance• contrast• Structure
Performance
CONCLUSIONS
• The motion vector reliability is analyzed and classified.• we examine how the MV precision affect the
quality of the interpolated frame in the bidirectional MCFI scheme.• we propose a bidirectional MV processing method
by selecting the best MV from neighboring MVs