Page 277 - Video Coding for Mobile Communications Efficiency, Complexity, and Resilience

254 Chapter 10. Error Concealment Using Motion Field Interpolation

Akiyo, M=10, QP=10, Skip=3 Akiyo, M=10, QP=10, Macrblock error rate=20%
31.5 31
ZR-ZR
MFI-BM
31
MFI-MH
30.5 30.5
30
PSNR Y (dB) 29.5 PSNR Y (dB) 30
29
28.5 29.5
28
27.5 29
27 ZR-ZR
MFI-BM
MFI-MH
26.5 28.5
10 20 30 40 50 1 2 3 4
Macroblock error rate (%) Frame skip
(a) Performance over a range of error rates (b) Performance over a range of frame skips
Figure 10.17: Multihypothesis temporal concealment for QSIF AKIYO with M =10 and QP =10
Foreman, M=10, QP=10, Skip=3 Foreman, M=10, QP=10, Macrblock error rate=20%
26 25
ZR-ZR ZR-ZR
MFI-BM MFI-BM
25 24.5
MFI-MH MFI-MH
24 24
23 23.5
23
PSNR Y (dB) 22 PSNR Y (dB) 22.5
21
20 22
19 21.5
18 21
17 20.5
16 20
10 20 30 40 50 1 2 3 4
Macroblock error rate (%) Frame skip
(a) Performance over a range of error rates (b) Performance over a range of frame skips
Figure 10.18: Multihypothesis temporal concealment for QSIF FOREMAN with M =10 and QP =10

This is also con$rmed using Figure 10.20, which shows the subjective
quality of the 102 nd frame of QSIF FOREMAN encoded at 8.33 frames=s with
M =10, QP =10, and corrupted with a random macroblockerror rate of 20%.
Figure 10.20(a) shows the error-free reconstructed frame, whereas
Figure 10.20(b) shows the locations of the damaged macroblocks in addition
to errors propagated from previous frames. Figures 10.20(c), 10.20(d), and
10.20(e) show the same frame when concealed using ZR-ZR, MFI-BM, and
MFI-MH, respectively. The $gures clearly show that the suggested MFI-BM
combination and the multihypothesis MFI-MH technique both outperform the
commonly used ZR-ZR technique. In addition, the $gures clearly show the
superior subjective quality of the MFI-MH technique (Figure 10.20(e)), even