Image Processing Reference
In-Depth Information
Fig. 9.7 Scatter plot of
subjective MOS for overall
3D image quality versus
color image quality
obtained with the proposed
“
E
-
SSIM
C
” method. Each
sample point represents one
test sequence at a given
PLR
/(
E
S
/
N
0
)
Fig. 9.8 Scatter plot of
subjective MOS for overall
3D image quality versus
depth map quality obtained
with the proposed “
E
-
SSIM
D
” method. Each
sample point represents one
test sequence at a given
PLR
/(
E
S
/
N
0
)
(compressed with
QP
¼30). Figure
9.8
shows the mapping between
proposed method for depth map quality evaluation (i.e., “
E
-
SSIM
D
” ratings) and
subjective MOS results. Sequences encoded using both
QP
¼10 and
QP
30 are
used for this mapping. Since average quality ratings are shown for all test points,
only a few number of test points are visible in the scatter plot. This is mainly due to
the fact that subjective quality ratings are obtained for the whole image sequence
(and averaged across all the subjects) and not for each frame. These scatter plots
show the degree of correlation between proposed objective “
Near NR
” measures
and subjective MOS. However, it is difficult to derive a straight forward relation-
ship between these objective measures of color and depth map with the true 3D
video perception due to their usage in viewing and rendering. For instance, depth
¼
10 and
QP
¼
