Real-Time 3D QoE Evaluation of Novel 3D Media - Novel 3D Media Technologies - page 174

Fig. 9.5 Measured image quality of Ballet sequence at QP ¼30 using FR and proposed Near NR
method. (a) color image quality, (b) depth map quality

9.3.1 SSIM Based Near NR Quality Evaluation (“E-SSIM C ”
and “E-SSIM D ” Methods)

Figures 9.6a-e show the scatter plots for the measured image quality (i.e., quality of
both color image and depth map) using the FR and the proposed Near NR methods for
the Orbi , Interview , Ballet , Breakdance sequences , and all the sequences in general
respectively. Each point of this plot corresponds to the measured quality of an image
frame using both FR and proposed method for a given compression level (QPs ranging
from 1 to 50), PLR (0, 3, 5, 10, and 20 % PLRs), and E S / N 0 . According to these figures
it is evident that there is a close relationship between the quality ratings of these
methods regardless of the compression and PLR/( E S / N 0 ) level being considered. In
order to analyze the correlation between the reference and the proposed methods, the
quality ratings are approximated by a second order polynomial [see Eqs. ( 9.14 )and
( 9.15 )] for all the sequences at different compression levels and packet loss rates.
Fitting curves for the proposed and FR methods are shown in each of the scatter plots
in Fig. 9.6 to show the quality of the fitting. This shows a higher degree of correlation
between the proposed method and FR method for both color and depth map images.

2

SSIM C p 1 E-SSIM c ð Þ þ p 2 E-SSIM c ð Þ þ p 3 ð 9 : 14 Þ