Table of Contents
Advertisement
6 PERCEPTUAL EVALUATION OF
VIDEO QUALITY
This chapter discusses OPTICOM's new video quality measurement algorithm in detail. The core of the algorithm
is based on the research, which was done in the KPN laboratories by A.P. Hekstra and J.Beerends. OPTICOM
improved the algorithm further and is now participating in the standardization competition carried out by VQEG
and the ITU-T.
It must be noted that PEVQ is still in a very preliminary state and may therefore be subject to future improvements.
6.1 Structure of the PEVQ Algorithm
PEVQ is a full reference
3
, intrusive
6-1.
The algorithm can be divided up into four separate blocks. The first block – pre-processing stage – is responsible
for the spatial and temporal alignment of the reference and the impaired signal. This process makes sure, that only
3
Full reference measurement means that all information of the original, (not necessarily) undistorted video signal is
required, thus it can be compared to the impaired video signal on a frame-by-frame basis. An alternative to this model
would be the reduced reference model with which the reference signal is represented only by a few parameters
instead of the complete video signal.
4
Intrusive measurements need a reference signal, which is compared to the impaired signal being the result of a
certain device under test (DUT). As a consequence for the DUT this means that a test signal (reference) will have to
be sent through the DUT thus being an intrusion to the device.
4
measurement algorithm for video quality. Its basic structure is shown in Figure
Figure 6-1 Block diagram of PEVQ
A D V A N C E D
E V A L U A T I O N
O F
P E R C E P T U A L
V I D E O
Q U A L I T Y
Page
8 of 12
Advertisement
Table of Contents
