Quality assessment of
The Degradation Category Rating (DCR) subjective test methodology has been used
ITU-T P.910 for additional details.
In short, pairs of original/impaired sequences
have been presented to each test participant. For each pair, participants were asked to
judge the quality of the impaired sequence with respect to the original.
42 individuals have participated in this
test. The participants were non-expert male and female with ages in the range 23 to 32
(most of them were students).
The subjects were screened for normal visual acuity
and color blindness. One of them showed lack of visual acuity and another one was a color blind person.
Two LCD displays of the same model have been
The display and room
characteristics used in the subjective tests are listed below:
- Height of the picture shown in the
screen: 8 cm
- Viewing distance: 64 cm
- Background room illumination: 13.45
- Peak luminance of the LCD screen:
- Luminance of inactive screen: 2.23
- Luminance of background behind the
display: 10.15 lux
- Ratio of luminance of inactive
screen to peak luminance: 0.023
- Ratio of luminance of background
behind the display to peak of luminance: 0.14
original sequences were encoded using the
H.264/AVC JM 12.4 reference software.
The main encoder parameters were as follows:
- Main profile, level 2.0
- GOP structure: 15 frames length, with two B frames
inserted between I/P frames
- 8x8 DCT not allowed
- Maximum of 3 reference frames used for motion estimation
- Low complexity RD optimization mode
- Original JM rate control algorithm
A template for the encoder configuration file can be found
You can get all bitstreams for this test
You can decode all bitstreams using
the batch file provided (just place the JM H.264 decoder and
bitstreams on the same directory).
MOS data is
- Sequence "Australia"
Only the first 250 frames were actually used
(and displayed at 25 frames
- Sequence "Mobile"
A sequence of 900 frames that result from merging Mobile
sequence in the forward direction,
has been encoded.
From the resulting sequence, only the last
part (last 300 frames)
has been used
for subjective quality