modelling of quality of experience in no-reference (nr) model
TRANSCRIPT
“Modelling of Quality of Experience (QoE) in No-Reference Model”Mikołaj Leszczuk, Lucjan Janowski,Jakub Nawała
25.11.2016
QoE Measurementin Full-Reference Model
PSNR SSIM VIF VQM
Diagram source: École Polytechnique Fédérale de Lausanne (EPFL), “Objective Quality Assessment”, 15.03.2011, http://mmspg.epfl.ch/page-58337-en.html
QoE Measurementin No-Reference Model
Blockiness Blur Exposure Time Noise Slicing Block Loss
Freezing (Jerkiness) Blackout Contrast Brightness Letterbox Pillarbox
Interlace Flickering Temporal Activity
Spatial Activity
Diagram source: École Polytechnique Fédérale de Lausanne (EPFL), “Objective Quality Assessment”, 15.03.2011, http://mmspg.epfl.ch/page-58337-en.html
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QoE Measurement Software Package Working in No-Reference Model
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15 Independent Quality Indicators» Blackout» Blockiness» Block Loss» Blur» Contrast» Exposure» Flickering» Freezing» Interlacing» Letter-boxing» Noise» Pillar-boxing» Slicing» Spatial Activity (SA)» Temporal Activity (TA)
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Details (1/2)» No need to access
source sequences» Transparent to video
codec:– Operating on
decompressed video frames
– Even HDMI capture
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Details (2/2)
» Utilizes modern multi-threaded architecture of processing units
» Metrics don’t use closed libraries (source code is easily portable)
» Designed modularly (modularity = easier testing and integration)
» Based on our and others’ scientific work
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No Uniform MOS ScaleMapping
» Unknown specific user» Different needs for different scenarios» Difficult to compare our work with others’» Necessity of such mapping definition in future» Partial solution is Support Vector Machine
(SVM) model mapping on Video Quality Metric (VQM)
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VQM Mapping
» All sequences: 1080p from Consumer Digital Video Library (CDVL)
» Source sequences (SRC) split to chunks 2 seconds long
» Total number of chunks: 361» 10 different compression conditions (HRC)» VQM calculated for 2 seconds sequences
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Predictors
» Blockiness» Spatial Activity (SA)» Blur» Noise
» SVM (R-Squared form 0.6 to 0.76)» Linear model (Adjusted R-Squared 0.689)
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Set 1, R2: 0.595
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7Predicted
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Set 1, R2: 0.595
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Set 5, R2: 0.765
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7Predicted
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Set 5, R2: 0.765
Free ImplementationAvailable for Research Purposes
» Our target = easy availability of our work
» Software available on all 3 popular platforms
» Serving as reference implementation for algorithms developed
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Status
» Public funding finished» Looking for cooperation
with business partners to keep project going
» Known partner = known user needs = better addressing them
» Known target group = more precise results
Contacthttp://vq.kt.agh.edu.pl