Multimedia Research Group

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Multimedia Research Group

• Professor Mohammed Ghanbari
• School of Computer Science and Electronic
  Engineering
• University of Essex
• ghan_at_essex.ac.uk

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Research Areas
Video Over Wireless
Object Segmentation Retrieval and Tracking
Video Over Ad Hoc Networks
Video Water Marking
Video Networking
IPTV Peer-2-Peer Video Streaming
Video Compression
Cross Layer Optimisation
Multimedia Network and Service Pricing
Video Transcoding
Video Quality Meter
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Image Segmentation
To separate meaningful objects in an image
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Tracking
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Search
MPEG7 and MPEG21 Image/Video segmentation Object
tracking Image/video retrieval, based
on Colour Texture Shape Motion
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Video Watermarking (Data hiding in video)
Hiding invisible text into an image/video, that
may also stand compression
Inserted text into the image
Recovered text
Watermarked image
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P2P vs. Traditional IPTV

• Consumes Server BW
• Overloads Server CPU

Client/Server model
Poor performances !

• Cons
• Suffers failures
• Opposite to dedicated entities (routers)
• Bad utilization of network
• Too many duplicated messages

• Pros
• Easy to deploy
• No infrastructure modifications
• Software in end-system (client)
• Adding value to end-system

P2P Network
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Video Transcoding
Transcoder
Output Bitstream
Parameter Processing
Input Bitstream

• Transcoding Functions
• Bitrate
• Compression Standard
• Error Resilience
• Resolution
• Spatial
• Temporal

• Applications
• Technology Transition (MPEG-2 lt-gt H.264/AVC)
• Channel Adaptation Satellite/Cable/WiMAX
• Terminal Adaptation
• Screen size
• Processing power
• Energy resources

• Input Parameters to analyse
• Motion Vectors
• Transform Coefficients
• Image Type (I / P / B)
• Macroblock Type
• (16x16, 16x8, 8x8, 4x4)

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Video Quality Meter
Objective measure of video quality that
correlates well the subjective quality 
PSNR 25.11 VQM 0.292
PSNR 25.12 VQM 0.5574
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Loss concealment
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Bitstream Switching
Switching between different quality (VBR) video
streams enabling bandwidth scalability in non
scalable video, as in fig. right Switching has
been done efficiently by combining downstairs
reservation scheme with the SP-frames of
H.264/AVC improving bandwidth and buffer
utilization. Switching between different bit rate
(CBR) video streams Sp-frames have been
implemented in CBR and it has been observed that
the behaviour of these frames are similar to that
of the SP-frames for VBR video Switching between
streams with different robustness (current
work) Switching between different error resilient
techniques of H.264/AVC can achieve PSNR
improvement of 4-6 dB Best quantization parameter
for SP-frame is to be calculated, for which the
performance of the SP-frame is better than
I-frames for bitrate and close to P-frames for
PSNR, as in fig. to right
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Video Over Wireless
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Multimedia Content Pricing

• Pricing mechanism allows to charge the content
  provider and the consumer according to their
  demand elasticity.
• Consumers nor the content providers decide the
  price.
• Price can vary according to the type and quality
  of the content.
• Services such as matching a partner, auctions,
  advertisement can reach to millions of consumers.

Multimedia Content Pricing Mechanism
(2) Charge Collection from sender
(7) Charge Collection from Receiver
Billing Centre
(1) Content Upload
(5) Notification

• Delivery mechanism enables content provider to
  reach billions of potential consumers.
• Cost of delivery is reduced.
• A user who does not own Multimedia Capable
  devices can also download content from
  alternative access such as wire line internet.
• Billions of consumer can also become content
  provider.

(7)
(2)
(5)
(1)
Receiving Devices
Sending Devices
MMCC
(6)
(8)
(3)
(4)
(6) Content Download
(8) Delivery Report
Content Summarizer
Charging Server
(3) Content Characterization and Summarization
(4) Generation of Charging Information
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Motion Estimation
n-1
n-1
n
n
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VIDEO OVER AD HOC NETWORK
Ad hoc Network
Ad hoc Vehicular Network
Apply Error Resilience Technique
Received Frames of Video with Some Lost Frames
Video Captured

• FMO
• MDC
• REDUNDANT

Loss Frames
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Congestion Control
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VIDEO OVER WIRELESS
Our main coal is to improve the Quality of
Service (QOS) of the video over Wireless by find
a suitable algorithms for
1-Data partitioning of the encoded video
packets. 2-Adaptive bit streaming. 3-Forward
Error Correction. 4- Power allocation.
Wireless System WiMAX IEEE 802.16-2004. Video
type IPTV, Video phone, Video conferences.
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Cross Layer Optimisation
Application Link PHY instead of using
target BER power adaptation, consider modifying
the target BER based on application requirements
Application Link performance gain in end to
end SNR by joint channel coding and compression
for video over wireless
Routing Link performance improvement
in percentage of packets not meeting a delay
deadline through joint rate allocation and
routing
MAC Routing performance gain in
channel capacity via joint MAC/routing protocol
design
(MAC PHY) performance gain in
channel utilization through channel reservation
based on physical layer parameters