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  1. 1. Multimedia Research Group Professor Mohammed Ghanbari School of Computer Science and Electronic Engineering University of Essex [email_address]
  2. 2. Research Areas Video Networking Video Over Wireless Video Water Marking Object Segmentation Retrieval and Tracking Multimedia Network and Service Pricing Video Transcoding Video Over Ad Hoc Networks IPTV & Peer-2-Peer Video Streaming Video Compression Video Quality Meter Cross Layer Optimisation
  3. 3. Image Segmentation To separate meaningful objects in an image
  4. 4. Tracking
  5. 5. Search <ul><li>MPEG7 and MPEG21 </li></ul><ul><li>Image/Video segmentation </li></ul><ul><li>Object tracking </li></ul><ul><li>Image/video retrieval, based on </li></ul><ul><ul><ul><li>Colour </li></ul></ul></ul><ul><ul><ul><li>Texture </li></ul></ul></ul><ul><ul><ul><li>Shape </li></ul></ul></ul><ul><ul><ul><li>Motion </li></ul></ul></ul>
  6. 6. 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
  7. 7. P2P vs. Traditional IPTV Client/Server model <ul><li>Consumes Server BW </li></ul><ul><li>Overloads Server CPU </li></ul>Poor performances ! <ul><li>Pros </li></ul><ul><li>Easy to deploy </li></ul><ul><li>No infrastructure modifications </li></ul><ul><li>Software in end-system (client) </li></ul><ul><li>Adding value to end-system </li></ul>P2P Network <ul><li>Cons </li></ul><ul><ul><li>Suffers failures </li></ul></ul><ul><ul><li>Opposite to dedicated entities (routers) </li></ul></ul><ul><ul><li>Bad utilization of network </li></ul></ul><ul><ul><li>Too many duplicated messages </li></ul></ul>
  8. 8. Video Transcoding Transcoder <ul><li>Transcoding Functions: </li></ul><ul><li>Bitrate </li></ul><ul><li>Compression Standard </li></ul><ul><li>Error Resilience </li></ul><ul><li>Resolution </li></ul><ul><ul><li>Spatial </li></ul></ul><ul><ul><li>Temporal </li></ul></ul>Input Bitstream Output Bitstream <ul><li>Input Parameters to analyse: </li></ul><ul><li>Motion Vectors </li></ul><ul><li>Transform Coefficients </li></ul><ul><li>Image Type (I / P / B) </li></ul><ul><li>Macroblock Type </li></ul><ul><ul><li>(16x16, 16x8, 8x8, 4x4) </li></ul></ul><ul><li>Applications: </li></ul><ul><li>Technology Transition (MPEG-2 <-> H.264/AVC) </li></ul><ul><li>Channel Adaptation Satellite/Cable/WiMAX </li></ul><ul><li>Terminal Adaptation </li></ul><ul><ul><li>Screen size </li></ul></ul><ul><ul><li>Processing power </li></ul></ul><ul><ul><li>Energy resources </li></ul></ul>Parameter Processing
  9. 9. Video Quality Meter <ul><ul><li>Objective measure of video quality that correlates well the subjective quality  </li></ul></ul>PSNR = 25.11 VQM = 0.292 PSNR = 25.12 VQM = 0.5574
  10. 10. Loss concealment
  11. 11. Bitstream Switching <ul><li>Switching between different quality (VBR) video streams enabling bandwidth scalability in non scalable video, as in fig. right </li></ul><ul><ul><li>Switching has been done efficiently by combining downstairs reservation scheme with the SP-frames of H.264/AVC improving bandwidth and buffer utilization. </li></ul></ul><ul><li>Switching between different bit rate (CBR) video streams </li></ul><ul><ul><li>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 </li></ul></ul><ul><li>Switching between streams with different robustness (current work) </li></ul><ul><ul><li>Switching between different error resilient techniques of H.264/AVC can achieve PSNR improvement of 4-6 dB </li></ul></ul><ul><ul><li>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 </li></ul></ul>
  12. 12. Video Over Wireless
  13. 13. Multimedia Content Pricing MMCC Content Summarizer Charging Server (3) (4) (5) ( 6) (1) (8) (1) Content Upload (3) Content Characterization and Summarization Multimedia Content Pricing Mechanism (4) Generation of Charging Information (5) Notification Sending Devices Receiving Devices (6) Content Download (8) Delivery Report Billing Centre (7) (2) (2) Charge Collection from sender (7) Charge Collection from Receiver <ul><li>Pricing mechanism allows to charge the content provider and the consumer according to their demand elasticity. </li></ul><ul><li>Consumers nor the content providers decide the price. </li></ul><ul><li>Price can vary according to the type and quality of the content. </li></ul><ul><li>Services such as matching a partner, auctions, advertisement can reach to millions of consumers. </li></ul><ul><li>Delivery mechanism enables content provider to reach billions of potential consumers. </li></ul><ul><li>Cost of delivery is reduced. </li></ul><ul><li>A user who does not own Multimedia Capable devices can also download content from alternative access such as wire line internet. </li></ul><ul><li>Billions of consumer can also become content provider. </li></ul>Content upload Notification by SMS Content download BSC MMCC BTS Internet SMSC WAP Gateway MSC Other Mobile, PSTN & ISDN Networks Application Server Standard HS MM Capable HS MM Capable HS GGSN PCU SGSN Router
  14. 14. Motion Estimation n-1 n n-1 n
  15. 15. VIDEO OVER AD HOC NETWORK Ad hoc Vehicular Network Ad hoc Network Video Captured Received Frames of Video with Some Lost Frames Loss Frames Apply Error Resilience Technique <ul><li>FMO </li></ul><ul><li>MDC </li></ul><ul><li>REDUNDANT </li></ul>
  16. 16. Congestion Control
  17. 17. 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.
  18. 18. 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 Application Transport Network MAC Layer Link Physical