Research Overview
Multimedia source coding addresses the representation of speech, sound and moving images using as few bits as practical while retaining the quality needed by the application. In wireless systems, the source codec must also work with channel coding, transceiver design and measures for coping with transmission errors.
The original Southampton research programme explored a longer-term vision of high-quality three-dimensional telepresence. It combined compression of complex audiovisual scenes with error correction and energy-efficient wireless transmission.
Holographic Telepresence
Immersive telepresence aims to reproduce a remote scene with realistic depth and viewpoint changes. It places demanding requirements on acquisition, compression, transmission and display technology. Unlike conventional two-dimensional video, a multi-view system represents the scene from several perspectives, increasing the data volume substantially.
The research programme envisaged error-resilient audio and video codecs, followed by forward error correction and transmission over bandwidth-constrained, potentially noisy wireless channels. Low-power transceiver design was a further requirement for practical deployment.
Stereoscopic and Multi-View Video
A stereoscopic system uses two cameras, separated by a distance approximating human eye spacing, to capture left-eye and right-eye pictures. The paired streams can be stored or transmitted and shown on a compatible stereoscopic display. Many early viewing arrangements require special glasses.
For richer depth representation, the original research considered capturing a scene from approximately 9–16 viewpoints. A multi-view display can then offer changes in perceived perspective without requiring the same viewing method as a conventional two-image stereoscopic system. This was a research objective described by the historical page, not a claim about current NGW equipment.
Because neighbouring cameras record much of the same scene, their streams contain substantial inter-view redundancy. An effective multi-view codec exploits that correlation, for example through prediction across views, to reduce the total transmission rate without unacceptable visual loss.
The original page refers to Inition for stereoscopic technology and Holografika for holographic display technology. These are historical examples rather than endorsements of current products.
Wireless Transmission and Error Resilience
Compressed video is sensitive to errors: a corrupted packet may affect not only the current picture but also subsequent pictures that depend upon it. Therefore, wireless multimedia needs carefully selected error-correcting codes, appropriate protection for more important information, and concealment techniques when errors remain after decoding.
The envisaged evaluation procedure was to introduce representative wireless-channel impairments into compressed multi-view or holographic streams, study the resulting visual distortions, and assess coding and concealment countermeasures. The research plan also proposed subjective viewing tests, potentially using the Southampton Open Wireless Network (SOWN).
Research Papers and Demonstrations
Historical wireless video demonstrations were associated with research on vector quantisation, fractal compression, adaptive coding and error-resilient H.261/H.263 transceivers.
Jürgen Streit and Lajos Hanzo
- Quadtree-based Re-configurable Cordless Videophone Systems
J. Streit and L. Hanzo. IEEE Transactions on Circuits and Systems for Video Technology, vol. 6, no. 2, pp. 225–237, April 1996.
Paper Demo - Dual-mode Vector-quantised Low-rate Cordless Videophone Systems for Indoors and Outdoors Applications
J. Streit and L. Hanzo. Reported by the original page as accepted for IEEE Transactions on Vehicular Technology.
Paper Demo - Adaptive Low-rate Wireless Videophone Schemes
L. Hanzo and J. Streit. IEEE Transactions on Circuits and Systems for Video Technology, vol. 5, no. 4, pp. 305–319, August 1995.
Paper Demo - A Fractal Video Communicator
J. Streit and L. Hanzo. IEEE Vehicular Technology Conference (VTC 1994), Stockholm, pp. 1030–1034.
Paper Demo
Peter Cherriman and Lajos Hanzo
- ARQ-assisted H.261 and H.263-based Programmable Video Transceivers
P. Cherriman, L. Hanzo and R. Lucas. Departmental Research Journal 1995/96.
Paper Demo - Robust H.263 Video Transmission over Mobile Channels in Interference-Limited Environments
P. Cherriman and L. Hanzo. First International Workshop on Wireless Image/Video Communications, Loughborough, UK, 4–5 September 1996, pp. 1–7.
Paper Demo - Power-Controlled H.263-Based Wireless Videophone Performance in Interference-Limited Scenarios
P. Cherriman and L. Hanzo. 7th IEEE PIMRC, Taipei, Taiwan, 15–18 October 1996, vol. 1, pp. 158–162.
Paper Demo - H.261 and H.263-based Programmable Video Transceivers
P. Cherriman and L. Hanzo. IEEE ICCS / ISPACS 1996, Singapore, 25–29 November 1996, vol. 3, pp. 1369–1373.
Paper Demo - Programmable H.263-based Wireless Video Transceivers for Interference-Limited Environments
P. Cherriman and L. Hanzo. Listed on the original page as submitted to IEEE Transactions on Circuits and Systems for Video Technology.
Demo