Abstract. In this paper we review and discuss some of the current efforts and proposals in the standardization bodies IETF and MPEG for the delivery of MPEG-4 over IP. We address the issues of payload format and media control by... more
Abstract. In this paper we review and discuss some of the current efforts and proposals in the standardization bodies IETF and MPEG for the delivery of MPEG-4 over IP. We address the issues of payload format and media control by describing two architectures that allow for MPEG-4 streaming. Finally, we describe some MPEG-4 over IP streaming experiments in which the
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Keywords: LTS1 Reference LTS-CONF-1991-007 Record created on 2006-06-14, modified on 2016-08-08
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In this chapter, we discuss the specifics of the PROGRESS-TT project and in particular the strategy, methodology and the procedures that have been developed for its implementation and how they came to be instrumental to a program to... more
In this chapter, we discuss the specifics of the PROGRESS-TT project and in particular the strategy, methodology and the procedures that have been developed for its implementation and how they came to be instrumental to a program to improve the capacity of technology transfer organization.
Keywords: LTS1 Reference LTS-ARTICLE-1992-002 Record created on 2006-06-14, modified on 2016-08-08
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In this chapter, we discuss the specifics of the PROGRESS-TT project and in particular the strategy, methodology and the procedures that have been developed for its implementation and how they came to be instrumental to a program to... more
In this chapter, we discuss the specifics of the PROGRESS-TT project and in particular the strategy, methodology and the procedures that have been developed for its implementation and how they came to be instrumental to a program to improve the capacity of technology transfer organization.
Keywords: LTS1 Reference LTS-CONF-1991-008 Record created on 2006-06-14, modified on 2016-08-08
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Over the last two decades, the well known Descartes’ phrase “I think therefore I am” became “I communicate therefore I am”. The importance of communication is recognized at all levels, political, social, economical, even if sometimes one... more
Over the last two decades, the well known Descartes’ phrase “I think therefore I am” became “I communicate therefore I am”. The importance of communication is recognized at all levels, political, social, economical, even if sometimes one forgets to think. Audiovisual signals are the physical support of the information vital for communication.
In this paper we discuss a simple method to improve the lighting condilions of a scene tr videt) sequence. We ficus on modifying the intensities t) existing light sources md on inserting additional virtual lights into a scene. We target... more
In this paper we discuss a simple method to improve the lighting condilions of a scene tr videt) sequence. We ficus on modifying the intensities t) existing light sources md on inserting additional virtual lights into a scene. We target video conferencing applications where typical lighting conditions (i.e. the average office or home enviromnent) are poor. Our model is much simpler and is a departure from approaches such as re-lighting, developed in computer-augmented reality (CAR) where the scene is first reconstructed geometrically by means o[ computer vision techniques. We rely on a well-known illumination equation that takes into account light attenuation, plus lambertian and specular reflection. Our firs scenario models a 3D space in which the image or video frame lies on a 2D plane. Virtual lights are placed in the 3D space md illuminate the 2D image. We then propose a refined model for talking head video sequences where the talking head is detected, tracked and its surface is...
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... The encoder makes these choices on a MB basis with the goal of opti-mizing the total system performance as described in section 3. To minimize the influence of drift in general, we use an embedded coder [lo] to compress each... more
... The encoder makes these choices on a MB basis with the goal of opti-mizing the total system performance as described in section 3. To minimize the influence of drift in general, we use an embedded coder [lo] to compress each individual frame. ...
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In this paper we present some error concealment techniques for MPEG-2 video coded and multiplexed streams damaged by ATM cell losses. Decoder early resynchronization limits the effects of transmission errors by decoding some information... more
In this paper we present some error concealment techniques for MPEG-2 video coded and multiplexed streams damaged by ATM cell losses. Decoder early resynchronization limits the effects of transmission errors by decoding some information that is normally discarded from the damaged MPEG-2 video bitstreams. A part of this information cannot be completely decoded due to its differential coding among macroblocks (DC levels, motion vectors). Three different techniques are presented for the case of DC level recovery in Intra pictures. Two of them are predictive techniques, one operating in the frequency domain and the other in the spatial domain. The third technique provides an exact reconstruction of DC values using special data coded into the user data area of the MPEG-2 video bitstream. For not resynchronized areas classical temporal and spatial concealment techniques are used. These techniques have been tested on a simulated environment which includes an implementation of MPEG-2 elementary video coding and decoding and MPEG-2 system standards. The ATM transmission part has been simulated by means of specialized simulation software. Results relative to the presented concealment techniques are included.
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ABSTRACT
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ABSTRACT An improved video subband coding technique is presented. It is based on a spatially and spectrally localizing subband analysis, followed by scalar quantization and direct arithmetic coding. The quantization and coding parameters... more
ABSTRACT An improved video subband coding technique is presented. It is based on a spatially and spectrally localizing subband analysis, followed by scalar quantization and direct arithmetic coding. The quantization and coding parameters are adapted on the basis of local energy of the subband pixels. The proposed technique automatically achieves near-optimal rate allocation with respect to mean-square error (or alternatively, weighted mean-square error). In addition, because arithmetic coding requires no alphabet extension, the quantized subband pixels can be encoded in an arbitrary order without affecting bit rate. This makes it possible to obtain a good statistical estimate of the quantization resolution required to achieve a certain overall bit rate, based on a relatively small random sample of the subband pixels and their corresponding energies. The proposed technique requires that estimates of the local energy of the subband pixels be encoded and sent to the receiver as side-information. A...
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ABSTRACT In this paper, we describe a novel architecture for content and delivery validation for IPTV systems. The system generates multimedia events derived from IPTV content analysis and its delivery. Events are aggregated, filtered... more
ABSTRACT In this paper, we describe a novel architecture for content and delivery validation for IPTV systems. The system generates multimedia events derived from IPTV content analysis and its delivery. Events are aggregated, filtered and, through a rules-based system, processed and prioritized to provide monitoring and alerting capabilities. Offline event processing along with a video archiving capability allows for detailed forensic analysis. The novelty of the approach includes the correlation and the combination of content-specific and network-specific events in a normalized representation to allow for complex forensic monitoring and alerting. Applications include content security assurance and metadata verification.
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This paper describes a coding control scheme for MPEG-2 which maintains the perceived video quality constant, and is suitable for real-time and low latency encoding. We have chosen a proportional integral derivative (PID) scheme for the... more
This paper describes a coding control scheme for MPEG-2 which maintains the perceived video quality constant, and is suitable for real-time and low latency encoding. We have chosen a proportional integral derivative (PID) scheme for the controller, and we adopt the same approach in designing the particular PID feedback function. The main reason for using a PID feedback function is the good tradeoff that it offers between computational complexity, ease of design, and performance. We have chosen to use a new video quality metric called moving picture quality metric (MPQM). This metric models the human visual system and matches subjective evaluations correctly, outperforming existing quality metrics for video. Simulations results are shown for typical video sequences. A comparison with CBR encoding also is presented.
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This paper examines the performance of the delivery of MPEG-4 video over a realistically emulated EDGE (Enhanced Data for GSM Evolution) wireless network. The video delivery system is based on MPEG-4 video simple profile and on the IETF... more
This paper examines the performance of the delivery of MPEG-4 video over a realistically emulated EDGE (Enhanced Data for GSM Evolution) wireless network. The video delivery system is based on MPEG-4 video simple profile and on the IETF protocols RTSP, RTP, and RTCP for the media delivery and synchronization in compliance with the 3GPP specifications for packet streaming services (PSS).
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ABSTRACT In this paper we propose a complete subband-based codec for image compression purposes, using a new 2D algorithm based on zero-crossing and energy information. Although signal representation based on sign information is... more
ABSTRACT In this paper we propose a complete subband-based codec for image compression purposes, using a new 2D algorithm based on zero-crossing and energy information. Although signal representation based on sign information is attractive from a coding point of view, two major problems inhibited its practical use, namely the large amount of side information needed for obtaining a stable reconstruction and the efficient treatment of inherently 2D signals. The new algorithm significantly improves the reconstruction results obtained in our previous work, thanks to its improved convergence and its capabilities to deal with the two-dimensional nature of the subband image signals. The zero-crossing information is compressed in a lossless way using the JBIG standard and the energy information in a lossy way using an arithmetic coder. Good results have been obtained both at the reconstruction and at the coding level, which show the feasibility of the global scheme.
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ABSTRACT In this paper, we propose a camera motion detection method that can identify pan, tilt and zoom in a video sequence. The proposed method exploits motion features based on the motion cooccurrence matrix, which is able to provide... more
ABSTRACT In this paper, we propose a camera motion detection method that can identify pan, tilt and zoom in a video sequence. The proposed method exploits motion features based on the motion cooccurrence matrix, which is able to provide dominant motion characteristics between two images such as the size of the homogeneous motion area and the direction of motion. We show that motion cooccurrence matrices are quite different for different types of motion and can be used to effectively identify simple camera motion such as pan, tilt and zoom in video sequences. Our method does not rely on the parametric motion model and can be used to qualitatively detect camera motion. Performance of the proposed method is evaluated by experiments for a set of test sequence.
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... 6. REFERENCES [1] D. Gibbon, Z. Liu, and B. Shahraray, "The MIRACLE Video Search Engine," IEEE CCNC 2006, Las Vegas, NV, January 2006. ... [16] Z. Liu, D. Gibbon, E. Zavesky, B. Shahraray, and P. Haffner,... more
... 6. REFERENCES [1] D. Gibbon, Z. Liu, and B. Shahraray, "The MIRACLE Video Search Engine," IEEE CCNC 2006, Las Vegas, NV, January 2006. ... [16] Z. Liu, D. Gibbon, E. Zavesky, B. Shahraray, and P. Haffner, AT&T Research at TRECVID 2007, TRECVID 2007 Workshop ...
Keywords: LTS1 Reference LTS-CONF-1993-047 Record created on 2006-06-14, modified on 2016-08-08
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These Ecole polytechnique federale de Lausanne EPFL, n° 1379 (1995)Section de systemes de communicationInstitut de genie electrique et electroniqueLaboratoire de traitement des signaux 1 Reference doi:10.5075/epfl-thesis-1379Print copy in... more
These Ecole polytechnique federale de Lausanne EPFL, n° 1379 (1995)Section de systemes de communicationInstitut de genie electrique et electroniqueLaboratoire de traitement des signaux 1 Reference doi:10.5075/epfl-thesis-1379Print copy in library catalog Record created on 2005-03-16, modified on 2016-08-08
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