2,032 research outputs found
Study and simulation of low rate video coding schemes
The semiannual report is included. Topics covered include communication, information science, data compression, remote sensing, color mapped images, robust coding scheme for packet video, recursively indexed differential pulse code modulation, image compression technique for use on token ring networks, and joint source/channel coder design
Streaming an image through the eye: The retina seen as a dithered scalable image coder
We propose the design of an original scalable image coder/decoder that is
inspired from the mammalians retina. Our coder accounts for the time-dependent
and also nondeterministic behavior of the actual retina. The present work
brings two main contributions: As a first step, (i) we design a deterministic
image coder mimicking most of the retinal processing stages and then (ii) we
introduce a retinal noise in the coding process, that we model here as a dither
signal, to gain interesting perceptual features. Regarding our first
contribution, our main source of inspiration will be the biologically plausible
model of the retina called Virtual Retina. The main novelty of this coder is to
show that the time-dependent behavior of the retina cells could ensure, in an
implicit way, scalability and bit allocation. Regarding our second
contribution, we reconsider the inner layers of the retina. We emit a possible
interpretation for the non-determinism observed by neurophysiologists in their
output. For this sake, we model the retinal noise that occurs in these layers
by a dither signal. The dithering process that we propose adds several
interesting features to our image coder. The dither noise whitens the
reconstruction error and decorrelates it from the input stimuli. Furthermore,
integrating the dither noise in our coder allows a faster recognition of the
fine details of the image during the decoding process. Our present paper goal
is twofold. First, we aim at mimicking as closely as possible the retina for
the design of a novel image coder while keeping encouraging performances.
Second, we bring a new insight concerning the non-deterministic behavior of the
retina.Comment: arXiv admin note: substantial text overlap with arXiv:1104.155
User-Oriented QoS in Packet Video Delivery
We focus on packet video delivery, with an emphasis on the quality of service perceived by the end-user. A video signal passes through several subsystems, such as the source coder, the network and the decoder. Each of these can impair the information, either by data loss or by introducing delay. We describe how each of the subsystems can be tuned to optimize the quality of the delivered signal, for a given available bit rate in the network. The assessment of end-user quality is not trivial. We present recent research results, which rely on a model of the human visual system
Distributed video coding for wireless video sensor networks: a review of the state-of-the-art architectures
Distributed video coding (DVC) is a relatively new video coding architecture originated from two fundamental theorems namely, Slepian–Wolf and Wyner–Ziv. Recent research developments have made DVC attractive for applications in the emerging domain of wireless video sensor networks (WVSNs). This paper reviews the state-of-the-art DVC architectures with a focus on understanding their opportunities and gaps in addressing the operational requirements and application needs of WVSNs
Distributed multimedia systems
A distributed multimedia system (DMS) is an integrated communication, computing, and information system that enables the processing, management, delivery, and presentation of synchronized multimedia information with quality-of-service guarantees. Multimedia information may include discrete media data, such as text, data, and images, and continuous media data, such as video and audio. Such a system enhances human communications by exploiting both visual and aural senses and provides the ultimate flexibility in work and entertainment, allowing one to collaborate with remote participants, view movies on demand, access on-line digital libraries from the desktop, and so forth. In this paper, we present a technical survey of a DMS. We give an overview of distributed multimedia systems, examine the fundamental concept of digital media, identify the applications, and survey the important enabling technologies.published_or_final_versio
Development and evaluation of packet video schemes
Reflecting the two tasks proposed for the current year, namely a feasibility study of simulating the NASA network, and a study of progressive transmission schemes, are presented. The view of the NASA network, gleaned from the various technical reports made available to use, is provided. Also included is a brief overview of how the current simulator could be modified to accomplish the goal of simulating the NASA network. As the material in this section would be the basis for the actual simulation, it is important to make sure that it is an accurate reflection of the requirements on the simulator. Brief descriptions of the set of progressive transmission algorithms selected for the study are contained. The results available in the literature were obtained under a variety of different assumptions, not all of which are stated. As such, the only way to compare the efficiency and the implementational complexity of the various algorithms is to simulate them
Management of multimedia resources: from a generic information model to its application to an MPEG2 video codec
New open service architectures provide a management framework for telecommunications services, telecommunications networks and computing resources. However, the introduction of multimedia applications in these architectures will require the management of the underlying multimedia resources (e.g., codecs, converters, etc). Multimedia resources are the basic components that support multimedia communications. In this paper, we tackle this issue by proposing a generic management information model for multimedia resources and then instantiate it for the management of an MPEG2 video codec. This information model provides a data representation of the multimedia resources in order to manage them efficiently
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