As the Internet has evolved, it has become an information, entertainment, retail, and communication source that millions of people use as a matter of routine. Given the diversity of views and the ability to post any k...
As the Internet has evolved, it has become an information, entertainment, retail, and communication source that millions of people use as a matter of routine. Given the diversity of views and the ability to post any kind of information on the Internet, very often, material that is considered objectionable can be easily accessed on the Web. This is particularly problematic when children are able to access the material with ease. This concern has led lawmakers to try and legislate content by passing the Communications Decency Act (CDA) of 1996. However, concerns that the act would violate free speech rights led to the law being struck down. The need to protect children from objectionable material has led to the development of technology to facilitate filtering of Web content. Currently there are several information blocking or filtering applications designed for use on the Web. Examples of such systems include Cyber Patrol~(~R), Cyber Snoop~(TM), Cybersitter~(TM), and Net Nanny~(~R). The filtering methods used by these systems are either list-based or keyword-based filtering. List-based filtering is the simplest one and must be customized for individual users or highly standardized for specific groups of users. As new Web sites appear, the method requires explicit updates of filtering lists. Keyword-based approaches vary in their thoroughness of Web page parsing and keyword checking. Further, they are known to block useful sites (e.g., health information sites that may contain words in a keyword dictionary) and cannot deal with content that uses images or other forms of multimedia. An alternative to list-based or keyword-based filtering is using a label or rating scheme. In this scheme a human or artificial agent rates a site and associates labels with Web sites. Software agents (e.g., content Advisor in Microsoft~(~R) Internet Explorer) process these labels to make decisions about whether to filter a site or allow it to be viewed. This labeling approach requires a st
The problem of jointly controlling the data rates and transmit powers of users, so as to maximize throughput in cellular DS-CDMA networks is addressed. The multicode (MC-CDMA) system, where the processing gain of each...
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The problem of jointly controlling the data rates and transmit powers of users, so as to maximize throughput in cellular DS-CDMA networks is addressed. The multicode (MC-CDMA) system, where the processing gain of each code is fixed and high rate users use multiple codes for transmission, and the variable gain (VG-CDMA) architectures are considered. The throughout maximization problem is formulated as a classical optimization problem, modeling the constraints arising from the data rate requirements and power budgets. Optimal strategies to maximize throughput in both systems are derived. While the MC-CDMA system has a simple optimal rate-power allocation algorithm, the VG-CDMA system has a more complex solution.
Whereas current debates concern more object oriented technologies, such as the MPEG-4 standardization process, this paper would like to state the art concerning the MPEG-2 technology. The standard was adopted 4 years ...
Whereas current debates concern more object oriented technologies, such as the MPEG-4 standardization process, this paper would like to state the art concerning the MPEG-2 technology. The standard was adopted 4 years ago, and is now currently used for broadcasting digital TV worldwide. Some comments and requirements from the first field trials require new generation of MPEG-2 compression systems, and it was the objective of this paper to try to give some inputs for them. — Whereas the first generations were mainly an optimization of the TM5 model with new motion estimators, new bit-rate control strategies and sometimes new mode selection algorithms, this new generation will be adaptive to the picture content and complexity. This adaptation concerns either the input data (such as picture resolution, noise reduction) or the encoder itself (GOP structure, local adaptation, multipass encoding), but also the bandwidth (statistical multiplexing). From the results presented in this paper a 20% to 30% bits saving can be expected on average, and locally more than 50% (for special cases where the encoders fails, i.e. noise, scene cuts, fading,) — After being in the cost and system software, the competition is now clearly on the compression efficiency to add as many programs as possible into one single channel. The new techniques developed and introduced in this phase of optimization will certainly be exploited in future standards such as MPEG-4 or MPEG-7 where respectively segmentation and scene characterization will be key technologies.
The access of high bandwidth multimedia data is generally limited to the network due to the limited network resources, inefficient indexing mechanism and less of semantic interpretations. Currently, most content-based...
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The access of high bandwidth multimedia data is generally limited to the network due to the limited network resources, inefficient indexing mechanism and less of semantic interpretations. Currently, most content-based video content representation involves the segmentation and indexing of video based on scene change and camera/object motion, and such research generally performs off-line video processing. Little research has been done on on-line video processing, which is crucial in video communication applications such as video conferencing, video multicasting and on-line video browsing and retrieval. Our research investigates real-time content-based processing of multicast video over the Internet. New on-line video feature extraction schemes, such as scene change detection, on-line key frame classification, are considered to meet the requirement of real-time video multicasting filtering based on user's profile over the Internet. The annotation and features extracted from multicasted videoconference bitstream by the on-line video content analysis proxies, which are using the proposed video processing algorithms, are output to a separate metadata channel for the further assistance of semantic multicasting of video content. The performance of the proposed algorithms is also demonstrated in the paper.
This paper presents an overview of the aims and objectives of MPEG-4. This standard scheduled for November 1998 addresses content-based interactivity, universal access, robustness in error-prone environments, manipula...
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ISBN:
(纸本)0780344340
This paper presents an overview of the aims and objectives of MPEG-4. This standard scheduled for November 1998 addresses content-based interactivity, universal access, robustness in error-prone environments, manipulation of objects, both synthetic and natural, etc., at various bit rates, quality levels and spatial/temporal resolutions. The standard is designed to accommodate different communication networks, processors and platforms through tools, algorithms and profiles.
content delivery over the Internet, in order to allow universal access, needs to address both the multimedia nature of the content and the capabilities of the diverse client platforms the content is being delivered to...
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ISBN:
(纸本)0819429880
content delivery over the Internet, in order to allow universal access, needs to address both the multimedia nature of the content and the capabilities of the diverse client platforms the content is being delivered to. We present a system that tailors multimediacontent to optimally match the capabilities of the client device requesting it. This system has three key components: (1) a representation scheme called the InfoPyramid (2) A set of transcoders for converting modality or resolution, and (3) a customizer that selects the best content representation to meet the client capabilities while delivering the most value. The InfoPyramid provides a multi-model, multi-resolution representation hierarchy for multimedia. The raw content components, such as text, audio, images, video, etc., are ingested by the system into InfoPyramids. Next, the transcoder populates the InfoPyramid structures with multi-resolution, multi-model versions of the content. The number of possible renditions of the multimediacontent is potentially combinatorial in the number of content elements. The customization module uses the client device characteristics as constraints to pick the best content representation. content value is computed on the basis of publisher preference guidelines and the content transcoding. We illustrate with a system that deliver news stories customized to diverse clients such as workstations, PCs, PDAs, cellular phones, pagers, etc.
A multimedia object is represented by several kinds of feature vectors which are (semi)-automatically extracted. Therefore, a multimedia information system must employ multiple search and indexing mechanisms due to in...
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ISBN:
(纸本)0819429880
A multimedia object is represented by several kinds of feature vectors which are (semi)-automatically extracted. Therefore, a multimedia information system must employ multiple search and indexing mechanisms due to integration of multiple search modalities such as querying for search and for indexing, keywords and other content-based feature vectors extracted from multimedia objects such as color, texture, shape or sketch. However, today there is no indexing method for content based retrieval of such feature combinations and there is an increasing need for multiple-feature indexing in content based multimedia retrieval systems. In this paper, we introduce a new file structure called Spatial Grid File (SGF). This file structure enables to index multimedia objects by different and independent high-dimensional feature vectors. Moreover, with it, complex queries involving combined retrieval can be efficiently performed. It has unique feature in combining set of search modes each having different properties and similarity metrics. The detailed descriptions of SGF and a summary of the results obtained from the experiments are included.
This paper presents a system which employs the accepted notion of melodic pitch contours to support content-based navigation around a body of multimedia documents including MIDI and digital audio files. The system ado...
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This paper presents a new mechanism for mapping data items onto the storage devices of a parallel web sewer The method is based on careful observation of the effects that limit the performance of parallel web sewers a...
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ISBN:
(纸本)081868657X
This paper presents a new mechanism for mapping data items onto the storage devices of a parallel web sewer The method is based on careful observation of the effects that limit the performance of parallel web sewers and by studying the access patterns for these servers. On the basis of these observations a graph theoretic concept is developed and partitioning algorithms are used to allocate the data items. The resulting strategy is investigated and compared to other methods using experiments and typical access patterns from web servers that are in daily use.
The proceedings contains 61 papers from the SPIE International Society for Optical Engineering Journal on Electronic Imaging and multimediasystems II. Topics discussed include: image retrievals;gray image recognition...
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The proceedings contains 61 papers from the SPIE International Society for Optical Engineering Journal on Electronic Imaging and multimediasystems II. Topics discussed include: image retrievals;gray image recognition;content-based image retrieval;color pattern selections;video segmentations;declarative video data retrieval languages;network databases;fast spatial transformations;moving object segmentation methods;anisotropic segmentations;video segmentation algorithms;wavelet-derived gradient computations;dual-band imaging systems;genetic algorithms;thermal image compression systems;multimedia-on-demand services;personal digital assistant (PDA) systems;and real-time nonlinear video authoring systems.
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