There has been tremendous interest in lowbitrateimagecoding over the past few years and a multitude of reports both in the general and technical literature about the technology and its impact on business and the i...
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There has been tremendous interest in lowbitrateimagecoding over the past few years and a multitude of reports both in the general and technical literature about the technology and its impact on business and the individual consumer. This paper provides an overview of directions for the future, particularly with regard to the development of standards. The exploitation of this technology will vary according to the industry: IC companies will manufacture the VLSI defined by the standards;the consumer and professional electronics companies will manufacture multi-media workstations or consumer-orientated products incorporating picture manipulation in its various forms;and telecommunications companies will favour the introduction of the digital video technology, incorporated into multi-media terminals for the digital network.
There has been tremendous interest in lowbitrateimagecoding over the past few years and a multitude of reports both in the general and technical literature about the technology and the impact it will have on busin...
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There has been tremendous interest in lowbitrateimagecoding over the past few years and a multitude of reports both in the general and technical literature about the technology and the impact it will have on business and the individual consumer. The paper provides an overview of directions for the future, particularly with regard to the development of standards. It is clear that there has been considerable interest in the use of photographic images, in a diverse range of applications, as digital technology advances and becomes more widely available. The proliferation of different approaches to imagecoding has created a number of challenges for the industry and the technology will look very different in the 21st century than it does today. The technology will have a significant impact on our lives in a similar way to the telephone and facsimile machines, and the way they have affected our lives today. For one thing, the sharp division between video processing, computers and document image processing will become blurred as the technology develops. One can already see the effects in the political debates taking place regarding the development of the high definition television (HDTV) standards.< >
For improved performance of a predictive coding system used for encoding picture signals at lowbitrates, it is necessary to design not only an efficient predictor, but also an efficient quantizer that produces minim...
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For improved performance of a predictive coding system used for encoding picture signals at lowbitrates, it is necessary to design not only an efficient predictor, but also an efficient quantizer that produces minimum perceptible distortion. We have described a scheme in which a special quantizer called a 'center-clipping quantizer' is used in a ratio PCM coder. The subjective quality of the picture at 1. 58 bit/pel is similar to that of an ADPCM coder at 3 bit/pel, giving an advantage of more than 6 db in performance.
In Photographic Videotex (Picture Prestel) systems, it is desirable to achieve high compression of the picture data, to reduce transmission times and also to minimise the cost and size of data base storage. Work has b...
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In Photographic Videotex (Picture Prestel) systems, it is desirable to achieve high compression of the picture data, to reduce transmission times and also to minimise the cost and size of data base storage. Work has been carried out at BTRL to produce a lowbitrate still color television picture transmission system giving good quality images. This paper discusses a component (Y:U:V) coding scheme employing the Discrete Cosine Transform (DCT), with a block size of 8*8.
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