We are artists working on the creation of interactive computer systems that use the audiences' participation as essential input for the creation of image structures. In 1998 and 1999 we created two interactive Web...
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We are artists working on the creation of interactive computer systems that use the audiences' participation as essential input for the creation of image structures. In 1998 and 1999 we created two interactive Web sites for the Internet called VERBARIUM and LIFE SPACIES. These two Web sites allow users on the Internet to write text messages that are instantly translated into visual 3D forms. Our custom designed text-to-form editor takes the letters, syntax and sequencing of a text message as generic code and updates the design functions for the creation of 3D forms according to the text message parameters. As the text messages of the different users on the Internet are usually unique and diverse, unique and personal 3D visual forms and shapes can be created by the users.
We present an algorithm for transcoding high-rate compressed bitstreams containing field-coded interlaced video to lower-rate compressed bitstreams containing frame-coded progressive video. We focus on MPEG-2 to H.263...
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We present an algorithm for transcoding high-rate compressed bitstreams containing field-coded interlaced video to lower-rate compressed bitstreams containing frame-coded progressive video. We focus on MPEG-2 to H.263 transcoding, however these results can be extended to other lower-rate video compression standards including MPEG-4 simple profile and MPEG-1. A conventional approach to the transcoding problem involves decoding the input bitstream, spatially and temporally downsampling the decoded frames, and re-encoding the result. The proposed transcoder achieves improved performance by exploiting the details of the MPEG-2 and H.263 compression standards when performing interlaced to progressive (or field to frame) conversion with spatial downsampling and frame-rate reduction. The transcoder reduces the MPEG-2 decoding requirements by temporally downsampling the data at the bitstream level and reduces the H.263 encoding requirements by largely bypassing H.263 motion estimation by reusing the motion vectors and coding modes given in the input bitstream. In software implementations, the proposed approach achieved a 5/spl times/ speedup over the conventional approach with only a 0.3 and 0.5 dB loss in PSNR for the Carousel and Bus sequences.
This paper addresses the problem of bit-rate conversion of a previously compressed video. We provide an MPEG joint transcoder for transcoding several video bitstreams simultaneously. We show that joint transcoding red...
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This paper addresses the problem of bit-rate conversion of a previously compressed video. We provide an MPEG joint transcoder for transcoding several video bitstreams simultaneously. We show that joint transcoding reduces the quality variation between multiple video sequences, as compared to independently transcoding each sequence at a fixed bit rate. Hence, joint transcoding results in a better utilization of the channel capacity. The joint transcoder can be used in a congested communication network as an alternative to data/packet dropping, and in applications which require multiplexing video signals onto a fixed communication channel such as video servers providing video on demand (VOD) service.
A speech content integrity verification scheme integrated with ITU G.723.1 speech coding to minimize the total computational cost is proposed in this research. Speech features relevant to the semantic meaning are extr...
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ISBN:
(纸本)0769510620
A speech content integrity verification scheme integrated with ITU G.723.1 speech coding to minimize the total computational cost is proposed in this research. Speech features relevant to the semantic meaning are extracted, encrypted and attached as the header information. This scheme is not only much faster than cryptographic bitstream integrity algorithms, but also more compatible with a variable of applications. The speech signal could go through recompression, amplification, transcoding, re-sampling, D/A and A/D conversion and minor white noise pollution without triggering the verification alarm.
The MPEG bit-rate transcoder with motion compensation, MC-BRT, that exactly derives from a simplified synchronized decoder/encoder cascade, is considered. Such a transcoder is cost effective but lacks features such as...
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The MPEG bit-rate transcoder with motion compensation, MC-BRT, that exactly derives from a simplified synchronized decoder/encoder cascade, is considered. Such a transcoder is cost effective but lacks features such as spatial and temporal filtering. These features are known to improve the encoder performance at low bit-rates. Such features would be highly desirable in the MC-BRT since most applications now involve critical bit-rates. This paper shows that spatial and motion compensated temporal filtering can be implemented in the MC-BRT at a negligible cost. The filters are analyzed and control variables are given. Simulations reveal the efficiency of the method in terms of noise reduction as well as its great impact on image quality.
With increasing demand of wireless and Internet accesses, the interoperability crossing these two networks becomes increasingly important for modern communications. A transcoding system that translates the coding para...
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With increasing demand of wireless and Internet accesses, the interoperability crossing these two networks becomes increasingly important for modern communications. A transcoding system that translates the coding parameters directly between the GSM and G.729 speech coders is discussed in the present paper. The GSM coder is used for mobile communications while the G.729 is the most favorable speech coder in Internet communications. For Internet/wireless gateway servers, it is evident that the proposed transcoding system requires much less computation than the conventional decode-then-encode (DTE) approach.
Conversion between digital video (DV) for digital video cassette recorder (DVCR) and MPEG-2 intra coding is performed in the DCT domain to reduce conversion steps. Multiplying the matrix by transformed data is used fo...
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ISBN:
(纸本)0780366220
Conversion between digital video (DV) for digital video cassette recorder (DVCR) and MPEG-2 intra coding is performed in the DCT domain to reduce conversion steps. Multiplying the matrix by transformed data is used for 4:1:1-to-4:2:2 chroma format conversion and 2-4-8 DCT mode to 8-8 DCT mode conversion for parallel processing. M-quant of MPEG-2 rate control is computed in the DCT domain.
Various studies show that a basic architecture of an MPEG-2 transcoder consists of a cascaded decoder/encoder. Such a transcoder re-uses the motion vectors and minimizes the changes of macroblock mode. One interesting...
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Various studies show that a basic architecture of an MPEG-2 transcoder consists of a cascaded decoder/encoder. Such a transcoder re-uses the motion vectors and minimizes the changes of macroblock mode. One interesting feature that can be added on this type of transcoder is to insert a translucent logo into the transcoded bit-stream.
Many peoples are using the Internet and many types of devices have emerged. In this situation, a single user wants to continue to work in anytime and anywhere. Current contents service targets specific devices, so tha...
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Many peoples are using the Internet and many types of devices have emerged. In this situation, a single user wants to continue to work in anytime and anywhere. Current contents service targets specific devices, so that it cannot support many different types of devices. To realize continuous and transparent services, we propose a new model of ASP. In our proposed model, User Agent and Application Agent can work together to provide service continuity and device transparency. Then, we implemented a prototype based on this model and evaluated our model. As a conclusion, our model could provide continuous and device transparent service.
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