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Wireless Image/Video Communications, 1996., First International Workshop on

Date 4-5 Sept. 1996

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  • Proceedings of First International Workshop on Wireless Image/Video Communications

    Publication Year: 1996
    Request permission for commercial reuse | PDF file iconPDF (290 KB)
    Freely Available from IEEE
  • Principal components analysis for tracking of facial features

    Publication Year: 1996, Page(s):32 - 37
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (428 KB)

    A new method of tracking the position of important facial features in `head-and-shoulders' sequences is presented for low bit-rate wireless communication. The initial part of the analysed sequence is decomposed into sub-images containing important facial features. Tracking of the facial features in subsequent frames is based on this set of sub-images View full abstract»

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  • Video coding using motion compensation with polynomial motion vector fields

    Publication Year: 1996, Page(s):26 - 31
    Cited by:  Papers (7)  |  Patents (33)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (464 KB)

    This paper presents novel methods for motion compensated prediction and prediction error coding of video sequences. The scheme utilises segmentation of the video frames into nonregularly shaped segments composed of small square blocks which can be encoded with a very low number of bits. This two-step segmentation is obtained by quadtree-like splitting of image blocks followed by a motion assisted ... View full abstract»

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  • The interactive multifunctional communication terminal

    Publication Year: 1996, Page(s):134 - 142
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (708 KB)

    Current developments in the working/business environment and society demand quick information exchange at your fingertip. Some contradictory effects are: the ever increasing amount of information; multinational split teams at remote locations; small office/home office (SOHO); more travel, even abroad-increased cost. This situation demands for enhanced visual communication systems, preferably porta... View full abstract»

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  • Wireless video: the impact of the multiplexing layer on error resilience

    Publication Year: 1996, Page(s):20 - 25
    Cited by:  Patents (6)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (516 KB)

    The interest that has been shown in the provision of mobile communications systems has led to the study of real time video traffic over wireless and other error prone networks. Many of the papers in this area employ the MPEG-2 video coding algorithm and provide experimental results of the decoded image quality derived from using only the effect of cell loss on the MPEG-2 video layer. In a practica... View full abstract»

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  • H.263 compatible video coding and transmission

    Publication Year: 1996, Page(s):115 - 120
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (492 KB)

    This paper presents an efficient scaleable subband based coding scheme suitable for multilayer transmission over mobile channels. The method is capable of encoding and decoding video in a hierarchical multiresolution fashion with full compatibility to ITU T H.263. In this approach the higher frequency decomposed bands of the prediction error signal are each encoded by a combination of DCT, uniform... View full abstract»

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  • Source-controlled channel decoding in image transmission

    Publication Year: 1996, Page(s):14 - 19
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1124 KB)

    With the fast growing importance of wireless image communication, the need to deal with fading and other channel distortions arises, in order to enhance the overall throughput and quality of transmitted images. Besides the classical way of combined source and channel coding (Modestino and Daut, 1979) we present a new approach by using source-controlled channel decoding (Hagenauer, 1995) that can b... View full abstract»

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  • Robust H.263 compatible transmission for mobile video server access

    Publication Year: 1996, Page(s):8 - 13
    Cited by:  Papers (11)  |  Patents (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (292 KB)

    For mobile video server access, precoded bitstreams have to be transmitted at very low bitrates over error-prone channels. In this paper, we investigate an H.263 compatible approach to robust transmission of stored video bit-streams that is based on a feedback channel. As a side product, our method allows random access without the overhead of periodic I-frames. Results are presented for a data-rat... View full abstract»

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  • Content-based multimedia data access in Internet video communication

    Publication Year: 1996, Page(s):126 - 133
    Cited by:  Patents (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (356 KB)

    This paper presents a platform for the development and evaluation of MPEG-4 functionalities. The implemented functionalities are content-based multimedia data access, content-based manipulation and bitstream editing, hybrid natural and synthetic data combination, content-based scalability. The system was implemented with Java View full abstract»

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  • Information theoretic based design of hierarchical channel coding and modulation on mobile radio channels

    Publication Year: 1996, Page(s):85 - 90
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (228 KB)

    For the transmission of video on time variant mobile radio channels we discuss a self-adapting hierarchical channel coding scheme. Based on the cutoff rate for multilevel coding on fading channels we derive a procedure for the joint design of unequal error protection and clustered signal constellation View full abstract»

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  • Scalable multiresolution video coding using subband decomposition

    Publication Year: 1996, Page(s):109 - 114
    Cited by:  Papers (4)  |  Patents (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (280 KB)

    A subband approach to scalable multiresolution video coding is presented. In a first step of experiments this scheme is applied to the coding of I-frames, where bit rate savings up to 21.1% compared with MPEG-2 spatial scalability are achieved. In a next step it will be used for inter-frame coding of P- and B-frames View full abstract»

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  • Robust H.263 video transmission over mobile channels in interference limited environments

    Publication Year: 1996, Page(s):1 - 7
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (428 KB)

    The cellular channel capacity of conventional cells is shown to vary dramatically as a function of the distance from the base station. An intelligent 7.3 kBaud adaptive videophone transceiver is contrived, in order to exploit the higher channel capacity of uninterfered cell areas and to satisfy the prevalent system optimisation criteria. The system employed an enhanced H.263-compatible video codec... View full abstract»

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  • Chrominance vector quantization for cellular video-telephony

    Publication Year: 1996, Page(s):57 - 62
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (316 KB)

    The paper describes a vector quantization technique which can be added to a standard codec, like H.263, in order to improve its performance for very high compression. The main idea is to convert two chrominance components of a video-telephone signal into one scalar signal. This scalar chrominance signal is then compressed in a motion compensated coder. The crucial problem is proper ordering of the... View full abstract»

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  • Image compression algorithm using local edge detection

    Publication Year: 1996, Page(s):68 - 73
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1204 KB)

    An algorithm to improve block truncation coding for image compression is proposed. Images to be compressed are first differentiated and edge information is extracted by investigation of the histogram of small nonoverlapping blocks of the differential image. The image is classified into visually active and visually continuous blocks which are then coded individually View full abstract»

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  • Fixed-rate video codecs for wireless systems

    Publication Year: 1996, Page(s):91 - 98
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (500 KB)

    A comparative study of arbitrarily programmable, but fixed-rate videophone codecs using quarter common intermediate format (QCIF) video sequences scanned at 10 frames/s is offered. These codecs were designed to allow direct replacement of mobile radio voice codecs in second generation wireless systems, such as the Pan-European GSM, the American IS-54 and IS-95 as well as the Japanese systems, oper... View full abstract»

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  • Efficient partitioning of coded video bitstreams for multi-channel wireless transmission

    Publication Year: 1996, Page(s):105 - 108
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (232 KB)

    This paper introduces an efficient technique for dividing a pre-coded MPEG-2 bitstream into an arbitrary number of partitions, in decreasing order of visual importance. For a fixed partition size ratio, this has been achieved by VLC code interleaving within a macroblock or group of macroblocks. The algorithm is capable of recreating a syntactically correct bitstream, regardless of the error rate o... View full abstract»

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  • Simulation study of multipath fading effects on integrated video, voice and data transmission in asynchronous BPSK-DS/CDMA systems

    Publication Year: 1996, Page(s):99 - 104
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (468 KB)

    This paper propose an easy way to integrate VBR (variable bit rate) services in asynchronous DS/CDMA: each user is assigned a unique code. One user's VBR service can exceed channel bandwidth when new virtual channels that employ identical spreading codes are opened in parallel. A self-control mechanism has to be applied then to guarantee bit-asynchronism View full abstract»

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  • Coder-oriented matching criteria for motion estimation

    Publication Year: 1996, Page(s):38 - 42
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (260 KB)

    Classical matching criteria for motion estimation determine the match quality by operating in the spatial domain. The resulting displaced frame difference signal is, however, compressed by means of frequency transformations, and any optimal matching criteria should estimate the cost of coding the composite bit stream. Such criteria are presented in this paper and shown to offer some improvement in... View full abstract»

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  • Encoding temporal subband video signals

    Publication Year: 1996, Page(s):121 - 125
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (252 KB)

    A hybrid video codec employing temporal subband coding, motion compensated discrete cosine transform (DCT) and vector quantization (VQ) is proposed. The lowest subband with similar characteristics to the original images uses H.261/263-type encoding. On the other hand, the higher subband signals contain temporal changes and edge information. Various encoding methods are explored and subsampling wit... View full abstract»

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  • Wavelet video transmission over tactical wireless channels

    Publication Year: 1996, Page(s):74 - 79
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (416 KB)

    In this paper, an error resilient, wavelet-based compression algorithm is studied for the transmission of images and video over severely band-limited tactical communications channels. The underlying communications system uses both direct sequence spreading and fast frequency hopping to provide anti-jam capability. As a result of the hopping, noncoherent detection is used. The bit rate available fo... View full abstract»

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  • Non-linear quantisation effects in digital colour systems

    Publication Year: 1996, Page(s):63 - 67
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (388 KB)

    This paper shows that quantisation of colour pixels, essential to digital imagery, causes non-linear correlation in the permitted values of chromaticity coordinates in linear-intensity CIE colour spaces. It follows that colour video and image coding schemes based on these colour spaces will suffer an inherent preference for certain chromaticities View full abstract»

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  • A hierarchical image transmission system for multimedia mobile communication

    Publication Year: 1996, Page(s):80 - 84
    Cited by:  Papers (8)  |  Patents (11)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (372 KB)

    This paper proposes a new mobile image transmission system based on the hierarchical modulation scheme for achieving a high quality and high speed digital image transmission in a band-limited fading channel. The proposed system uses a hierarchical QAM (quadrature amplitude modulation) scheme to give unequal transmission reliability depending on the significance of DCT (discrete cosine transform) b... View full abstract»

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  • Networking multimedia system

    Publication Year: 1996, Page(s):143 - 146
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (248 KB)

    This paper is concerned with networked multimedia technologies. It describes the characteristics of the multimedia systems. It studies the World Wide Web for distributed multimedia data. It also presents a useful language Java used to support multimedia information. It presents the author's work on Java to interact with audio files View full abstract»

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  • An entropy coder for segmentation based video compression

    Publication Year: 1996, Page(s):43 - 47
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (424 KB)

    Morphological segmentation has recognised advantages for video compression, especially at lower bit rates. A two stage approach has traditionally been employed to encode the interframe data produced by this algorithm: contour coding of the regions selected for transmission, followed by coding of the data within the regions. In this paper, an effective single stage conditional arithmetic coder is d... View full abstract»

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  • Improving the image quality of block-based video coders by exploiting interblock redundancy

    Publication Year: 1996, Page(s):48 - 56
    Cited by:  Patents (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (1624 KB)

    Narrowband video transmission via ISDN or wireless channels requires high compression factors. Common block-based coders achieve this by taking account of the statistical correlations within the image blocks. Correlations between neighbouring image blocks, however, are neglected. We present an approach using discrete cosine transforms which takes advantage of this additional information hidden in ... View full abstract»

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