A robust three-layer, two description image coder /
The advent of multimedia applications has lead to an increased demand for digital images and video. The storage and transmission of these signals in their raw form is very expensive, therefore some type of compression must be used. Image and video compression algorithms based on the Discrete Cosine...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
2000.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=731990481&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The advent of multimedia applications has lead to an increased demand for digital images and video. The storage and transmission of these signals in their raw form is very expensive, therefore some type of compression must be used. Image and video compression algorithms based on the Discrete Cosine Transform (DCT) have been enormously successful and are now used in a number of international image and video coding applications, e.g., the Motion Picture Experts Group (MPEG) video compression standards and the Joint Photographic Experts Group (JPEG) image compression standard. The well-known set partitioning in hierarchical trees (SPIHT) coding scheme employs a discrete wavelet transform and achieves excellent perfor- mance in image compression. These coding schemes provide good tradeoffs in com- pression, system complexity, and image quality. For data transmission across noisy channels, the performance of compression schemes like JPEG, MPEG, and SPIHT can super severely. In this dissertation, we propose a new DCT-based image coder that provides a balance in fives areas: compression, channel error robustness, complexity, progressive transmission, and codec interoperability. We design a unique embedded coding scheme which is denoted as a three-layer, two description image coder. Our coding technique increases robustness to lost information when compared to the traditional progressive coding method and it maintains progressivity. Also, robustness of the layered coder is significantly increased when current error-concealment techniques are employed. We show that the proposed layered image coding scheme provides good performance for practical packet erasure rates. Our research also proposes a transcoding technique that allows interoperability of different kinds of DCT-based image and video codecs. The technique can convert one coding format into our layered coding format in the DCT domain. This approach takes advantage of the similarities in the coders, specifically the DCT block operation, which reduces the transcoding computations and delay. Transcoding with wavelet-based coding schemes requires more computations and complexity because of the two different transform operations. The three-layer, two description image coder offers performance, flexibility, and interoperability unavailable in any existing approach. |
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| Item Description: | Vita. "Major Subject: Electrical Engineering". |
| Physical Description: | xii, 83 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 78-82). |