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Title: | Representation and coding of images using wavelets |
Author(s): | Xiong, Zixiang |
Doctoral Committee Chair(s): | Ramchandran, Kannan |
Department / Program: | Electrical and Computer Engineering |
Discipline: | Electrical Engineering |
Degree Granting Institution: | University of Illinois at Urbana-Champaign |
Degree: | Ph.D. |
Genre: | Dissertation |
Subject(s): | Engineering, Electronics and Electrical |
Abstract: | Recently, there have been intense research activities in the theory of wavelets, driven by its application in a wide variety of areas, especially in image processing. This dissertation presents a body of work addressing the application aspects of wavelets in representation and coding of images. We first introduce a novel space-frequency quantization (SFQ) scheme for wavelet image coding, which jointly optimizes scalar quantization and zerotree quantization using a rate-distortion optimization framework. The SFQ scheme can be viewed as a variant of Shapiro's embedded zerotree image coder (1) with impressive coding gain. We then extend SFQ from wavelet to wavelet packet (possibly space-varying) decompositions, achieving coding performance that is the best in the published literature. We then examine the question of how to choose a space-varying wavelet packet tree representation that minimizes some additive cost function for an image. The idea is that for a practical cost function, some tree structures will perform better than others. We build new libraries of tree-structured bases for image representation with space-varying wavelet packets and devise fast algorithms for finding the best basis from the libraries. Using these algorithms to select the best tree-structured representation with a rate-distortion cost function gives very efficient adaptive compression schemes that are competitive with the best training-based schemes. |
Issue Date: | 1996 |
Type: | Text |
Language: | English |
URI: | http://hdl.handle.net/2142/20956 |
ISBN: | 9780591199703 |
Rights Information: | Copyright 1996 Xiong, Zixiang |
Date Available in IDEALS: | 2011-05-07 |
Identifier in Online Catalog: | AAI9712488 |
OCLC Identifier: | (UMI)AAI9712488 |
This item appears in the following Collection(s)
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Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois -
Dissertations and Theses - Electrical and Computer Engineering
Dissertations and Theses in Electrical and Computer Engineering