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Postprocessing of images coded using block DCT at low bit rates.

Sun, Deqing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 86-91). / Abstracts in English and Chinese. / Abstract --- p.i / 摘要 --- p.iii / Contributions --- p.iv / Acknowledgement --- p.vi / Abbreviations --- p.xviii / Notations --- p.xxi / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Image compression and postprocessing --- p.1 / Chapter 1.2 --- A brief review of postprocessing --- p.3 / Chapter 1.3 --- Objective and methodology of the research --- p.7 / Chapter 1.4 --- Thesis organization --- p.8 / Chapter 1.5 --- A note on publication --- p.9 / Chapter 2 --- Background Study --- p.11 / Chapter 2.1 --- Image models --- p.11 / Chapter 2.1.1 --- Minimum edge difference (MED) criterion for block boundaries --- p.12 / Chapter 2.1.2 --- van Beek's edge model for an edge --- p.15 / Chapter 2.1.3 --- Fields of experts (FoE) for an image --- p.16 / Chapter 2.2 --- Degradation models --- p.20 / Chapter 2.2.1 --- Quantization constraint set (QCS) and uniform noise --- p.21 / Chapter 2.2.2 --- Narrow quantization constraint set (NQCS) --- p.22 / Chapter 2.2.3 --- Gaussian noise --- p.22 / Chapter 2.2.4 --- Edge width enlargement after quantization --- p.25 / Chapter 2.3 --- Use of these models for postprocessing --- p.27 / Chapter 2.3.1 --- MED and edge models --- p.27 / Chapter 2.3.2 --- The FoE prior model --- p.27 / Chapter 3 --- Postprocessing using MED and edge models --- p.28 / Chapter 3.1 --- Blocking artifacts suppression by coefficient restoration --- p.29 / Chapter 3.1.1 --- AC coefficient restoration by MED --- p.29 / Chapter 3.1.2 --- General derivation --- p.31 / Chapter 3.2 --- Detailed algorithm --- p.34 / Chapter 3.2.1 --- Edge identification --- p.36 / Chapter 3.2.2 --- Region classification --- p.36 / Chapter 3.2.3 --- Edge reconstruction --- p.37 / Chapter 3.2.4 --- Image reconstruction --- p.37 / Chapter 3.3 --- Experimental results --- p.38 / Chapter 3.3.1 --- Results of the proposed method --- p.38 / Chapter 3.3.2 --- Comparison with one wavelet-based method --- p.39 / Chapter 3.4 --- On the global minimum of the edge difference . . --- p.41 / Chapter 3.4.1 --- The constrained minimization problem . . --- p.41 / Chapter 3.4.2 --- Experimental examination --- p.42 / Chapter 3.4.3 --- Discussions --- p.43 / Chapter 3.5 --- Conclusions --- p.44 / Chapter 4 --- Postprocessing by the MAP criterion using FoE --- p.49 / Chapter 4.1 --- The proposed method --- p.49 / Chapter 4.1.1 --- The MAP criterion --- p.49 / Chapter 4.1.2 --- The optimization problem --- p.51 / Chapter 4.2 --- Experimental results --- p.52 / Chapter 4.2.1 --- Setting algorithm parameters --- p.53 / Chapter 4.2.2 --- Results --- p.56 / Chapter 4.3 --- Investigation on the quantization noise model . . --- p.58 / Chapter 4.4 --- Conclusions --- p.61 / Chapter 5 --- Conclusion --- p.71 / Chapter 5.1 --- Contributions --- p.71 / Chapter 5.1.1 --- Extension of the DCCR algorithm --- p.71 / Chapter 5.1.2 --- Examination of the MED criterion --- p.72 / Chapter 5.1.3 --- Use of the FoE prior in postprocessing . . --- p.72 / Chapter 5.1.4 --- Investigation on the quantization noise model --- p.73 / Chapter 5.2 --- Future work --- p.73 / Chapter 5.2.1 --- Degradation model --- p.73 / Chapter 5.2.2 --- Efficient implementation of the MAP method --- p.74 / Chapter 5.2.3 --- Postprocessing of compressed video --- p.75 / Chapter A --- Detailed derivation of coefficient restoration --- p.76 / Chapter B --- Implementation details of the FoE prior --- p.81 / Chapter B.1 --- The FoE prior model --- p.81 / Chapter B.2 --- Energy function and its gradient --- p.83 / Chapter B.3 --- Conjugate gradient descent method --- p.84 / Bibliography --- p.86

Identiferoai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_325994
Date January 2007
ContributorsSun, Deqing., Chinese University of Hong Kong Graduate School. Division of Electronic Engineering.
Source SetsThe Chinese University of Hong Kong
LanguageEnglish, Chinese
Detected LanguageEnglish
TypeText, bibliography
Formatprint, xxiv, 91 leaves : ill. ; 30 cm.
RightsUse of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

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