陳永耀臺灣大學：電機工程學研究所邱保盛Chiou, Pao-ShengPao-ShengChiou2007-11-262018-07-062007-11-262018-07-062005http://ntur.lib.ntu.edu.tw//handle/246246/53574畫面晃動的現象普遍存在於視訊當中，而成因主要來自於攝影機的搖晃。這些搖晃通常是些高頻且不平順的運動。數位式影像穩定化設計的目的便在於消除這些畫面晃動的現象。數位式影像穩定設計主要可以分成兩部分，包括運動的估測和視訊的補償。運動估測的目的在於利用影像處理的技術來估測攝影機的運動行為。視訊補償的目的在於將所估測的運動行為中不必要的運動移除，提供穩定的視訊。 本篇論文主要針對平移和旋轉的畫面晃動提出演算法。運動估測的準確性常影響著影像穩定的效果。當攝影機同時受到平移和旋轉的搖晃時，為提昇運動估測的準確性，本論文提出一個尋找攝影機運動的旋轉中心的概念，且根據這個概念推導出能獲得平移、旋轉和旋轉中心等相關資訊的仿射運動模型。The task of image stabilization systems is to eliminate the image fluctuations caused by unwanted camera movement, while preserving only the intentional camera movement. A digital image stabilization system can be divided into two major parts: one is the motion estimation unit which aims at estimating the global motions of inter-frames and another one is the motion correction unit which aims at eliminating image fluctuations. In this thesis, an algorithm of digital image stabilization which aims at handling both translational and rotational fluctuations is proposed. In order to improve the accuracy of global motion estimation, a concept based on searching the rotational center of a rigid camera motion is proposed and a modified 3-parameter affine motion model is derived. Then, information about the rotation angle, the rotational center and the translation vector can be obtained.摘要 i Abstract ii List of Figures v List of Tables vii Chapter 1 Introduction 1 1.1 Motivation 1 1.2 Classifications of Image Stabilization Systems 3 1.3 Digital Image Stabilization Systems 6 1.4 Problem Formulation 7 1.5 Thesis Organization 8 Chapter 2 Functional Blocks of Digital Image Stabilization Systems 9 2.1 Pre-Processing Unit 10 2.1.1 Image Filtering 10 2.1.2 Edge Detection 11 2.1.3 Bit-plane Decomposition 12 2.2 Motion Estimation Unit 15 2.2.1 Local Motion Estimation Unit 15 2.2.2 Global Motion Estimation Unit 23 2.3 Motion Correction Unit 28 2.3.1 Motion Smoothing Unit 28 2.3.2 Motion Compensation Unit 31 Chapter 3 Modified Three-Parameter Affine Motion Model for Digital Image Stabilization Systems 33 3.1 Hierarchical Block Matching Algorithm 35 3.2 Statistical Analysis 39 3.3 Three-Parameter Affine Motion Model for Translation and Rotation 41 3.4 Modified Three-Parameter Affine Motion Model 48 3.5 Motion Correction 53 Chapter 4 Simulation Results 55 4.1 Verification of the Algorithm for Searching the Real Rotational Center 55 4.2 Stabilization Results of an Image Sequence 61 Chapter 5 Conclusion 67 References 69en-US數位式影像穩定旋轉中心仿射運動模型Digital Image StabilizationRotational CenterAffine Motion Modelthesis