指導教授：莊永裕臺灣大學：資訊網路與多媒體研究所張哲瀚Chang, Che-HanChe-HanChang2014-11-292018-07-052014-11-292018-07-052014http://ntur.lib.ntu.edu.tw//handle/246246/263442Image remapping has received considerable attention in image processing and computer graphics in recent years. Previous approaches only focus on shape preservation while ignore the area change and important line structures in the image. To achieve structure preservation, image remapping must minimize distortion on not only shapes but also areas and line structures. In this dissertation, we propose four structure-preserving approaches for image remapping. The first one is a content-aware image resizing method which simultaneously preserves both salient image features and important line structure properties: parallelism, collinearity and orientation. The second one is a novel projection model for wide angle image visualization. The proposed model is a mapping from a hemisphere to a plane. Our proposed projection have the following properties: shape preserving, line preserving and rectangular outline. The third one is a projection model for panorama viewing. The proposed projection aims at making a good compromise among the preservation of shapes, area and lines. Both the second the third one are instances of the two-step projection model. The last one is a shape-preserving warp for image stitching. The proposed warp is a spatial combination of a projective transformation and a similarity transformation. such combination simultaneously takes into account the accuracy of alignment and the preservation of image structures.中文摘要 iii Abstract iv List of Figures ix Chapter 1 Introduction 1 1.1 Overview of Dissertation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Chapter 2 A Line-Structure-Preserving Approach to Image Resizing 5 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.2 Related work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.3 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.4 Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2.4.1 Energy function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.4.2 Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2.5 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2.6 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Chapter 3 Rectangling Stereographic Projection for Wide-Angle Image Visu- alization 25 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3.2 Related work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 3.3 The proposed projection model . . . . . . . . . . . . . . . . . . . . . . . . . 29 3.3.1 The two-step projection model . . . . . . . . . . . . . . . . . . . . 30 3.3.2 Swung surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3.3.3 The trajectory curve . . . . . . . . . . . . . . . . . . . . . . . . . . 34 3.3.4 Comparisons with previous models . . . . . . . . . . . . . . . . . . 35 3.3.5 Parameter setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 3.4 Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 3.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Chapter 4 A New Projection Model for Panorama Viewing 51 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 4.2 Related Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 4.3 The proposed projection model . . . . . . . . . . . . . . . . . . . . . . . . . 54 4.3.1 The two-step projection model . . . . . . . . . . . . . . . . . . . . 54 4.3.2 Comparisons with previous models . . . . . . . . . . . . . . . . . . 56 4.3.3 Optimizing parameters . . . . . . . . . . . . . . . . . . . . . . . . . 58 4.4 Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 4.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Chapter 5 Shape-Preserving Half-Projective Warps for Image Stitching 67 5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 5.2 Related Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 5.3 The proposed warp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 5.3.1 Analysis of the projective transformation . . . . . . . . . . . . . . 73 5.3.2 Half-projective warp . . . . . . . . . . . . . . . . . . . . . . . . . . 76 5.3.3 C1 extrapolation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 5.4 Image stitching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 5.4.1 Shape-preserving image stitching . . . . . . . . . . . . . . . . . . . 81 5.4.2 Combination with the APAP warp . . . . . . . . . . . . . . . . . . 82 5.5 Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 5.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Chapter 6 Conclusion 89 Bibliography 9129446469 bytesapplication/pdf論文公開時間：2024/07/17論文使用權限：同意有償授權(權利金給回饋本人)影像縮放全景圖投影投影模型廣角影像影像接合影像形變thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/263442/1/ntu-103-D99944009-1.pdf