학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2016. 2. 서진욱.We propose an interactive visualization design tool, called JigsawMap, for analyzing and mapping historical textual cadasters. A cadaster is an official register that records land properties (e.g., location, ownership, value and size) for land valuation and taxation. Such mapping of old and new cadasters can help historians understand the social and economic background of changes in land uses or ownership. JigsawMap can effectively connect the past land survey results to modern cadastral maps. In order to accomplish the connection process, three steps are performed: (1) segmentation of cadastral map, (2) visualization of textual cadastre, (3) and mapping interaction. We conducted usability studies and long term case studies to evaluate JigsawMap, and received positive responses. We summarize the evaluation results and present design guidelines for participatory design projects with historians.
Followed by our study on JigsawMap, we further investigated on each components of our tool for more scalable map connection. First, we designed a hybrid algorithm to semi-automatically segment land pieces on cadastral map. The original JigsawMap provides interface for user to segment land pieces and the experiment result shows that segmentation algorithm accurately extracts the regions. Next, we reconsidered the visual encoding and simplified it to make textual cadastre more scalable. Since the former visual encoding relies on traditional map legend, the visual encoding can be selected based on user expert level. Finally, we redesigned layout algorithm to generate a better initial layout. We used evolution algorithm to articulate ambiguity problem of textual cadastre and the result less suffered from overlapping problem. Overall, our visualization design tool will provide an accurate segmentation result, give the user an option to select visual encoding that suits on their expert level, and generate more readable initial layout which gives an overview of cadastre layout.Chapter 1 Introduction 1
1.1 Background & Motivation 1
1.2 Main Contribution 7
1.3 Organization of the Dissertation 8
Chapter 2 Related Work 11
2.1 Map Data Visualization 11
2.2 Graph Layout Algorithms 13
2.3 Collaborative Map Editing Service 14
2.4 Map Image Segmentation 15
2.5 Premodern Cadastral Maps 17
2.6 Assessing Measures for Cartogram 18
Chapter 3 Visualizing and Mapping Premodern Textual Cadasters to Cadastral Maps 20
3.1 Textual Cadastre 21
3.2 Cadastral Maps 24
3.3 Paper-based Mapping Process and Obstacles 24
3.4 Task Flow in JigsawMap 26
3.5 Design Rationale 32
3.6 Evaluation 34
3.7 Discussion 40
3.8 Design Guidelines When Working with Historians 42
Chapter 4 Accurate Segmentation of Land Regions in Historical Cadastral Maps 44
4.1 Segmentation Pipeline 45
4.2 Preprocessing 46
4.3 Removal of Grid Line 48
4.4 Removal of Characters 52
4.5 Reconstruction of Land Boundaries 53
4.6 Generation of Polygons 55
4.7 Experimental Result 56
4.8 Discussion 59
Chapter 5 Approximating Rectangular Cartogram from Premodern Textual Cadastre 62
5.1 Challenges of the Textual Cadastre Layout 62
5.2 Quality Measures for Assessing Rectangular Cartogram 64
5.3 Quality Measures for Assessing Textual Cadastre 65
5.4 Graph Layout Algorithm 66
5.5 Results 72
5.6 Discussion 73
Chapter 6 Design of Scalable Node Representation for a Large Textual Cadastre 78
6.1 Motivation 78
6.2 Visual Encoding in JigsawMa 80
6.3 Challenges of Current Visual Encoding 81
6.4 Compact Visual Encoding 83
6.5 Results 84
6.6 Discussion 86
Chapter 7 Conclusion 88
Bibliography 90
Abstract in Korean 101Docto
