Book Chapters

• Why do we need vario-scale maps?

  Maps have always played a significant role in history. They have helped sailors on their Pacific journeys, they have provided information to generals for planning invasions, and they have been used for more pragmatic reasons, such as tax collecting. Nowadays, maps are even more important because they are part of many fields and easily accessible in every smartphone; however, their form differs. While maps on paper still exist, most of them are transferred via the Internet, where users could in principle use the full potential of interactive computer environment, e. g. zooming. Nevertheless, with respect to their creation, retrieval and visualization, maps have stayed more or less the same as in the past. Therefore, this thesis focuses on map creation processed more suitable for interactive computer environment.

  In the next section (Section 1.1), the main issues of the current solution are introduced. Section 1.2 suggests an advantages of the researched system. Main research questions covered in this thesis follow in Section 1.3. Furthermore it highlights the research scope in Section 1.4, the research methodology in Section 1.5, and gives an overview of the thesis structure in Section 1.6.

  Maps have always played a significant role in history. They have helped sailors on their Pacific journeys, they have provided information to generals for planning invasions, and they have been used for more pragmatic reasons, such as tax collecting. Nowadays, maps are even more important because they are part of many fields and easily accessible in every smartphone; however, their form differs. While maps on paper still exist, most of them are transferred via the Internet, where users could in principle use the full potential of interactive computer environment, e. g. zooming. Nevertheless, with respect to their creation, retrieval and visualization, maps have stayed more or less the same as in the past. Therefore, this thesis focuses on map creation processed more suitable for interactive computer environment.

  In the next section (Section 1.1), the main issues of the current solution are introduced. Section 1.2 suggests an advantages of the researched system. Main...

  Maps have always played a significant role in history. They have helped sailors on their Pacific journeys, they have provided information to generals for planning invasions, and they have been used for more pragmatic reasons, such as tax collecting. Nowadays, maps are even more important...

  Radan Šuba

  1-8

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• State of the art in automated map generalization

  Automated map generalization is a difficult, complex and computational very intensive problem. The aim of this chapter is to study existing solutions and state of the art. It also provides context and motivation for why we tackle this problem by applying varioscale approach. In Section 2.1, the paradigm shift in map generalization in a digital environment is studied. We investigate if requirements in the map making process have changed with the transformation from paper to digital environment and if so what are the consequences. Then Section 2.2 investigates how National Mapping Agencies are dealing with automated generalization process in general and what are their recent developments. In Section 2.3, the focus is on the issue of continuous map generalization, which is becoming more researched as an alternative to the map generalization for discrete predefined scales. Section 2.4 demonstrates another problem of digital map environment where the number of map scales available is not sufficient for user interactions. Final remarks are covered in 2.5.

  Automated map generalization is a difficult, complex and computational very intensive problem. The aim of this chapter is to study existing solutions and state of the art. It also provides context and motivation for why we tackle this problem by applying varioscale approach. In Section 2.1, the paradigm shift in map generalization in a digital environment is studied. We investigate if requirements in the map making process have changed with the transformation from paper to digital environment and if so what are the consequences. Then Section 2.2 investigates how National Mapping Agencies are dealing with automated generalization process in general and what are their recent developments. In Section 2.3, the focus is on the issue of continuous map generalization, which is becoming more researched as an alternative to the map generalization for discrete predefined scales. Section 2.4 demonstrates another problem of digital map environment where the number of map scales available is...

  Automated map generalization is a difficult, complex and computational very intensive problem. The aim of this chapter is to study existing solutions and state of the art. It also provides context and motivation for why we tackle this problem by applying varioscale approach. In Section 2.1,...

  Radan Šuba

  9-18

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• Vario-scale data structures

  The previous chapter presents state-of-the-art in map generalization at NMAs’ and continuous generalization. There is a noticeable technological shift towards continuous generalisation which supports interactive map use where users can zoom in, out and navigate more gradual way. Despite some research efforts there is no satisfactory solution yet. Therefore, this chapter introduces the truly smooth vario-scale structure for geographic information where a small step in the scale dimension leads to a small change in representation of geographic features that are represented on the map. With this approach there is no (or minimal) geometric data redundancy and there is no (temporal) delay any more between the availability of data sets at different map scales (as was and is the case with more traditional approaches of multi-scale representations). Moreover, continuous generalisation of real world features is based on the structure that can be used for presenting a smooth zoom action to the user.

  More specific, Section 3.1 and 3.2 provide historical overview of the development and the theoretical framework for vario-scale representations: the tGAP-structure (topological Generalized Area Partitioning). Section 3.3 describes the initial effort to generate the better cartographic content; the concept of constraint tGAP. Section 3.4 explains the 3D SSC (Space-Scale Cube) encoding of 2D truly vario-scale data. Section 3.5 shows idea how to combine more level of details in one map. Section 3.6 summarizes the open questions of the vario-scale concept and it indicates research covered in following chapters. Finally, Section 3.7 presents vario-scale data research in parallel to this PhD for progressive data transfer. Then, Section 3.8 summarises the chapter.

  The previous chapter presents state-of-the-art in map generalization at NMAs’ and continuous generalization. There is a noticeable technological shift towards continuous generalisation which supports interactive map use where users can zoom in, out and navigate more gradual way. Despite some research efforts there is no satisfactory solution yet. Therefore, this chapter introduces the truly smooth vario-scale structure for geographic information where a small step in the scale dimension leads to a small change in representation of geographic features that are represented on the map. With this approach there is no (or minimal) geometric data redundancy and there is no (temporal) delay any more between the availability of data sets at different map scales (as was and is the case with more traditional approaches of multi-scale representations). Moreover, continuous generalisation of real world features is based on the structure that can be used for presenting a smooth zoom action...

  The previous chapter presents state-of-the-art in map generalization at NMAs’ and continuous generalization. There is a noticeable technological shift towards continuous generalisation which supports interactive map use where users can zoom in, out and navigate more gradual way. Despite some...

  Radan Šuba

  19-38

  • Download PDF
• Techniques for better vario-scale map content

  The previous chapters covered the research where the vario-scale structure has been introduced. The main aim of the research was general functionality, performance and optimization. So far, the technical aspects had higher priority than the map content. Therefore, this chapter focuses on improving our development kit for generating varioscale content. It presents a strategy to provide good cartographic results throughout all scales and properly stored in the structure. First, Section 4.1 specifies our target. Section 4.2 presents solutions of other researchers. Section 4.3 introduces concepts and tools which are used later in newly designed process. This is demonstrated on road features in Section 4.4. The section presents the generalization approach for the whole scale range from large scale, where roads are represented as area objects, to mid and small scales, where roads are represented as line objects. In our suggested gradual approach even for one road the representation can be mixed, both area and line, which may provide better transition phase and be

  The previous chapters covered the research where the vario-scale structure has been introduced. The main aim of the research was general functionality, performance and optimization. So far, the technical aspects had higher priority than the map content. Therefore, this chapter focuses on improving our development kit for generating varioscale content. It presents a strategy to provide good cartographic results throughout all scales and properly stored in the structure. First, Section 4.1 specifies our target. Section 4.2 presents solutions of other researchers. Section 4.3 introduces concepts and tools which are used later in newly designed process. This is demonstrated on road features in Section 4.4. The section presents the generalization approach for the whole scale range from large scale, where roads are represented as area objects, to mid and small scales, where roads are represented as line objects. In our suggested gradual approach even for one road the representation can...

  The previous chapters covered the research where the vario-scale structure has been introduced. The main aim of the research was general functionality, performance and optimization. So far, the technical aspects had higher priority than the map content. Therefore, this chapter focuses on...

  Radan Šuba

  39-70

  • Download PDF
• Large vario-scale datasets

  In Chapter 3 the focus was on vario-scale data structure description. This was extended in Chapter 4, where generating better content for this structure was investigated. It showed how the structure has been developed and used in practice, and current technical limitations. One of them is processing really massive dataset with records in order of millions which do not fit in the main memory of computer. It is a notorious and challenging problem. This is especially true in the case of map generalization, where the relationships between (adjacent) features in the map must be considered. Therefore, this chapter presents our solution for automated generalization in vario-scale structure based on the idea of subdividing the workload according to a multi-level structure of the space, allowing parallel processing. More specifically: Section 5.1 specifies our goal. Section 5.2 presents related work and other options to handle large datasets. Section 5.3 explains the principles of our method in more detail. In Section 5.4 modifications of the process specific for road network generalization are introduced. Statistics and a test of real dataset with more than 800 thousand objects are given in Section 5.5, followed by conclusions and the future work related to processing large datasets in Section 5.6.

  In Chapter 3 the focus was on vario-scale data structure description. This was extended in Chapter 4, where generating better content for this structure was investigated. It showed how the structure has been developed and used in practice, and current technical limitations. One of them is processing really massive dataset with records in order of millions which do not fit in the main memory of computer. It is a notorious and challenging problem. This is especially true in the case of map generalization, where the relationships between (adjacent) features in the map must be considered. Therefore, this chapter presents our solution for automated generalization in vario-scale structure based on the idea of subdividing the workload according to a multi-level structure of the space, allowing parallel processing. More specifically: Section 5.1 specifies our goal. Section 5.2 presents related work and other options to handle large datasets. Section 5.3 explains the principles of our...

  In Chapter 3 the focus was on vario-scale data structure description. This was extended in Chapter 4, where generating better content for this structure was investigated. It showed how the structure has been developed and used in practice, and current technical limitations. One of them is...

  Radan Šuba

  71-86

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• Smooth zooming

  Chapter 2 showed that current maps on the Internet are composed of the discrete set of LODs/scale pyramids with big changes of map content and representations. This can lead to confusion for the users when they navigate in the map. Therefore, a conceptual model (SSC) was proposed, see Chapter 3. We believe that, by capturing the whole generalization process in small smooth incremental changes, it is possible to achieve a better user experience e. g. when the user zooms in and out. To verify this hypothesis it is necessary: (1) generate a SSC dataset (2) develop a software prototype where a dataset can be used in its full potential and (3) perform usability test. Hence this chapter will describe the benefits of such as smooth representation in more detail. Section 6.1 gives an introduction to the problem and it suggests our solution. Section 6.2 covers the theoretical background, principle and example of smooth zooming. Section 6.3 presents possible conversion strategies to smooth representation. Section 6.4 explains the software prototype for possible usability testing. This is followed by our initial usability test, which was carry out addition to our plans. More specific, Section 6.5 defines all elements of the testing. Section 6.6 presents preliminary results, and Section 6.7 describes gained experiences. Then, Section 6.8 summarizes possible improvements for the future.

  Chapter 2 showed that current maps on the Internet are composed of the discrete set of LODs/scale pyramids with big changes of map content and representations. This can lead to confusion for the users when they navigate in the map. Therefore, a conceptual model (SSC) was proposed, see Chapter 3. We believe that, by capturing the whole generalization process in small smooth incremental changes, it is possible to achieve a better user experience e. g. when the user zooms in and out. To verify this hypothesis it is necessary: (1) generate a SSC dataset (2) develop a software prototype where a dataset can be used in its full potential and (3) perform usability test. Hence this chapter will describe the benefits of such as smooth representation in more detail. Section 6.1 gives an introduction to the problem and it suggests our solution. Section 6.2 covers the theoretical background, principle and example of smooth zooming. Section 6.3 presents possible conversion strategies to smooth...

  Chapter 2 showed that current maps on the Internet are composed of the discrete set of LODs/scale pyramids with big changes of map content and representations. This can lead to confusion for the users when they navigate in the map. Therefore, a conceptual model (SSC) was proposed, see Chapter...

  Radan Šuba

  87-122

  • Download PDF
• Conclusion

  This thesis has researched further design and development of a system for vario-scale maps. Section 7.1 presents our ultimate vario-scale goal, which will give us perspective to understand issues addressed in the previous chapters such as further development of current generalization tools considering better vario-scale content (Chapter 4), pro- cessing of a large dataset not fitting in main memory (Chapter 5) and smooth user in- teraction (Chapter 6). All these aspects are now brought together in this chapter where they will be summarized and critically evaluated. The main contributions will be put in the context of the thesis by answering the research questions in Section 7.2, mean- while new op r future research will be covered in Section 7.3.

  This thesis has researched further design and development of a system for vario-scale maps. Section 7.1 presents our ultimate vario-scale goal, which will give us perspective to understand issues addressed in the previous chapters such as further development of current generalization tools considering better vario-scale content (Chapter 4), pro- cessing of a large dataset not fitting in main memory (Chapter 5) and smooth user in- teraction (Chapter 6). All these aspects are now brought together in this chapter where they will be summarized and critically evaluated. The main contributions will be put in the context of the thesis by answering the research questions in Section 7.2, mean- while new op r future research will be covered in Section 7.3.

  This thesis has researched further design and development of a system for vario-scale maps. Section 7.1 presents our ultimate vario-scale goal, which will give us perspective to understand issues addressed in the previous chapters such as further development of current generalization tools...

  Radan Šuba

  125-132

  • Download PDF