• Journal of Korea Multimedia Society
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• v.18 no.3
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• pp.298-311
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• 2015

Vector data represents a map by its coordinate and Raster data represents a map by its pixel. Since these data types have very large data size, data compression procedure is a compulsory process. This paper compare the results from three different methodologies; GIS (Geographic Information System) vector map data compression using DP(Douglas-Peucker) Simplification algorithm, vector data compression based on Bin classification and the combination between two previous methods. The results shows that the combination between the two methods have the best performance among the three tested methods. The proposed method can achieve 4-9% compression ratio while the other methods show a lower performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.1
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• pp.150-157
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• 2004

For the mobile GIS services, it is not acceptable to construct a new map database only for wireless service due to vast cost. But the existing map database cannot be used directly for the services due to narrow wireless bandwidth and shortage of mobile device resources. This thesis proposes spatial data simplification methods, thus, the existing map database enable the mobile GIS services. The proposing methods are based on the existing map generalization techniques. We extend it to mobile environments, and implement. This thesis also includes the issue of discriminative data simplification technique according to display level and map display interface suitable for mobile devices. Research results an estimated by experiments.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.3
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• pp.35-41
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• 2008

Recently needs for the convergence of CAD and GIS data are increasing, and many studies on converting two systems to each other are being carried out. In this study, to revise and update the building data of digital map using CAD data for construction, the outline of building is abstracted from the CAD data and the outline is generalized to the same level of detail with the building data of digital map. Several line simplification algorithms to generalize the outline are adopted and compared, especially at the view of satisfaction to the drawing rule for digital map. Douglas-Peucker algorithm, Lang's algorithm, Reumann-Witkam algorithm, and Opheim algorithm are applied as the line simplification method. To evaluate the results of these algorithms, visual assessment and variation ratio of the number of points, total length of lines, the area of polygon, and satisfaction ratio to the drawing rule of digital map are analyzed. The result of Lang algorithm and Douglas-Peucker algorithm show superior satisfaction ratio. But general satisfaction ratio is 50~60% for all algorithm. Therefore there seems to be a limit to use these algorithms for the simplification method to update the building data in digital map and it is necessary to develop line simplification algorithm which satisfy the drawing rule well.

• Korean Journal of Computational Design and Engineering
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• v.19 no.1
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• pp.61-67
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• 2014

This paper proposes a procedure enabling the extraction of view-dependent triangular approximations from a height map. In general, procedures to approximate a height map use tree hierarchies. These methods, however, have a limitation in terms of accuracy, because they depend on tree hierarchy than terrain features. To overcome the difficult, we apply the simplification method for triangular meshes to a height map. The proposed procedure maintains full decimation procedure to support multiresolution. The maintenance of decimation procedure results in creation of the groups (trees), each of which consists of vertices that can be merged into one vertex (root node). As the groups have tolerance which is determined by some tests, they support the generation of view-dependent arbitrary triangular meshes.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.1
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• pp.657-666
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• 2009

In GIS area, many line simplification algorithms are studied among generalization methods used for making the building data in the form of digital map from the original line data. On the other hand, there are few studies on the simplification algorithm considering the drawing rules of the digital map in Korea. In this paper, the line simplification algorithm based on the drawing rules is proposed as the methodology to create or update the building data of digital map by extracting the building outline from the CAD data used in construction. To confirm the usefulness of the algorithm, this algorithm and four other effective and general line simplification algorithms (e.g., Douglas-Peucker algorithm) are applied to the same building outlines. Then, the five algorithms are compared on five criteria, the satisfaction degree of the drawing rules, shape similarity, the change rate of the number of points, total length of lines, and the area of polygon. As a result, the proposed algorithm shows the 100% of satisfaction degree to the drawing rules. Also, there is little loss in four other mentioned criteria. Thus, the proposed algorithm in this paper is judged to be effective in updating the building data in digital map with construction drawings.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.481-484
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• 2003

For map services in the mobile environment, it should be considered that resource restriction of the mobile device. Thus, if a map database dedicated to mobile services may not be developed, the spatial data extracted from general map databases should be simplified before transmitting. This paper suggests the mechanism to simplify and modify the spatial data, which are changed to be able to displayed on the mobile devices. This mechanism is based on the map generalization operations and is refined to adapt on mobile phone environment.

• Journal of the Korea Computer Graphics Society
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• v.3 no.1
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• pp.23-28
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• 1997

We reconstruct 3D surface from range image that consists of range map and texture map, and simplify the reconstructed triangular mesh. In this paper, we introduce fast simplification method that is able to glue texture to 3D surface model and adapt to real-time multipled level-of detail. We will verify the efficiency by applying to the scanned data of Korean relics.

• Spatial Information Research
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• v.19 no.1
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• pp.73-82
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• 2011

Recently, demand for the use of cadastral map is increasing in both public and private area. To use cadastral map in web or mobile environment, construction of the multi-representation database(MRDB) that is the compressed into multiple scale from the original map data is recommended. In this study, the map generalization methodology for the cadastral map by applying overlay with topographic map and polygon generalization technique is suggested. This process is composed of three steps, re-constructing the network data of topographic map, polygon merging of parcel lines according to network degree, and applying line simplification techniques. Proposed methodologies are applied to the cadastral map in Suwon area. The result map was generalized into 1:5,000, 1:20,000, 1:100,000 scale, and data compression ratio was shown in 15% 8% 1% level respectively.

• Archives of design research
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• v.20 no.3 s.71
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• pp.345-354
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• 2007

Sometimes characterized graphic map rather than realistic graphic map can help users to understand information more easily. This paper tried to reveal the relation between the methodology to create outline on the map using caricature automatic algorism and level of human cognition. Caricature algorism such as exaggeration transformation algorism, joint transformation algorism and simplification algorism were used to create outline on the map. In order to apply exaggeration transformation algorism and joint transformation algorism, the method to create average form of the object were developed. We survey how users recognize the similarity of the characterized map with the real map when realistic map is simplified by certain value of simplification rate and transformed into certain value of exaggeration rate or joint transformation rate. We also survey how users recognize the similarity differently according to the scale of the map. As a result of this study, the method to calculate the optimal data is developed for users to recognize caricatured map effectively by shifting scale. This data can be used as basic data, when map developers create outline of map with programming code on computer

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.5
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• pp.435-444
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• 2012

Although the multi-scale map database should be constructed for the web map services and location-based services, much part of generation process is based on the manual editing. In this study, the map generalization methodology for automatic construction of multi-scale database from the primary data is proposed. Moreover, the generalization methodology is applied to the real map data and the prototype of multi-scale map dataset is generated. Among the generalization operators, selection/elimination, simplification and amalgamation/aggregation is applied in organized manner. The algorithm and parameters for generalization is determined experimentally considering T$\ddot{o}$pfer's radical law, minimum drawable object of map and visual aspect. The target scale level is five(1:1,000, 1:5,000, 1:25,000, 1:100,000, 1:500,000) and for the target data, new address data and digital topographic map is used.