Browsing by Author "Takahashi, Shigeo"

Now showing 1 - 6 of 6

A Zone-Based Approach for Placing Annotation Labels on Metro Maps
(2011)
Wu, Hsiang-Yun
;
Takahashi, Shigeo
;
Lin, Chun-Cheng
;
Yen, Hsu-Chun
;
工業工程與管理學系
Hand-drawn metro map illustrations often employ both internal and external labels in a way that they can assign enough information such as textual and image annotations to each landmark. Nonetheless, automatically tailoring the aesthetic layout of both textual and image labels together is still a challenging task, due to the complicated shape of the labeling space available around the metro network. In this paper, we present a zone-based approach for placing such annotation labels so that we can fully enhance the aesthetic criteria of the label arrangement. Our algorithm begins by decomposing the map domain into three different zones where we can limit the position of each label according to its type. The optimal positions of labels of each type are evaluated by referring to the zone segmentation over the map. Finally, a new genetic-based approach is introduced to compute the optimal layout of such annotation labels, where the order in which the labels are embedded into the map is improved through the evolutional computation algorithm. We also equipped a semantic zoom functionality, so that we can freely change the position and scale of the metro map.
Designing and Annotating Metro Maps with Loop Lines
(2015)
Wu, Hsiang-Yun
;
Poon, Sheung-Hung
;
Takahashi, Shigeo
;
Arikawa, Masatoshi
;
Lin, Chun-Cheng
Schematic metro maps provide an effective means of simplifying the geographical configuration of public rapid transportation systems. Nonetheless, travelers still find it difficult to identify routes of a specific topology on the maps because it is usually hidden behind the conventional octilinear layout of the entire map. In this paper, we present an approach to designing schematic maps with loop lines, which are drawn as circles together with annotation labels for guiding different traveling purposes. Our idea here is to formulate the aesthetic criteria as mathematical constraints in the mixed-integer programming model, which allows us to either align stations on the loop line at a grid if they are interchange stations or non-interchange stations on a circle otherwise. We then distribute the annotation labels associated with stations on the loop line evenly to the four side boundary of the map domain in order to make full use of the annotation space, while maximally avoiding intersections between leader lines and the metro network by employing a flow network algorithm. Finally, we present several experimental results generated by our prototype system to demonstrate the feasibility of the proposed approach.
One-and-a-Half-Side Boundary Labeling
(2011)
Lin, Chun-Cheng
;
Poon, Sheung-Hung
;
Takahashi, Shigeo
;
Wu, Hsiang-Yun
;
Yen, Hsu-Chun
In boundary labeling, each point site in a rectangular map is connected to a label outside the map by a leader, which may be a rectilinear or a straight-line segment. Among various types of leaders, the so-called type-opo leader consists of three segments (from the site to its associated label) that are orthogonal, then parallel, and then orthogonal to the side to which the label is attached. In this paper, we investigate the so-called 1.5-side boundary labeling, in which, in addition to being connected to the right side of the map directly, type-opo leaders can be routed to the left side temporarily and then finally to the right side. It turns out that allowing type-opo leaders to utilize the left side of a map is beneficial in the sense that it produces a better labeling result; in some cases. To understand this new version of boundary labeling better, we investigate from a computational complexity viewpoint the total leader length minimization problem as well as the bend minimization problem for variants of 1.5-side boundary labeling, which are parameterized by the underlying label size (uniform vs. nonuniform) and port type (fixed-ratio, fixed-position, vs. sliding). For the case of nonuniform labels, the above two problems are intractable in general. We are able to devise pseudopolynomial time solutions for such intractable problems, and also identify the role played by the number of distinct labels in the overall complexity. On the other hand, if labels are identical in size, both problems become solvable in polynomial time. We also characterize the cases for which utilizing the left side for routing type-opo leaders does not help.
Optimized Topological Surgery for Unfolding 3D Meshes
(2011-09-01)
Takahashi, Shigeo
;
Wu, Hsiang-Yun
;
Saw, Seow Hui
;
Lin, Chun-Cheng
;
Yen, Hsu-Chun
Constructing a 3D papercraft model from its unfolding has been fun for both children and adults since we can reproduce virtual 3D models in the real world. However, facilitating the papercraft construction process is still a challenging problem, especially when the shape of the input model is complex in the sense that it has large variation in its surface curvature. This paper presents a new heuristic approach to unfolding 3D triangular meshes without any shape distortions, so that we can construct the 3D papercraft models through simple atomic operations for gluing boundary edges around the 2D unfoldings. Our approach is inspired by the concept of topological surgery, where the appearance of boundary edges of the unfolded closed surface can be encoded using a symbolic representation. To fully simplify the papercraft construction process, we developed a genetic-based algorithm for unfolding the 3D mesh into a single connected patch in general, while optimizing the usage of the paper sheet and balance in the shape of that patch. Several examples together with user studies are included to demonstrate that the proposed approach works well for a broad range of 3D triangular meshes.
Spatially Efficient Design of Annotated Metro Maps
(2013-06-01)
Wu, Hsiang-Yun
;
Takahashi, Shigeo
;
Hirono, Daichi
;
Arikawa, Masatoshi
;
Lin, Chun-Cheng
Annotating metro maps with thumbnail photographs is a commonly used technique for guiding travelers. However, conventional methods usually suffer from small labeling space around the metro stations especially when they are interchange stations served by two or more metro lines. This paper presents an approach for aesthetically designing schematic metro maps while ensuring effective placement of large annotation labels that are sufficiently close to their corresponding stations. Our idea is to distribute such labels in a well-balanced manner to labeling regions around the metro network first and then adjust the lengths of metro line and leader line segments, which allows us to fully maximize the space coverage of the entire annotated map. This is accomplished by incorporating additional constraints into the conventional mixed-integer programming formulation, while we devised a three-step algorithm for accelerating the overall optimization process. We include several design examples to demonstrate the spatial efficiency of the map layout generated using the proposed approach through minimal user intervention.
Travel-Route-Centered Metro Map Layout and Annotation
(2012-06-01)
Wu, Hsiang-Yun
;
Takahashi, Shigeo
;
Lin, Chun-Cheng
;
Yen, Hsu-Chun
;
交大名義發表
When providing travel guides for a specific route in a metro network, we often place the route around the center of the map and annotate stations on the route with thumbnail photographs. Nonetheless, existing methods do not offer an effective means of customizing the network layout in order to accommodate such large annotation labels while preserving its planar embedding. This paper presents a new approach for designing the metro map layout in order to annotate stations on a specific travel route with large annotation labels. Our idea is to elongate the travel route to be straight along the centerline of the map so that we can systematically annotate such stations with external labels. This is accomplished by extending the conventional mixed-integer programming technique for computing octilinear layouts where orientations inherent to the metro line segments are plausibly rearranged. The stations are then connected with external labels through leaders while minimizing intersections with metro lines for enhancing visual clarity. We present several design examples of metro maps and user studies to demonstrate that the proposed aesthetic criteria successfully direct viewers attention to specific travel routes.