Daisuke Sakurai, Osamu Saeki, Hamish Carr, Hsiang-Yun Wu, Takahiro Yamamoto, David Duke, Shigeo Takahashi
Interactive Visualization for Singular Fibers of Functions ƒ : ℜ³ → ℜ²
IEEE Transactions on Visualization and Computer Graphics, Vol. 22, No. 1 (Proceedings of IEEE Vis 2015), pp. 945-954, January 2016 [DOI: 10.1109/TVCG.2015.2467433]
Scalar topology in the form of Morse theory has provided computational tools that analyze and visualize data from scientific and engineering tasks. Contracting isocontours to single points encapsulates variations in isocontour connectivity in the Reeb graph. For multivariate data, isocontours generalize to fibers—inverse images of points in the range, and this area is therefore known as fiber topology. However, fiber topology is less fully developed than Morse theory, and current efforts rely on manual visualizations. This paper presents how to accelerate and semi-automate this task through an interface for visualizing fiber singularities of multivariate functions ℜ³ → ℜ². This interface exploits existing conventions of fiber topology, but also introduces a 3D view based on the extension of Reeb graphs to Reeb spaces. Using the Joint Contour Net, a quantized approximation of the Reeb space, this accelerates topological visualization and permits online perturbation to reduce or remove degeneracies in functions under study. Validation of the interface is performed by assessing whether the interface supports the mathematical workflow both of experts and of less experienced mathematicians.

Tetsuya Takahashi, Yoshinori Dobashi, Issei Fujishiro, Tomoyuki Nishita, Ming C. Lin
Implicit formulation for SPH-based viscous fluids
Computer Graphics Forum, Vol. 34, No. 2 (Proceedings of Eurographics 2015), pp. 493-502, May 2015 [DOI: 10.1111/cgf.12578]
We propose a stable and efficient particle-based method for simulating highly viscous fluids that can generate coiling and buckling phenomena and handle variable viscosity. In contrast to previous methods that use explicit integration, our method uses an implicit formulation to improve the robustness of viscosity integration, therefore enabling use of larger time steps and higher viscosities. We use Smoothed Particle Hydrodynamics to solve the full form of viscosity, constructing a sparse linear system with a symmetric positive definite matrix, while exploiting the variational principle that automatically enforces the boundary condition on free surfaces. We also propose a new method for extracting coefficients of the matrix contributed by second-ring neighbor particles to efficiently solve the linear system using a conjugate gradient solver. Several examples demonstrate the robustness and efficiency of our implicit formulation over previous methods and illustrate the versatility of our method.

Takami Yamamoto, Masanori Nakayama, Rui Katsura, Akira Sakamoto, Issei Fujishiro
Development of a pants pattern design system based on 3D body data analysis
IIEEJ Transactions on Image Electronics and Visual Computing, Vol. 3, No. 2, pp. 114-124, December 2015
In this paper, we proposed a pants pattern design system covering its highly precise application to pattern making by analyzing human body measurement data acquired with a 3D scanner. This system is characterized by: (1) being able to analyze data required for the design of pants patterns using an improved 3D human body measurement analysis application, and (2) being provided with automatic pants drafting functions installed in an apparel CAD system using 3D human body measurement data. As a result, individual 3D human body measurement data can be analyzed both accurately and rapidly, thereby enabling pants patterns that comfortably and properly fit the physique of the wearer to be obtained in a short period of time.


井阪 建, 藤代 一成
IFWB: 「第四の壁」を壊す簡易イメージベースモデリング手法
芸術科学会論文誌, Vol. 14, No. 4, pp. 150-159, 2015年9月
本論文では, ユーザが注目対象の画像に対して臨場感をもち得ていない心理的状態「第四の壁」を, 画像内の世界へのウォークスルー体験を実現することによって壊すイメージベースモデリングシステムとして, IFWB (Instant Fourth Wall Breaker) を提案する. 本システムは, 奥行きのある構図をもつ画像を1 枚入力すると, それ以上のユーザ入力を必要とすることなく即座に動作する. 実際のターゲット環境として, スマートフォンやタブレット端末などの軽薄短小なデバイスを想定しており, カメラと同じような感覚で, いつでもどこでも使うことができる.

能野 琴, Hsiang-Yun Wu, 渡辺 一帆, 高橋 成雄, 藤代 一成
画像電子学会誌, Vol. 44, No. 3, pp. 447-456, 2015年7月
高次元データの可視化で広く用いられ,次元間の相関を効果的に把握できる手法のひとつとして,平行座標系が知られている.しかし,平行座標系では,データのサンプル数および次元数の増加に伴い,データに対応する折れ線や次元軸が重なり,視覚的にデータの把握が困難になる視覚的乱雑さが生じる.そこで本論文では,この問題を解決するために,各組の変数間の相関性の分析を通じて複数の座標軸を縮約することにより,全体のデータの次元数を減らして視覚的にわかりやすく平行座標系を描画する手法を提案する.具体的には,以下のような処理を行う.まず,各軸同士の相関係数を類似度として考え,軸をノードとして,類似度の高い軸同士を結ぶ完全グラフに手を加えたグラフを構築する.次に,グラフスペクトル解析によって次元圧縮を行い,各軸の位置を1 次元数直線上に写像し,得られた座標軸の順番に平行座標軸を並び替える.その後,写像した1 次元数直線上において,最近接する軸の併合を順次行い,系統樹を描く.また,上記の操作時には,平行座標軸や系統樹にアニメーション効果を導入することで,座標軸の縮約および展開の過程も視覚的に確認できる.このようにして,平行座標系の軸を縮約することで,高次元データをより少ない座標軸を用いて表示し,データに内在する大局的な振る舞いの視覚的な理解を実現する.さらに,本論文では次元間の相関がより明確に可視化されるかどうかを調べるため,相関にばらつきのあるデータを用いてユーザスタディを実施し,本手法の有効性を示した.

池田 泰成, 松岡徹, 渡辺 一帆, 高橋 成雄, 藤代 一成
電子情報通信学会論文誌D, Vol. J99-D, No. 3, pp. 307-316, 2016年3月 [DOI: 0.14923/transinfj.2015PDP0018]


Issei Fujishiro, Naoki Haga, Masanori Nakayama
SeeGroove: Supporting groove learning through visualization
in Proceedings of Cyberworlds2015, pp. 189–192, Gotland(Sweden), October 2015 [DOI 10.1109/CW.2015.65] [received Best Paper (First Prize) Award]
“Groove” is a global feature of music performance that generalizes the surges, propulsive rhythmic feel, dynamics, and togetherness of sound to reflect overall rhythmic pleasure. Groove is vital to a good performance, though it is claimed that considerable experience is needed to be accumulated for the expression of groove at will. In this work, we propose a general visualization system, called SeeGroove, that allows performers to efficiently comprehend groove in various music genres. For each genre, the standard MIDI dataset was extracted from actual performances of professional players in advance. The system then takes the difference between an input data of performance and the standard of a chosen genre to quantify the degree of groove of the performance. To visualize the differences, the user is allowed to rely on any combination of two modes and two views of designated visualization in accordance with his/her preferences and target information.

Yuki Ohtaka, Shigeo Takahashi, Hsiang-Yun Wu, Naoya Ohta
Information for Exploring Optimal Light Source Placements
accepted for presentation by SmartGraphics2015, Chengdu (China), August 2015
Exploring optimal light sources for effectively rendering 3D scenes has been an important research theme especially in the application to computer graphics and visualization problems. Although conventional techniques provide visually plausible solutions to this problem, they did not seek meaningful correlations between proper light sources and their related attribute values. This paper presents an approach to exploring optimal light source placements by taking into account its correlations with such attribute values. Our idea lies in the novel combination of existing formulations by taking advantage of information theory. We first employ the quantized intensity level as the first attribute value together with the conventional illumination entropy so as to find the best light placement as that having the maximum mutual information. Meaningful relationships with viewpoints as the second attribute value are then studied by constructing a joint histogram of the rendered scenes, which is the quantized version of a 3D volume composed by the screen space and intensity levels. The feasibility of the proposed formulation is demonstrated through several experimental results together with simulation of illumination environments in a virtual spacecraft mission.

Fumiya Sato, Hsiang-Yun Wu, Shigeo Takahashi, Masatoshi Arikawa
Extracting important routes from illustration maps using kernel density estimation
accepted for presentation by SmartGraphics2015, Chengdu (China), August 2015
Illustration maps often direct our visual attention to the specific route with geographic symbols and annotation labels associated with important landmarks. This inspires us to evaluate the quality of such maps by analyzing the spatial distribution of visual attention over the map domain. In this paper, we introduce kernel density estimation in order to identify important routes that are implicitly designated by the map designers. Our algorithm begins by composing the density field as a combination of Gaussian kernels centered on the landmarks. The algorithm then allows us to extract an important route on the map as the trajectory of a ball running along the valley of the density field. We conducted a user study where we compared the routes reconstructed from the sequence of landmarks specified by the participants and their originally intended routes, and report some insight into possible aesthetic criteria in illustrating such maps.

Hsiang-Yun Wu, Sheung-Hung Poon, Shigeo Takahashi, Masatoshi Arikawa, Chun-Cheng Lin, Hsu-Chun Yen
Designing and annotating metro maps with loop lines
accepted for presentation in the 9th International Conference on Information Visualisation (iV2015), Barcelona (Spain), July 2015
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 noninterchange 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.

Rie Ishida, Shigeo Takahashi, Hsiang-Yun Wu
Interactively uncluttering node overlaps for network visualization
accepted for presentation in the 9th International Conference on Information Visualisation (iV2015), Barcelona (Spain), July 2015
Visual interaction with networks have been promising in the sense that we can successfully elucidate underlying relationships hidden behind complicated mutual relationships such as co-authorship networks, product copurchasing networks, and scale-free social networks. However, it is still burdensome to alleviate visual clutter arising from overlaps among node labels especially in such interactive environments as the networks become dense in terms of the topological connectivity. This paper presents a novel approach for dynamically rearranging the network layouts by incorporating centroidal Voronoi tessellation for better readability of node labels. Our idea is to smoothly transform the network layouts obtained through the conventional force-directed algorithm to that produced by the centroidal Voronoi tessellation to seek a plausible compromise between them. We also incorporated the Chebyshev distance metric into the centroidal Voronoi tessellation while adaptively adjusting the aspect ratios of the Voronoi cells so that we can place rectangular labels compactly over the network nodes. Finally, we applied the proposed approach to relatively large networks to demonstrate the feasibility of our formulation especially in interactive environments.

Norihide Kaneko, Reo Takahashi, Issei Fujishiro
Motion puppetry taking skeletal similarity into account
in Proceedings of The 28th International Conference on Computer Animation and Social Agents (CASA2015), NTU (Singapore), May 2015
Motion retargeting is a well-known method for generating character animations in computer graphics, where the original motion of an actor can be transferred to an avatar with a different skeletal structure and/or limbs’ length. A specific type of retargeting for manipulating various avatars interactively is referred to as puppetry. However, previous learning-based works of puppetry cannot be said to be fully interactive, or require a large amount of metadata about the avatar’s skeleton as well as training data of motions. Thus, we attempted to integrate existing methods by taking into account skeletal similarity between an actor and his/her avatar, to come up with an interactive and intuitive motion retargeting method that only requires a relatively small amount of training animations together with simple input metadata. Moreover, by classifying avatar’s body parts in a procedural manner, a more flexible motion puppetry was realized, where the system user is allowed to specify desirable part-to-part correspondences.

Kazuho Watanabe, Hsiang-Yun Wu, Yusuke Niibe, Shigeo Takahashi, Issei Fujishiro
Biclustering multivariate data for correlated subspace mining
in Proceedings of IEEE Pacific Visualization Symposium 2015, pp. 287-294, Hangzhou (China), April 2015
Exploring feature subspaces is one of promising approaches to analyzing and understanding the important patterns in multivariate data. If relying too much on effective enhancements in manual interventions, the associated results depend heavily on the knowledge and skills of users performing the data analysis. This paper presents a novel approach to extracting feature subspaces from multivariate data by incorporating biclustering techniques. The approach has been maximally automated in the sense that highly-correlated dimensions are automatically grouped to form subspaces, which effectively supports further exploration of them. A key idea behind our approach lies in a new mathematical formulation of asymmetric biclustering, by combining spherical k-means clustering for grouping highly-correlated dimensions, together with ordinary kmeans clustering for identifying subsets of data samples. Lower dimensional representations of data in feature subspaces are successfully visualized by parallel coordinate plot, where we project the data samples of correlated dimensions to one composite axis through dimensionality reduction schemes. Several experimental results of our data analysis together with discussions will be provided to assess the capability of our approach.

Kazuhide Ueda, Issei Fujishiro
Adsorptive SPH for directable bleeding simulation
14th ACM SIGGRAPH International Conference on Virtual Reality Continuum and its Applications in Industry, pp. 9-16, October 2015 [received Best Paper (First Prize) Award]
We build upon SPH to devise a directable scheme for bleeding simulation that realistically represents adherence onto and streak formation on the skin surface in real time. To ensure compatibility of expressiveness and space & time efficiency, we have judiciously designed four specific types of particles and their interactions and incorporated these elements into the SPH scheme. In-vivo particles obey a simple in-vivo blood flow model that can reflect both hemorrhage volume and blood pressure. The particles flowing out through the wound, called flow particles, manifest the primary behaviors of bleeding, including blood coagulation, blood adherence onto the skin surface, and streak formation on the skin surface. The scheme then involves transforming the flow particles adhered onto the skin surface into relatively small adhered particles and representing a thin, flat layer of adhered blood with anisotropic kernels. Guiding particles generated along user-input strokes play a distinct role in giving gravity, biased slightly by the guiding force, to the remaining flow particles and thereby allow the users to control the overall bleeding so that it follows the desirable traces.

Yuriko Takeshima, Issei Fujishiro
Ontology-supported design of visualization workflows in fluid science
in Proceedings of ACM SIGGRAPH Asia 2015 Symposium on Visualization in High Performance Computing, No. 2, November 2015
Modular visualization environments (MVEs) are commonly used in many disciplines including fluid science. However, it is difficult for scientists and engineers, who are not necessarily visualization experts, to make full use of many built-in modules on the basis of their usability and interdependency for constructing optimal visualization workflows. In this paper, we present a novel MVE, called goal-oriented application design guidance for modular visualization environments/flow visualization (GADGET/FV), that is designed and built on an ontological framework to assist users to design their flow visualization workflows. The system relies primarily on an extended Wehrend Matrix that allows users to specify their goals and requirements, and to search the knowledge-base for appropriate visualization workflows on their behalf. In addition, users can browse successful examples maintained in a case repository to facilitate their workflow design further; this concept is referred to as “design by example.” In this paper, examples of three practical fluid analyses have been presented to illustrate the usefulness of a prototype system. Furthermore, the extensibility of the system to handle large-scale datasets has also been discussed.

Ken Nagao, Yucong Ye, Chuan Wang, Issei Fujishiro, Kwan-Liu Ma
Enabling interactive scientifi c data visualization and analysis with see-through HMDs and a large tiled display
in Proceedings of VR2016 Workshop on Immersive Analytics, March 2015
Validation and exploration of the data generated by large-scale scientific simulations rely on sophisticated visualization and analysis tasks. With the advancement of supercomputing, the growing scale and complexity of the data make some of these tasks challenging, which demands new hardware and software solutions. We believe it is possible to address some of the challenges by utilizing the increasingly affordable see-through head mounted display (HMD) devices together with a low-cost tiled HDTV display. With the tiled display to provide a high-resolution overview of the data, the user can freely choose a small area to explore and analyze using a see-through HMD in stereoscopic 3D with gesture input. During such local exploration and detail data analysis, the user can apply a newly derived visualization parameter setting to the large tiled display for a new overview. In this way, computational costs become more manageable because realtime rendering and response are only required to cover a small screen space and a subset of the data. In our current study, we focus on supporting immersive isosurface and streamline visualization and analysis of 3D flow field data. In this workshop paper, we presented our preliminary design and results, and we also discussed our further development and evaluation plan.


Issei Fujishiro, Bing-Yu Chen, Wei Chen, Seok-Hee Hong, Takayuki Itoh, Koji Koyamada, Kenji Ono, Jorji Nonaka
Top computational visualization R&D problems 2015: Panel
in Proceedings of ACM SIGGRAPH Asia 2015 Symposium on Visualization in High Performance Computing, No. 20, November 2015
In this panel discussion, I want to share some opinions about the Data Visualization (or Information Visualization, i.e., InfoVis) without display and/or viewer to make the audiences think about some challenging cases while providing information to users. Some examples are also introduced, which probably may inspire some new directions for the research of Data Visualization as well as Information Visualization.


井阪 建, 藤代 一成
画像電子学会Visual Computing 情報処理学会グラフィクスとCAD合同シンポジウム(オーラル発表・査読付), DVD予稿集2015(15), 姫路市市民会館 (兵庫県), 2015年6月


Issei Fujishiro, Zhigeng Pan, Nadia Magnenat-Thalmann, Masaki Oshita, Nadia Magnenat-Thalmann, Xubo Yang, Hyun Seung Yang, Sptephen N. Spence
Proceedings of the 14th ACM SIGGRAPH International Conference on Virtual-Reality Continuum and its Applications in Industry, October 2015


Xiaoru Yuan, Baoquan Chen, Koji Komayama, Issei Fujishiro
Human-Centered Data Visualization: Guest editors’ Introduction
IEEE Computer Graphics and Applications, Vol. 35, No. 6, pp. 18-19, November/December 2015 [DOI: 10.1109/MCG.2015.132]

藤代 一成
ビジュアルコンピューティング特集号,画像電子学会誌,Vol. 44, No. 3, pp. 407-461, 2015年8月


藤代 一成
「ビジュアルコンピューティング分野ビジュアルコンピューティング(VC) 委員会」画像電子技術年報3-2-1
画像電子学会誌, Vol. 44, No. 2, pp. 208-209,2015年3月


菊池司, 篠原たかこ, 白石路雄, 新谷幹夫, 高橋時市郎, 竹内幸一, 名手久貴, 春口巌, 藤代 一成
映像表現・芸術科学フォーラム2015 報告
芸術科学会誌DiVA,38 号,pp. 8-13,2015年7月


Tetsuya Takahashi, Tomoyuki Nishita, Issei Fujishiro
Fast simulation of viscous fluids with elasticity and thermal conductivity using position-based dynamics
presented at Shape Modeling International 2015, June 2015

Shuzo John Shiota, Miho Aoki, Ricky Fong, Issei Fujishiro, Dallim Park, Loong Choon See
Education Panel: Tomorrow’s digital content leaders in Asia
in Proceedings of ACM SIGGRAPH Asia 2015 Symposium Education, No. 14, November 2015

Yusuke Niibe, Hsiang-Yun Wu, Kazuho Watanabe, Shigeo Takahashi, Issei Fujishiro
Making many-to-many parallel coordinate plots scalable by asymmetric biclustering
in Proceedings of the International Meeting on “High-Dimensional Data-Driven Science”, December 2015

Longyin Xu, Masanori Nakayama, Hsiang-Yun Wu, Makoto Uemura, Issei Fujishiro
Time-Tubes: Preliminary design of visualization tool for time-dependent, multi-variate blazar datasets
in Proceedings of the International Meeting on “High-Dimensional Data-Driven Science”, December 2015

清水文也, 藤代 一成
第78回情報処理学会全国大会, 1X-07 (講演論文集(4), pp. 125-126),2016年3月

神展彦芳賀直樹藤代 一成
第78回情報処理学会全国大会, 1Q-08 (講演論文集(2), pp. 444-445),2016年3月

堀井絵里藤代 一成
第78回情報処理学会全国大会, 5X-08 (講演論文集(4), pp. 193-194),2016年3月

早川雄登藤代 一成
第78回情報処理学会全国大会, 5X-04 (講演論文集(4), pp. 185-186),2016年3月

石川雄介, 藤代 一成
第78回情報処理学会全国大会, 5X-09 (講演論文集(4), pp. 195-196),2016年3月 学生奨励賞

清水貴大, 藤代 一成
第78回情報処理学会全国大会, 7W-02 (講演論文集(4), pp. 105-106),2016年3月 学生奨励賞

山本高美, 中山雅紀, 桂瑠以, 坂元章, 藤代 一成
3D ボディデータ分析に基づく身頃原型デザインシステムの開発
日本繊維製品消費科学会2015年年次大会研究発表要旨, p. 42, 2015年6月

植村誠, 前田啓一, Hsiang-Yun Wu, 渡辺一帆, 高橋成雄, 藤代 一成
バイクラスタリングの対話型可視化ツールを用いたIa 型超新星の分類
日本天文学会2015年秋季年会講演予稿集, No. K07a, 2015年9月

高橋玲央, 藤代 一成
セルルック3DCG のための輪郭線ベースアニメーション補間手法の提案
画像電子学会ビジュアルコンピューティングワークショップ2015, 2015年11月

Malik Olivier Boussejra, Noboru Adachi, Hideki Shojo, Ryohei Takahashi, Issei Fujishiro
LMML: Developing the Environment of the LMML Mark-up Language for Forensic Data Visualization
画像電子学会ビジュアルコンピューティングワークショップ2015, 2015年11月

Hsiang-Yun Wu, 渡辺一帆, 高橋成雄, 藤代一成
文部科学省科学研究費補助金新学術領域研究「スパースモデリングの深化と高次元データ駆動科学の創成」2015年度公開シンポジウム抄録集, pp. 37-46, 2016年3月

神展彦, 芳賀直樹, 藤代一成
映像表現・芸術科学フォーラム2016(映像情報メディア学会技術報告,Vol. 40, No. 11, pp. 1-4,AIT2016-42), 2016年3月 最優秀口頭発表賞(画像処理・感性)受賞

佐原淳允, 藤代一成
映像表現・芸術科学フォーラム2016(映像情報メディア学会技術報告, Vol. 40, No. 11, pp. 37-40, AIT2016-42), 2016年3月

村岡遼太, 藤代一成
映像表現・芸術科学フォーラム2016(映像情報メディア学会技術報告, Vol. 40, No. 11, pp. 89-92, AIT2016-42), 2016年3月 最優秀ポスタ賞(可視化・キャラクタアニメーション)受賞

鈴木涼平, 藤代一成
映像表現・芸術科学フォーラム2016(映像情報メディア学会技術報告, Vol. 40, No. 11, pp. 127-130, AIT2016-42), 2016年3月

小林杏理, 藤代一成
映像表現・芸術科学フォーラム2016(映像情報メディア学会技術報告, Vol. 40, No. 11, pp. 261-264, AIT2016-42), 2016年3月 優秀ポスタ賞(インタフェース)・CG-ARTS 人材育成企業賞(株式会社アニマ)受賞


Issei Fujishiro
Computational Journalism: Promising scenarios of big data visualization
Norrk’oping Visualization Center, Link’oping University, Norrk’oping, Sweden, October 2015

Issei Fujishiro
Computational Journalism: Promising scenarios of big data visualization
VIDI Labs, UC Davis, Davis, CA, USA, February 2015

データ可視化とスパースモデリング, データ駆動科学の地域展開
ミニ研究会宮崎大学工学部, 2015年9月

アーク情報システムSIGGRAPH2015報告会, 2015年10月


藤代一成, 井阪建
KEIO TECHNO{MALL 2015(第16 回慶應科学技術展), No. 14, 2015年12月