Guest Editor's Introduction: Special Section on EuroVis

WE are very excited about the fact that extended versions of three outstanding papers from the Ninth Eurographics/IEEE VGTC Symposium on Visualization (EuroVis ’07) have been invited to this special section of IEEE Transactions on Visualization and Computer Graphics (TVCG). EuroVis ’07 took place in Norrköping, Sweden, from the 23rd to the 25th of May 2007 and it was in many ways a success. A record number of papers were submitted (93), of which 32 high quality full papers were selected by the committee based on nearly 500 reviews. A new attendance record of 125 participants was set. For the cochairs, it was a very challenging task to select among the many high quality papers the three papers to be presented in this special section. They are: 1) “Online Dynamic Graph Drawing,” 2) “Animation of Orthogonal Texture Patterns for Vector Field Visualization,” and 3) “Data-Driven Visualization and Group Analysis of Multichannel EEG Coherence with Functional Units.” The first paper by Yaniv Frishman and Ayellet Tal received the best paper award at the EuroVis ’07 for its high relevance to the field of graph drawing. The paper presents a solution to the difficult problem of real-time update of graphs that are changing on-the-fly. The challenge is to update a graph-layout while still making it easy for the user to comprehend the changes. Dynamic layout has been one of the major open problems in graph drawing, and this paper takes a significant step beyond previous work. The speed is gained via a clever implementation exploiting modern graphics hardware. The second paper by Sven Bachthaler and Daniel Weiskopf introduces animation of orthogonal vector field visualization on 2D manifolds. The authors generate a field that is orthogonal to the input vector field and use this field to create line patterns using line integral convolution. These line patterns are then animated to create the perception of the field motions. This novel idea is well founded in the perceptual aspects of animation in visualization and makes efficient use of the human capability of perceiving certain spatial frequencies in animations. In the third paper, Michael ten Caat, Natasha M. Maurits, and Jos B.T.M. Roerdink attack the problem of visual clutter in data driven high density EEG coherence analysis. The authors approach the problem by identifying functional units, sets of connected electrodes, and representing them in a Voronoi diagram preserving the spatial relation between electrodes while decluttering the view. The coherence between the functional units can then be displayed in the context of the diagram. The method presented is a new data driven alternative to the normal hypothesis driven EEG coherence analysis and it is based on insight into the clinical problem at hand and development of novel visualization techniques. We hope that you will enjoy reading these papers as much as we did and we would like to thank the authors for submitting their extended versions of their EuroVis ’07 papers. We would also like to thank the people who helped us make this special section of TVCG possible. In particular, we are thankful to Thomas Ertl, the Editor-in-Chief of TVCG. Last but not least, we would like to thank all the anonymous reviewers that helped us to select the three papers and the authors to improve the submissions for EuroVis ’07. IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS, VOL. 14, NO. 4, JULY/AUGUST 2008 1