Browsing by Author "Ware, Colin"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Designing Pairs of Colormaps for Visualizing Bivariate Scalar Fields
    (The Eurographics Association, 2020) Ware, Colin; Samsel, Francesca; Rogers, David H.; Navratil, Paul; Mohammed, Ayat; Kerren, Andreas and Garth, Christoph and Marai, G. Elisabeta
    In scientific visualization there is sometimes a requirement for two colormaps to be used to represent two co-registered scalar fields. One solution is to represent one of the fields as a continuous colormapped image, and the second field by means of a dense distribution of small glyphs overlaid on the background image and coded using a different colormap. This requires the design of pairs of colormaps which each can be easily read, but which minimally interfere with one another. Colormap pairs separated according to lightness, saturation and hue, were designed and evaluated using both a key accuracy task and a pattern identification task. The saturation separation pair (one colormap having high saturation and the other low saturation) was the best overall.
  • Thumbnail Image
    Item
    Evaluating Countable Texture Elements to Represent Bathymetric Uncertainty
    (The Eurographics Association, 2022) Ware, Colin; Kastrisios, Christos; Agus, Marco; Aigner, Wolfgang; Hoellt, Thomas
    Measurements of the depth of the seabed vary widely in both horizontal and vertical accuracy. To convey this information to mariners, Zones of Confidence (ZOC) are defined for charts. A mosaic of ZOCs can be represented as a chart overlay. This study evaluates two novel designs for textures to represent ZOCs. Both use textures with countable elements to represent different ZOC levels. One uses a texture made of lines where the number of lines in a texture cell represents the confidence level; the other uses dot clusters where the number of dots similarly represents the ZOC level. In the study, these were compared with three alternatives that used color to respond and accuracy as dependent variables. The dot clusters design yielded the fastest responses overall. A method using levels of color transparency proved to be the slowest and least accurate.
  • Thumbnail Image
    Item
    Hairy Slices II: Depth Cues for Visualizing 3D Streamlines Through Cutting Planes
    (The Eurographics Association and John Wiley & Sons Ltd., 2020) Stevens, Andrew H.; Ware, Colin; Butkiewicz, Thomas; Rogers, David; Abram, Greg; Viola, Ivan and Gleicher, Michael and Landesberger von Antburg, Tatiana
    Visualizing 3D vector fields is challenging because of occlusion problems and the difficulty of providing depth cues that adequately support the perception of direction of flow lines in 3D space. One of the depth cues that has proven most valuable for the perception of other kinds of 3D data, notably 3D networks and 3D point clouds, is structure-from-motion (also called the Kinetic Depth Effect); another powerful depth cue is stereoscopic viewing. We carried out an experiment of the perception of direction for short streamlines passing through a cutting plane. The conditions included viewing with and without structurefrom- motion and with and without stereoscopic depth. Conditions also include comparing streamtubes to lines. The results show that for this particular task, stereo provided an effective depth cue, but structure-from-motion did not. Ringed streamtubes and streamcones provided good 3D direction information, even without stereoscopic viewing. We conclude with guidelines for viewing slices through vector fields.