Global geometric, sound, and color controls for iconographic displays of scientific data

The authors introduce the Exvis exploratory data visualization system. This system uses a display technique based on visual texture perception to reveal structure in multidimensional data and includes a sound output facility for simultaneous sonification of data. The elementary unit of the display is a glyph, or 'icon,' whose attributes are data-driven. Global display controls for icon geometry, sound, and color have been added to the original system. A global control is a transformation that applies to the entire icon completely independently of the mapping of specific data parameters to specific icon attributes. These controls allow the user to maximize both the visual contrast and the auditory contrast available for a given choice of icon and a given mapping of data parameters to icon attributes, and they allow the user to selectively enhance different features in an iconographic display. Using these controls to manipulate displays of computer-generated multidimensional data, the authors have been able to obtain pictures that exhibit well-differentiated texture regions even though the data that produce these regions have no differences in their first-order statistics. The global display controls are most interactive when Exvis is implemented on a computing platform such as the Connection Machine, which can redraw an iconographic picture as rapidly as the user can manipulate the controls.