The application of scene synthesis techniques to the display of multidimensional image data

Reviewer: Robert L Cannon

This paper presents a technique for interpreting multidimensional data by viewing the spatial superposition of one data set upon the other. The authors suggest that when the two data sets have different underlying spatial structures, then a two-color display (say red and green) may not result in a representation which is easy for the viewer to understand. In the technique presented here, the authors model one of the two data sets as a surface, using shaded-relief techniques to display the topography with a single color. The other data set is represented in one of two ways, either by coloring the surface representing the first data set, or by overlaying a colored transparency upon the surface representing the first data set. Color illustrations depict the differences in the results which are derived from the two-color technique, as well as those proposed by the authors. For a contour map of an area and a map of magnetic field strength, the authors present color photographs depicting the various techniques of data representation. Their approach does indeed present the two data sets such that the magnetic field strength data appear to be overlaid upon a contour map. To this reviewer, a geologist could find more information in the resulting image than in a traditional two-color representation. The great difficulty of the technique, however, is that it is extremely complex. Models of surface reflection and pigmentation are computationally complex, as well as difficult for persons untrained in computer graphics to comprehend. It will be quite difficult for, say, a geologist unfamiliar with computer graphics and color theory to implement these techniques without reference to a number of other texts and papers (or perhaps a colleague who works in the area). Nevertheless, when a simple two-color display of data from two data sets does not yield useful information, this approach may be of great value.