Gradient-based value mapping for pseudocolor images

bstract. We develop a method for automatic colorization of imges (or two-dimensional fields) in order to visualize pixel values nd their local differences. In many applications, local differences in ixel values are as important as their values. For example, in topogaphy, both elevation and slope often must be considered. Gradientased value mapping (GBVM) is a technique for colorizing pixels ased on value (e.g., intensity or elevation) and gradient (e.g., local ifferences or slope). The method maps pixel values to a color scale either gray-scale or pseudocolor) in a manner that emphasizes graients in the image while maintaining ordinal relationships of values. BVM is especially useful for high-precision data, in which the numer of possible values is large. Colorization with GBVM is demontrated with data from comprehensive two-dimensional gas chromaography (GCxGC), using both gray-scale and pseudocolor to isualize both small and large peaks, and with data from the Global and One-Kilometer Base Elevation (GLOBE) Project, using graycale to visualize features that are not visible in images produced ith popular value-mapping algorithms. © 2007 SPIE and S&T. DOI: 10.1117/1.2778426