Different diets have been shown to leave characteristic patterns of microwear on the teeth of various mammalian species. The quantification of microwear features facilitates the comparison of taxa, and allows the discrimination of wear patterns associated with specific diets. The current study reports on a semiautomated image analysis procedure designed to expedite microwear quantification by engaging an IBM PS/2 running OS/2 Presentation Manager to compute and record the density, dimensions, and orientations of features defined by a user employing a mouse-driven cursor. This technique is used to distinguish microwear patterns on the maxillary central incisors (I1s) of four Sumatran primate species (n=5 per taxon) with known dietary differences (Hylobates lar, Macaca fascicularis, Pongo pygmaeus, and Presbytis thomasi). However, although developed for a particular problem area, the analytical routines described are of general interest.