An automated system is provided for classifying materials in remotely-sensed imagery based on automated construction of a dynamic classifier—namely, a classifier that is automatically trained on the same image to which it is then subsequently applied. A first automated process identifies high confidence exemplars of each class using tailored classification techniques. This data is then used to train a supervised classification model (e.g., discriminant analysis), and the resultant classifier is applied to other pixels in the image that are unclassified or uncertain. Dynamic classification is automatically customized to the current image and can yield a more accurate and efficient material classification versus a static (image-independent) or manually trained classifier. It can overcome various confounding factors including inconsistencies in radiometric calibration, atmospheric conditions, and atmospheric distortions of ground spectra; different viewing and illumination geometries; and regional variations in the composition of certain materials like asphalt and concrete.