22. The apparatus of claim 21, further comprising a consolidator that consolidates a set of equivalent classes by reducing the number of equivalent classes.
21. An apparatus for classifying symbols contained in binary encoded image data comprising: means for inputting electronic image data; means for extracting a run-length encoded representation of a symbol; means for determining a stroke width and symbol features of the extracted symbol from the run-length encoded representation; and a symbol classifier that classifies the extracted symbol into a first equivalent class if the extracted symbol matches an exemplar representing the first equivalent class and that creates a second equivalent class if the extracted symbol does not match the exemplar representing the first equivalent class, based on the stroke width and symbol features.