1. A machine for automatically classifying graphical input patterns, comprising: a) a memory for storing digital representations of the input patterns; b) a feature calculator for calculating one or more single-valued functions of a current input pattern and storing the result of said calculation as an array to be referred to as a test map; and c) a data processor for (i) comparing at least a portion of the test map to each of a plurality of data arrays, each array of said plurality representing a particular one of plural classes to which a given input pattern may be assigned, and responsive to said comparison, (ii) assigning the current input pattern to one of said classes; wherein the feature calculator comprises: d) a library of line segments constructed in a representational space for input patterns, each said line segment subdivided into plural indexed sub-intervals; and e) a data processor for (i) projecting the current input pattern onto each line segment in said library, and (ii) storing in the test map of said pattern the index of each sub-interval onto which said pattern is projected.