A method is disclosed for classifying an input pattern into an associated class
through use of a compound classifier. Data pertaining to preselected features present
within the input pattern are extracted. A discriminant value for each of a plurality
of classes is then determined via a first classification technique. This value
reflects the relative likelihood that a class is the associated class. The class
with the highest relative likelihood is selected. A confidence value is generated
via a second classification technique. This confidence value is reflective of the
a posteriori probability that the selected class is the associated class. The selected
class is rejected if the determined confidence value is below a predetermined threshold value.