1. A pattern recognition system for recognizing plural determined two-dimensional patterns located at different unknown positions within a larger two dimensional image area, said system comprising: means for the input of electronic data representing a two-dimensional area of digitized pixel areas, each of said pixel areas having a plurality of contiguous pixels corresponding to a portion of said image area which remains unsegmented with respect to the positions of the plural patterns included therewithin to be recognized; analysis means for analyzing successive potential character-occupying portions of said data associated with each of successive pixel areas of said unsegmented image area and for assigning to each of said pixel areas, in dependence on the corresponding said portion of data, a corresponding one label of a reference set of labels representing one of said predetermined patterns and a corresponding confidence measure indicating a degree of confidence in the assignment of said corresponding one label; buffer means for storing area values, said area value corresponding to a plurality of said successive overlapping pixel areas forming a two dimensional array of pixel areas, said area values comprising, for each of said neighboring pixel areas, positional information defining the position of the associated pixel area in said two dimensional image and said assigned label and a corresponding confidence measure assigned to the area by said analysis means, and decision means for outputting as electronic signals, labels and positional information corresponding to those pixel areas in said two dimensional array whose corresponding confidence measures indicate a confidence in the correctness of assignment of their corresponding labels which is in a predetermined relationship with that indicated by each of the confidence measures of other members of a two-dimensional overlapping sub-array of neighboring pixel areas within said two-dimensional array, the said relationship being such that the said labels and positional information correspond to those pixel areas whose confidence measures are maxima within each said two-dimensional sub-array.