Method and apparatus for symbol recognition using multidimensional preprocessing

Data samples describing a plurality of micro-segments that compose a symbol to be recognized are received from a device such as an electronic pad. A preprocessor maps the micro-segments into cells of an array that has several feature dimensions. The preprocessor assigns values to the cells based on the length of a micro-segment associated with the cell, and how well the features of the associated micro-segment correspond to the feature label of the cell. The cell values are used as inputs to a neural network that identifies the symbol. In one embodiment, recognizing symbols from large groups of symbols is facilitated by using a plurality of neural networks. Each neural network is trained to recognize symbols from a different subgroup of symbols, and each neural network can determine whether the symbol belongs to its subgroup.