1. A character-feature extraction device characterized in that boundary features of character patterns are broken down into a plurality of vectors and stored in a plurality of memory regions by vector direction wherein each vector is propagated into a respective direction with picture elements and wherein collisions among the vectors are detected via propagation processing, and wherein collision positions in each vector direction are extracted for the number of propagations to provide three-dimensional pattern features, which comprises: a motion-flag memory having regions each corresponding to the respective pattern for each vector direction; a stopping-flag memory having regions corresponding to the patterns for each vector direction; a means for converting the vector extraction positions on the patterns into flags according to their directions, and storing the flags in corresponding regions of the motion-flag memory; a means for moving flag values in the motion-flag memory via propagation processing into their respective vector directions; a means for reading the flag values sequentially from a first address to a final address in the motion-flag memory and in the stopping-flag memory after the propagation processing, and determining whether there are flag values representing the existence of vectors in the flag values of said addresses in the flag memory regions with other vectors having a phase difference of more than 90 degrees, and in addresses of the upper, lower, right, and left parts thereof; a means for resetting the flag values in said addresses in the region of the motion flag memory, and at the same time, setting the flags in said addresses in the regions of the stopping-flag memory with its vectors in the same direction, if there are vector flag values in said addresses of other flag memory regions; and a means for converting the flag values in each stopping-flag memory region and each motion-flag memory region into vector values via determination processing after propagation processing, and outputting the vector values as three-dimensional features.