Abstract: In image recognition systems of the type employing a frame store having groups (N-tuples) of locations mapped to storage forming discriminators trained, or capable of being trained, to respond to different images, a problem arises in that either a large number of separate discriminator stores are required or recognition times are long. In the present invention the discriminator storage comprises p discrete stores having address terminals divided into two groups: one group directly mapped to respective portions of the frame store and the other group being connected in parallel and used to count through a number of N-tuple groups (each of size p) and/or a number of discriminators. Such a storage arrangement allows many different combinations of number of discriminator stores and recognition time, making possible an optimum combination for a particular application.