1. Apparatus for recognising images, comprising an input store having a plurality of storage locations allowing data representative of elements of an image which is to be recognised to be stored at locations related to the positions of the elements, a plurality of output stores each having a number of address terminals which allow every storage location in that store to be addressed, the locations of the output store either containing, or being capable of containing, data related to images which are to be recognised, the address terminals being divided into at least a lower significance group and a higher significance group, each group of terminals containing at least one terminal, mapping means with input connected to the input store and a plurality of output terminals divided into groups with each group corresponding to a respective output store and at least one of the terminals of that group connected to an address terminal of the lower significance group of the corresponding store, addressing means connected to the terminals of the higher significance groups for cyclically addressing groups of storage locations, and discriminator means responsive to output signals from groups of output-store storage locations, when containing data and when addressed by way of the mapping means and by the addressing means during recognition, to provide a measure of recognition.