1. A system for generating a graph lattice from exemplary images, said system comprising: at least one processor programmed to: receive exemplary data graphs of the exemplary images, wherein nodes of the exemplary data graphs are formed from primitives; generate graph lattice nodes of size one from the primitives; until a termination condition is met, repeatedly: generate candidate graph lattice nodes from accepted graph lattice nodes, including the graph lattice nodes of size one and promoted graph lattice nodes, and the exemplary data graphs; select one or more candidate graph lattice nodes, the selected candidate graph lattice nodes preferentially discriminating exemplary data graphs which are less discriminable than other exemplary data graphs using the accepted graph lattice nodes; and, promote the selected graph lattice nodes to accepted status; wherein the graph lattice is formed from the accepted graph lattice nodes and relations between the accepted graph lattice nodes.