A method for generating codes for a code mask is provided. A plurality of symbols may be arranged into an n1 by n2 symbol structure, where n1 and n2 are integer values. A plurality of codewords may be defined from different overlapping k1 by k2 windows within the symbol structure, wherein co-linear and spatially overlapping windows define unique codewords, and the codewords are unique in a first direction of the symbol structure but are repeated in a second direction that is perpendicular to the first direction. A plurality of the symbol structures as a code mask, wherein symbols in two adjacent k1 by k2 windows are selected so as to avoid codeword aliasing of codewords in the two adjacent k1 by k2 windows.