Abstract
We present a new model of a two-dimensional computing device called sgraffito automaton and demonstrate its significance. In general, the model is simple, allows a clear design of important computations and defines families exhibiting good properties.
It does not exceed the power of finite-state automata when working over one-dimensional inputs. On the other hand, it induces a family of picture languages that strictly includes REC and the deterministic variant recognizes languages in DREC as well as those accepted by four-way automata.