Apparatus for detecting two-dimensional pattern and method for transforming the pattern into binary image

摘要

Two-dimensional pattern detecting apparatus provided with register for serially receiving binary signals obtained from analog signals of a two-dimensional pattern and adapted to divide the pattern into pixels and to represent the density of bright and dark for pixels by the binary signals. The apparatus further includes a processing circuit adapted to compare with predetermined patterns a pattern composed of 8 peripheral pixels of a partial area of 3x3 pixels within the two-dimensional pattern, on the basis of the binary signals stored in the register. The processing circuit outputs a binary signal of a logic value stored in said register corresponding to a central pixel of the partial area when the pattern of the 8 pixels coincides with one of said predetermined patterns, and to outputs a binary signal of a logic value prevailing in 8 binary signals stored in the register corresponding to the 8 pixels when the pattern of the 8 pixels does not coincide with any of the predetermined patterns.