Fixed pattern extracting apparatus, pattern writing apparatus, fixed pattern extracting method and recording medium

Abstract

In a computer, fixed pattern information indicating respective shapes of fixed pattern elements included in a fixed pattern and respective position vectors of the fixed pattern elements with respect to a reference position in the fixed pattern is prepared and key pattern elements coincident with any of fixed pattern elements are specified from writing pattern elements. Subsequently, a value is added to a position designated by a reverse vector of position vector of a corresponding fixed pattern element with each of the key pattern elements as a starting point in a setting area which corresponds to a writing pattern, and a position is specified to which a value coincident with the number of fixed pattern elements is given, to detect an existing position of the fixed pattern in the writing pattern. It is thereby possible in the computer to extract a fixed pattern from a writing pattern at high speed.