JPS605040B

PURPOSE:To extract and remove a specific pattern by one processing, by obtaining the peripheral distribution condition of each picture element position with the correlation degree to a collation mask pattern and determining the logical value of true picture element data from this data and data of each picture element data. CONSTITUTION:Peripheral picture element data j to s of picture element data i of an original pattern and collating mask pattern data a to h, which are so set previously that they may be matched to a pattern to be extracted or removed, are collated with each other for every corresponding picture elements in collating part 3-1. Then, coincidence signals of collating part 301 are counted by correlation counting part 302, and the counted value and correlation degree threshold N are compared with each other in comparing part 303. Further, logical signals outputted from comparing part 303 and picture element data i are subjected to logical calculation in a prescribed mode by operating parts 304 to 306, and this operation output is outputted as processing picture element data.