JPS6458181A - Binary differential signal correction circuit - Google Patents

Abstract

PURPOSE:To contrive to improve the accuracy of extracting a background picture elements by correcting a level of a difference signal being at a threshold value or below in the moving area in a retarded binarized differential signal before correction into a part over the threshold value while the retarded binarized differential signal before correction and the result of discrimination by an area discrimination means. CONSTITUTION:An area correction circuit 130 executes the correction processing to a retarded binarized differential signal before correction to be entered. An area discrimination circuit 150 discriminates it as a consecutive moving area block where picture elements whose binarized differential signal is significant '1' being the result of correction of picture elements whose binarized differential signal before correction is significant '1' are consecutive. Then the moving area block number for each scanning line and the block number of consecutive significant picture element '1' in the binarized differential signal in each block are counted and an area correction circuit 130 outputs the result as a form being referenced. However, '1' represents picture elements in the copy area. Thus, the moving part is extracted correctly even in a picture element with a small differential signal between frames.