公开(公告)号：DE3381972D1

公开(公告)日：1990-12-06

申请号：DE3381972

申请日：1983-06-10

Applicant: IBM

Inventor： PENNEBAKER JR ,  PENNINGTON KEITH SAMUEL

IPC: G06T3/40 ,  G06T5/00 ,  G06T9/00 ,  H04N1/40 ,  H04N1/41 ,  H04N1/411

Abstract: A grey scale filter for image data is described which forces a least significant bit (1, 12) of a current pel equal to a most significant bit of the current pel when the most significant bit (m, 18) of the current pel is equal to the most significant bit of a previous (p, 16) and a next (n, 14) pel on a scan line of an image. The invention is embodied in a logic structure (20) employing exclusive ORs to make comparisons between the previous, next and current pels and logic gates to gate the value of the most significant bit of the most current pel to an output representing a filtered least significant bit of the current pel. It should be noted that the value of the most significant bit of the current pel (m, 18) is not changed since only changes between grey-white and white or grey-black and black are filtered by the present invention.