Patent ID: 6188799
Filing Date: 2001-02-13
Classification: H04N

Abstract:
A method for filtering a blocky noise from still and moving pictures, said method comprising:filtering the pictures in a vertical direction and a horizontal direction, filtering in each direction comprising:locating a block boundary in the picture and selecting pixels on one side of the block boundary as a first group and pixels on the other side of the block boundary as a second group;calculating mean values (m.sub.1, m.sub.2) and deviation (c.sub.1, c.sub.2) of the pixels in each of the first and second groups;detecting whether or not the deviations (c.sub.1, c.sub.2) are smaller than a predetermined threshold value (T.sub.2),applying a first predetermined filtering (equations (5), (6)) when the deviations (c.sub.1, c.sub.2) are not smaller than a predetermined threshold value (T.sub.2); andapplying a second predetermined filtering (equations (7), (8)) when the deviations (c.sub.1, c.sub.2) are smaller than a predetermined threshold value (T.sub.2).