Block noise detector and block noise eliminator

• Main Authors: OKUMURA NAOJI, TERAI KATSUMI, NIO YUTAKA, TANAKA KAZUHITO, OKAMOTO SATOSHI
• Format: Patent
• Language: English
• Published: 18.05.2004
• Edition: 7
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; IMAGE DATA PROCESSING OR GENERATION, IN GENERAL; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION

A vertical HPF and a horizontal HPF receive a video signal 101, and extract only a high frequency component in the vertical/horizontal directions, respectively. Absolute value taking parts take an absolute value of the high frequency components, respectively, and change their values to positive values. A horizontal accumulating/adding part and a vertical accumulating/adding part accumulate/add an input signal so as to output a vertical one-dimensional signal and a horizontal one-dimensional signal, respectively, each periodically having a peak value in the respective vertical and horizontal directions. A horizontal peak detecting part detects a horizontal peak position according to the horizontal one-dimensional signal. A vertical peak detecting part detects a vertical peak position according to the vertical one-dimensional signal and identifies a format thereof. A binarization part obtains a block boundary image, according to the horizontal peak position and the vertical peak position, in which pixel positions having a peak are provided with 1 and remaining pixel positions are provided with 0. In this manner, even if a block boundary to eliminate block noise thereon is not clearly identified, it becomes possible to correctly detect and eliminate the block boundary.