Patent ID: 6975777
Filing Date: 2005-12-13
Classification: H04N

Abstract:
1. An apparatus for detecting a block noise generated on an input video signal that has been coded and decoded per pixel block, the apparatus comprising: a differentiator to differentiate the input video signal per pixel to obtain a differentiated signal; a detector to detect impulses of the differentiated signal to obtain a detection signal carrying the impulses; an integrator to integrate the detection signal for every N-th pixel of consecutive M pixels in a horizontal direction and to obtain integrated detection signals corresponding to a first to an M-th pixels, respectively, M being the number of pixels per pixel block in the horizontal direction, and N being an integer among 1 to M; and a determinator to compare the integrated detection signals and a reference signal to determine whether the block noise is generated on the input video signal, wherein the determinator includes: a counter to count the number of integrated impulses of the integrated detection signal per predetermined unit of image carried by the input video signal; a plurality of delay sections each delaying the counted number by a period decided based on the predetermined unit of image, thus outputting count signals for succeeding images in the predetermined unit of image; and a median section to select a middle count signal among the count signals, which is the middle in level, the middle count signal being compared with the reference signal.