Sony controls the problem on the vertical axis with Block Noise Reduction. Because the player knows where the block borders are, it identifies and suppresses block noise. A converters for interlace video. Their 10-bit converter operates at 27 MHz. So digital artifacts are minimized.
Gray scale is more accurate.
And picture gradations are closer to the original movie master. So you get beautiful rendition of colors and gray scale from the deepest black to the brightest highlights, providing a more natural film-like quality to DVD playback. The Super Sub Sampling Alias Filter acts like the digital filter in a CD player to process the video signal. It controls the noise of the alias signals. The result is lower video noise and cleaner fine image detail.