Hi, Slightly out of topics, but I appreciate if you willing to explain. Thanks in advance. yuv 4:2:0, does it mean for every four sample of luminance we sample two U components and zero V components. while for yuv 4:4:4, and luminance and chrominance are sampled at same rate. I get confusion for yuv x:y:z with sampling rate for Y, Cr, Cb components. Any idea ? Thanks. Arthur. 2,000,000,000 Web Pages--you only need 1. Save time with My Lycos. http://my.lycos.com