 the compres- lines, and the factor 0.84 is the fraction of the horizontal sion system. Very high transmission bandwidth, scanning interval that is devoted to signal transmission. storage capacity, or quality requirements may The National Television Systems Committee (NTSC) necessitate lossless compression. Conversely, transmission standard used for television broadcasts in extremely low bit rate requirements may dictate the United States has the following parameter values, compression systems that trade-off image quality for FR = 29.97 fps a large compression ratio. Progressive transmission is NL = 525 lines a key issue for selection of the compression system. RH = 340 lines. It is generally used when the transmission bandwidth exceeds the compressed video bandwidth. Progres- sive coding refers to a multi-resolution, hierarchic, or This yields an analog video system bandwidth Bw of subband encoding of the video information. It allows 4.2 MHz for the NTSC broadcast system. In order to for transmission and reconstruction of each resolu- transmit a color digital video signal, the digital pixel tion independently from low to high resolution. format must be defined. The digital color pixel is made of Channel errors affect system performance and the three components: One luminance (Y) component quality of the reconstructed video. Channel errors occupying 8 bits, and two color difference components can affect the bit stream randomly or in burst (U and V) each requiring 8 bits. The NTSC picture fashion. The channel error characteristics can have frame has 720 X 480 X 2 total luminance and color different effects on different encoders, and can range pixels. In order to transmit this information for an NTSC from local to global anomalies. In general, transmis- broadcast system at 29.97 frames per second, the sion error correction codes (ECC) are used to miti- following bandwidth is required, gate the effect of channel errors, but awareness and Digital BW = 1/2 bitrate = 1/2(29.97 fps) knowledge of this issue is important.