Television transmission system

A high definition color television transmission system comprising means for dividing wide band luminance information into a first luminance portion containing lower frequency components of said luminance information and a second luminance portion containing higher frequency components of said luminance information, means for transmitting said first luminance portion by way of a first transmission path, means for frequency shifting said second luminance portion such that the resulting frequency-shifted second luminance portion lies within the bandwidth of a second transmission path which bandwidth is substantially equal to that of the first transmission path, and means for transmitting the frequency-shifted second luminance portion by way of the second transmission path, characterized in that said first luminance portion has a bandwidth which is narrower than that of said second luminance portion, while a color subcarrier modulated by color information is also transmitted by way of said first transmission path, the color subcarrier being located outside the bandwidth of said first luminance portion but within the bandwidth of said first transmission path, the system being such that the transmissions from the first and second transmission paths may be received together and the first and second luminance portions of the luminance information recombined for reproduction as a high definition color television display or the transmission from the first transmission path may be received alone for reproduction as a color television display of acceptable quality.