The feasibility of correcting for failure of constant luminance in a colour television system

摘要

In a colour television transmission system such as the PAL system a constant-luminance failure is caused because the red, green and blue separation signals used to form the chrominance and luminance signals are not linearly related to the light outputs required from the red, green and blue display picture-tube phosphors.nAs a result, not all of the displayed luminance information travels via the luminance channel and the remainder, which travels via the chrominance channel, suffers a severe handwidth restriction. This report shows that it is possible, by modifying the coding process, to retain the otherwise lost information concerning fine detail associated with saturated colours by redirecting it to the luminance channel This results in a high-frequency boost of the luminance signal where there is fine detail associated with highly saturated colours in the picture. The resulting possibility of increased cross-colour, and the effect of the high-frequency boost on the monochrome picture are briefly discussed.