APPARATUS FOR STANDARDS CONVERSION OF COLOUR TELEVISION SIGNALS

摘要

Demodulated luminance (Y) and chrominance (U, V) signals are stored in field stores 1 to m each with line outputs 1 to n. Output lines are formed by summing the producs of the line outputs with weighting coefficients which are specified for each line in the output standards. Separate sets of coefficients for luminance and chrominance are stored in respective memories. The chrominance sets are arranged to reduce the vertical and temporal resolution of the chrominance information. This has the beneficial effect of reducing cross-color interference. In the implementation shown the signals are stored as time multiplexed digital samples YYYUV (i.e. with one pair of chrominance samples to three luminance samples) and the luminance and chrominance coefficient sets for the current output line are stored as a11 to amn and b11 to bmn respectively in buffer registers. A switching waveform controls electronic switches to apply a11 to amn to multipliers when Y samples are presented and to apply b11 to bmn when U or V samples are presented.