COMPOSITE VIDEO DECODING

摘要

Television uses a composite video signal to transmit color information. A color signal filter (12, 16) selects one of a plurality of candidate color signals derived from the composite video signal. The plurality comprises a first and second difference signal between the information for a central line and for lines on a first side and a second side of the central line respectively. The color signal filter promotes selection of the first difference signal over the second difference signal and vice versa according to whether the composite video signal represents an image with an edge on the second or first side of the central line respectively at the horizontal position. The apparatus contains circuitry (14) to detect a thin line configuration where data from the composite video signal for the central line is extreme relative to corresponding data for first and second lines on the first and second side respectively at the horizontal position. This circuitry (14) is coupled to the color signal filter (12, 16) to command selection of the information from the central line when the thin line configuration is detected.