| 摘要 |
<p>The apparatus may be a digital TV receiver which displays the image for an auxiliary channel as an inset in the image for a main channel. The asynchronous composite video signals of the main and auxiliary channels are time division multiplexed (22, 24, 14) one line of auxiliary signal for every three lines of main signal. The chrominance and luminance components of the main channel signal are separated by an adaptive comb filter (40, 310). A low-pass filter (350) removes the luminance vertical detail components from the combed main channel chrominance and also separates the luminance components (YA) from the chrominance components for the auxiliary signal. The asynchronous time division multiplexed chrominance signals are processed by circuitry (380) which corrects the chrominance phase of each of the signals to be relative to a single reference phase and then separates the two quadrature modulated color difference signals. The auxiliary channel luminance and color difference signals are subsampled and stored in a memory (50) for display as an inset. The main channel samples are stored in a one-line memory (70) as they are written. Stored lines are displayed a second time, when auxiliary channel signals are being processed, to provide a continuous main channel image.</p> |
