摘要 |
A system is disclosed for the compatible transmission of a 16:9 progressive scan television signal by means of a letterbox formatted line interlaced signal. The letterbox edge bands contain a vertical helper signal representing the difference between a predicted progressive line and adjacent interlaced lines. Improved resolution of a progressive image at a progressive 16:9 receiver is facilitated by specially arranged half band filters in the transmitter/coder and inverse half band filtering in the receiver. Alternatively, when ordinary low pass filtering is used in the coder prior to interlaced subsampling, the fidelity of a reproduced image is improved using, an approximate simulation of such coder low pass filtering in the decoder together with a correction signal derived therefrom. An image reproduced at the progressive 16:9 receiver can more closely resemble the transmitter source signal by interative processing of the receiver correction signal.
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