| 摘要 |
<p>RUN LENGTH ENCODING AND DECODING METHODS AND MEANS Black and white run length encoding means first convert a binary video input signal having a raster scan format into binary black and white run length message codes which are preselected so that the initial or lead bit of each of those codes is at a given logic level. Ternary encoding means then convert the binary message codes into a series of ternary black and white run length message codes which have distinctive amplitude transitions at any intra-scan line code boundaries. To recover the video signal, the process is reversed. Moreover, a passband signal for transmitting the ternary codes from a transmitting terminal to a receiving terminal via a limited bandwidth communications channel may be provided by amplitude modulating a carrier frequency signal in accordance with the ternary codes.</p> |
