| 摘要 |
A still video image transceiver for use across narrow-band analog voice communication channels allows still video images captured or provided by a wide variety of consumer and industrial image sources, even those of the common hetrodyne-signal type, to be transmitted over a voice communication channel, such as over a telephone line or by high frequency radio communication. The captured video image is converted to an audio band signal using a digital linear signal processing method which avoids the common problem of first having to separate the image signal of its RGB color signal components. Use of a time-base corrector is avoided, while a jitter-free image for the receiver of the image is obtained even for those images which originate with asynchronous hetrodyne-type image source. Even over analog voice communication channels of marginal operating condition, an excellent signal to noise ratio is achieved because a limiter circuit is not used prior to demodulation of the received image signal. Also, a digital linear signal decoding method is used for superior results.
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