Browse Prior Art Database

Asynchronous Gray Tone Multiplex Transmission

IP.com Disclosure Number: IPCOM000090957D
Original Publication Date: 1969-Aug-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Stucki, P: AUTHOR

Abstract

This system can be used for the transmission of gray-tone pictures in which sudden amplitude change areas are only a small fraction of the total picture area. Since the channel capacity required for the transmission of a single picture is not fully used, multiplexing of several preprocessed pictures over the same channel is realized. The system achieves this by assigning, in each time slot, the transmission channel to that scanner encountering the maximum change of gray-level. The transmitter comprises an N x R maximum amplitude change detector matrix. Its rows are connected to N video scanners. Its columns, in number, correspond to the R sampling intervals. A concentrator or asynchronous multiplexer consists of a switch and an address coder.

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Asynchronous Gray Tone Multiplex Transmission

This system can be used for the transmission of gray-tone pictures in which sudden amplitude change areas are only a small fraction of the total picture area. Since the channel capacity required for the transmission of a single picture is not fully used, multiplexing of several preprocessed pictures over the same channel is realized. The system achieves this by assigning, in each time slot, the transmission channel to that scanner encountering the maximum change of gray- level. The transmitter comprises an N x R maximum amplitude change detector matrix. Its rows are connected to N video scanners. Its columns, in number, correspond to the R sampling intervals. A concentrator or asynchronous multiplexer consists of a switch and an address coder. While the incoming signals are passed through it one bit at a time, the matrix checks them against the signals received during the preceding R consecutive sampling intervals delayed by tau = 1/f. The matrix determines the scanner having the maximum amplitude change. The matrix also instantaneously causes the concentrator to connect this scanner to the transmission channel for address-coded transmission of the coded representation of the gray-level encountered. The word length per sample required for the information to be identifiable by the receiver is W = log
(N.Q), where Q is the number of amplitude quantization levels. The receiver consists of an expander or asynchronous demu...