Method and apparatus for controlling image communication between a plurality of terminals and an exchange

DETAILED DESCRIPTION The present invention is a method and an apparatus which are useful for effectively performing image communication and is a method and an apparatus for composing a predetermined number of image signal to transmit the same through a single high-speed communication line.
First, a method for controlling image communication is described in a time sequential manner.
First, a terminal at the transmitting side carries out: (1) an image pick-up step for picking up an image of a given problem domain to enter image signal into the own terminal; and (2) a communication processing step for transmitting the image signal entered at the image pick-up step.
Next, an exchange network at the transmitting side carries out: (3) a composing step for composing the image signal transmitted from a predetermined number of terminals including said terminal at the transmitting side; (4) an encoding step for encoding the composite signal generated at the compositing step; and (5) a transmitting step for transmitting the composite signal encoded at the encoding step to the receiving side through the exchange.
In the exchange network at the receiving side a step included is a step of determining, in response to a call request from a certain terminal, whether the number of terminals under the communication state other than that terminal reaches a predetermined number.
If the number of terminals under the communication state is less than the predetermined number, it accepts the call request from said terminal and composes the image signal from said terminal and the image signal from the terminals under the communication state to transmit the same to the receiving side.
In this event, it includes a step of setting a call to the receiving side if there is no terminal under the communication state.
The exchange network at the receiving side carries out: (6) a decoding step for decoding the composite signal transmitted from the transmitting side; (7) a destination determining step for determining a destination of the respective image signal in the decoded composite signal in accordance with destination information transmitted with the composite signal; and (8) a transmitting step for transmitting the composite signal to the respective destination terminals determined at the destination determining step