Patent US 5,459,523

An image transmission device is arranged to compress an image signal having a predetermined signal band by using a band compression circuit and to transmit the compressed image signal. The image transmission device is characterized by synthesizing a plurality of other image signals having a signal band narrower than that of the aforesaid image signal to approximately adapt the signal band of the other image signals to that of the aforesaid image signal and by selectively supplying one of the synthesized other image signals and the aforesaid image signal to the band compression circuit.