In a processor of a wireless image transmission system that transmits, by radio communication, an image signal obtained by converting an image obtained by an endoscope apparatus, a communication state detection unit monitors a communication state of radio communication. An editing unit edits the image signal according to a mode in which the endoscope apparatus obtains an image when the deterioration of a communication state is detected by the communication state detection unit. A transmission unit transmits the image signal output from the editing unit to a receiver.