In a processor 10 of a wireless image transmission system 100 that transmits and receives, by radio communication, an image signal obtained by converting an image obtained by an endoscope apparatus 1, an error rate detection unit 15 monitors a communication state of radio communication. A color data editing unit 37 edits the image signal according to a diagnosis mode in which the endoscope apparatus 1 obtains an image when the deterioration of a communication state is detected by the error rate detection unit 15. An image transmission unit 14 transmits the image signal output from the color data editing unit 37 to a monitor 20.
