To provide a wireless image transmission system including a digital FPU device, wirelessly transmitting image data resulting from processing a video signal from a camera by an image coder and receiving image data and outputting the image data to an image decoder, automatically matching the transmission rate of the image data with a transmission rate of the digital FPU device for simplifying rate settings.

Stuffing data equivalent to a difference between the clock rate of a clock signal received by a transmitter side digital FPU device and a transmission rate of the transmitter side digital FPU device are inserted periodically to image data, transmission data to which header information denoting an interval of the stuffing data and clock rate information denoting a data rate of the image data before insertion of the stuffing data are added are transmitted to a receiver side digital FPU device, and the receiver side digital FPU device detects the header information from the transmission data to eliminate the stuffing data, so as to recover the image data and the clock signal on the basis of the clock rate information.