An image frame input unit receives the input of image frames. An insertion
unit inserts a plurality of markers into the image frame thus inputted.
Each of the plurality of markers is defined as a pattern that is not
scheduled to appear in data of the image frame. At this time, the
insertion unit divides the image frame into a plurality of parts based on
a data size storable in a radio packet, and inserts the markers among the
divided parts of the image frame. An RF unit outputs the image frame into
which the plurality of markers have been inserted.