PROBLEM TO BE SOLVED: To provide a mobile body tracking device that can track a tracking target without an erroneous detection even when a structure similar to the tracking target is present in the vicinity of the tracking target, in mobile body tracking, and to provide a radiation emission system.SOLUTION: A mobile body tracking control device 41 executes tone processing with respect to a filmed image A61 and a filmed image B62, measures a position of a marker 29 using the filmed image A61 and the filmed image B62 after execution of the tone processing and generates a signal for controlling emission of radiation based on the position of the marker 29.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT
