PURPOSE: A motion recognition device and an operation recognition method using the same are provided to easily separate a motion trajectory, thereby removing a problem of inaccuracy of recognizing a user operation. CONSTITUTION: An input device(110) includes a light source(111) and an inertia sensor(113). A location change of the light source is detected during a user motion section determined from a sensing signal of the inertia sensor, a motion recognizing unit(120) extracts a user motion trajectory. A motion determining unit(121) calculates an energy variation amount from the sensing signal. The motion determining unit determines the user motion section according to an operation state of the user by comparing the calculated energy variation amount with at least one reference level.
Gesture cognitive device and method for recognizing gesture thereof