Noise reduction by spatio-temporal filtering on parallel phase-shifting interferometry

Visualizing sound field is important to fully understand the acoustic behavior and phenomena. Recently, sound field visualization by using parallel phase-shifting interferometer (PPSI) has been proposed. PPSI can observe sound field quantitively and instantaneously without placing any object inside the field. However, the system has introduced some unwanted noise to the output fringe image. There is continuous development in signal processing method to reduce the noise in PPSI system. In this paper, different type of spatio-temporal filter has been tested to improve noise reduction in PPSI system upon establishing.