Fringe contrast enhancement using an interpolation technique

A fringe normalization process was presented to enhance the background illumination (a(x,y)) and the amplitude functions (b(x,y)) of the fringe image. To achieve it, two node lists containing the fringe peaks related to the local maximum and minimum irradiance of the fringe image. Then, two spline interpolation functions are calculated which fit each node list. These functions are used to interpolate each point in the fringe line. These process is repeated over each line in the fringe image.