Accurate phase estimation is of prime importance in interferometric measurement techniques such as electronic speckle pattern interferometry, moiré interferometry and non-interferometric technique such as fringe projection profilometry. It is because the quantitative information of the measurand is directly proportional to the phase distribution obtained in these techniques. A spatial carrier fringe pattern analysis technique is proposed for the phase demodulation using the extended complex Kalman filter.

Fringe contrast variations are generated due to the use of different optical components, non-uniform illumination from light sources, unstable phase-shifter device and non-uniform reflectivity of the test sample. Consequently, obtaining an amplitude normalized fringe pattern is a desirable pre-processing operation in the phase demodulation process. A fringe pattern normalization algorithm is proposed using the smoothing Kalman filter.