Wavelet transform based defringing in interference imaging spectrometer

The constructive and destructive fringe-like pattern (FP) introduced by the fringing effects is a universal phenomenon emerging in the imaging system using the back-illuminated CCD. Generally, the flat fielding or modeling based methods were applied to suppressing the FP and featured as time-consuming, duplicated, and hardware-based. In this paper, a method based on the wavelet transform was proposed for the interferogram processing in interference imaging spectrometer. An artificial interferogram construction method was developed and utilized to evaluate the quality of the reconstructed interferogram. The performance of defringing was significantly determined by the wavelet decomposition. Through numerical simulation, 4 wavelets were selected out of 50 typical wavelets; the decomposition levels with better performance were determined. The feasibility of the defringing and performance evaluation methods were verified by the simulation and practical experiments. It provides us with a software-based, time-saving, without prior knowledge, automatic approach for defringing.