Aligning the frames of a non stationary imaging Fourier transform spectrometer for spectrum retrieval
This paper presents an algorithm to align the frames obtained with a non-stationary imaging Fourier transform spectrometer (IFTS). These frames contain both relative motion and intensity variation due to the interference pattern of the IFTS called interferogram. Two motion estimation techniques are combined to register the frames with a sub-pixel precision. An approach based on mutual information is first used for pixel-precision registration with respect to a single reference frame. Sub-pixel precision is then achieved using a phase-based technique.