Abstract: Based on the noise in the complex interferograms satisfying an additive noise model, a noise reduction scheme using wavelet packet soft thresholding method to respectively remove the noise in the real and imaginary part of the complex interferograms is proposed. A denoising experiment has been performed through a simulated SAR interferogram contaminated by noise, adopting Daubeachies wavelet as the base function of wavelet packet transform. It is shown that the noise reduction effect of three-level wavelet packet decomposition obviously outperforms that of one-level and two-level wavelet packet decomposition. Moreover, a denoising experiment result has been achieved using a practical interferogram including noise with the proposed scheme, and has been compared with that obtained by directly processing interferogram employing wavelet packet soft thresholding method. The experiment results demonstrated the validity of the scheme proposed by this paper.

Key words: wavelet packet transform, interferograms, denoising, soft thresholding