Adaptive speckle reduction in SAR images combining directionlet transform with local texture direction
Ning Ma, Feng Ruan, Zeming Zhou, Peng Zhang · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2009
In this paper, according to the statistical characteristics of SAR images, we develop a new speckle reduction method based on directionlet transform by constructing a local texture-direction detector to adapt to the textural properties of the scene. Before despeckling, direction of texture is calculated according to the edge map. We take the standard deviation as the criterion while eight different directions arc considered. After directionlet transform, a Bayesian estimator is then applied to the decomposed data to estimate the best value for the noise-free coefficients. The denoising performance is among the state-of-the-art techniques based on standard wavelet transform.