DPAD implements two different anisitropic diffusion based schemes for speckle filtering:
-SRAD (Speckle Reducing AD)
-DPAD (detail Preserving AD)
Both methods are based on an anisotropic extension of Frost's and Kuan's LMMSE filters for multiplicative noise. The goodness of the filter is based on a proper estimation of the Coefficient of variation of noise.
The diffusion can also be done using an AOS operator that implements the semi-implicit scheme.
Methods in the paper explained in:
Yu Y, Acton ST. Speckle reducing anisotropic diffusion. IEEE Trans Image Process. 2002;11(11):1260-70.
S. Aja‐Fernandez, C. Alberola Lopez, On the Estimation of the Coefficient of Variation for Anisotropic Diffusion Speckle Filtering, IEEE Trans. Image Processing, Vol.15, no. 9, sept 2006.
Toolbox based on the SRADDIF toolbox implemented by Yu and Acton (Based on "Nonlinear Diffusion Toolbox" by Frederico D'AlmeidaFile ID: #3710)