Asaduzzaman Babu and Mahmoud R. El-Sakka, "A Hybrid Scaling 
                  Factor for Speckle Reducing Anisotropic Diffusion", 
                  International Symposium on Image and Signal Processing and 
                  Analysis, ISPA'2013, pp. 4-9, September 2013, Trieste, Italy.
               
               
               
               Abstract
               
               
               
                  Classical Speckle Reducing Anisotropic Diffusion (SRAD) is a 
                  noise filtering method tailored to speckle reduction in 
                  digital images. It is well known that SRAD has a tendency to 
                  produce dislocated and un-sharp edges. This property of SRAD 
                  is highly attributed to its reliance on a homogeneous image 
                  region, selected initially, for a scaling factor calculation. 
                  Moreover, this scaling factor calculation strategy requires 
                  the interaction of an experienced user. To reduce the 
                  reliance on an initially selected perfect/near-perfect 
                  homogeneous region, we propose a hybrid scaling factor that 
                  reduces edge dislocation and preserves the sharpness of 
                  edges. The proposed scaling factor selection strategy uses a 
                  ratio-based edge detection technique for an estimation of 
                  the homogeneity of the initially selected region.