Filtering out speckle noise is essential in many imaging applications. Speckle noise creates a grainy appearance that leads to the masking of diagnostically significant image features and consequent reduction in the accuracy of segmentation and pattern recognition algorithms. For low contrast images, speckle noise is multiplicative in nature. The approach suggested in this paper makes use of fourth order complex diffusion technique to perform homomorphic filtering for speckle noise reduction. Both quantitative and qualitative evaluation is carried out for different noise variances and found that the proposed approach out performs the existing methods in terms of root means square error (RMSE) value and peak signal to noise ratio (PSNR).
Jyothisha J. Nair and Govindan, V. K., “Speckle Noise Reduction Using Fourth Order Complex Diffusion Based Homomorphic Filter”, in Advances in Computing and Information Technology, Springer, 2012, pp. 895–903.