Kamath, P.R.Senapati, K.Padikkal, P.2026-02-052021International Journal of Image and Graphics, 2021, 21, 2, pp. -2194678https://doi.org/10.1142/S0219467821500236https://idr.nitk.ac.in/handle/123456789/23282Speckles are inherent to SAR. They hide and undermine several relevant information contained in the SAR images. In this paper, a despeckling algorithm using the shrinkage of two-dimensional discrete orthonormal S-transform (2D-DOST) coefficients in the transform domain along with shock filter is proposed. Also, an attempt has been made as a post-processing step to preserve the edges and other details while removing the speckle. The proposed strategy involves decomposing the SAR image into low and high-frequency components and processing them separately. A shock filter is used to smooth out the small variations in low-frequency components, and the high-frequency components are treated with a shrinkage of 2D-DOST coefficients. The edges, for enhancement, are detected using a ratio-based edge detection algorithm. The proposed method is tested, verified, and compared with some well-known models on C-band and X-band SAR images. A detailed experimental analysis is illustrated. © 2021 World Scientific Publishing Company.Edge detectionMathematical transformationsShrinkageSignal filtering and predictionSpeckleSynthetic aperture radarDiscrete orthonormal S transformsEdge detection algorithmsExperimental analysisHigh frequency componentsLow and high frequenciesLow-frequency componentsSmall variationsTransform domainRadar imaging