• Keerti Rai
• Avinash Rai
• Aafreen Alam

Recently, in many applications, Synthetic Aperture Radar (SAR) images play a very important role to visualize and observe scenarios. But, due to presence of speckle noise, SAR images are difficult to analyze as it degrades the quality of image and results in wrong interpretation. Speckle noise has characteristics of multiplicative noise. From last few years, researchers have focused their work for speckle noise reduction or despeckling. However, loss of edge information was observed in most of the existing works. Therefore, this paper is dedicated to design an algorithm for speckle reduction using benefits of wavelet transform and bivariate shrinkage functions. In the proposed algorithm first of all logarithmic transformation was performed to convert multiplicative noise to additive noise and further Lee filter is applied. Then filtered image was decomposed using wavelet transform. Further the bivariate shrinkage function was applied to estimate each coefficient and in last median filter was applied. The result analysis is performed on different test images and SAR images also. The result was evaluated on number of parameters such as Peak Signal to Noise Ratio (PSNR),Root Mean Square Error (RMSE), Structural Similarity (SSIM),Equivalent Number of Looks (ENL), Natural Image Quality Evaluator (NIQE) difference and time at different noise variance levels. The simulation result shows that the proposed algorithm outperforms better as compared to existing work and some conventional methods.

Additive White Gaussian Noise (AWGN), Bivariate Shrinkage, Discrete Wavelet Transform (DWT), Speckle Noise, Synthetic Aperture Radar (SAR),Wavelet Filter

"SPECKLE NOISE REDUCTION IN SAR IMAGES USING HYBRID WAVELET FILTER WITH BIVARIATE SHRINKAGE FUNCTIONS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.9, Issue 9, page no.86-95, September-2022, Available :http://www.jetir.org/papers/JETIRFS06016.pdf

"SPECKLE NOISE REDUCTION IN SAR IMAGES USING HYBRID WAVELET FILTER WITH BIVARIATE SHRINKAGE FUNCTIONS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.9, Issue 9, page no. pp86-95, September-2022, Available at : http://www.jetir.org/papers/JETIRFS06016.pdf