In this paper we introduced new wavelet based algorithm for speckle reduction of synthetic aperture radar images, which uses combination of undecimated wavelet transformation, wiener filter (which is an adaptive filter) and mean filter. Further more instead of using existing thresholding techniques such as sure shrinkage, Bayesian shrinkage, universal thresholding, normal thresholding, visu thresholding, soft and hard thresholding, we use brute force thresholding, which iteratively run the whole algorithm for each possible candidate value of threshold and saves each result in array and finally selects the value for threshold that gives best possible results. That is why it is slow as compared to existing thresholding techniques but gives best results under the given algorithm for speckle reduction.<\/p>\r\n","references":"[1] Birgir Bjorn Saevarsson,Johannes R.Sveinsson and Jon Atli\r\nBenediktsson \"Combined Wavelet and Curvelet Denoising of SAR\r\nImages\" Proceedings of IEEE 2004.\r\n[2] Guozhong Chen,Xingzhao Liu \"Wavelet-Based Despeckling SAR\r\nImages Using Neighbouring Wavelet Cofficients.\" Proceedings of IEEE\r\n2005.\r\n[3] Guozhong Chen,Xingzhao Liu \"An Improved Wavelet-based Method\r\nfor SAR Images Denoising Using Data Fusion Technique\". Proceedings\r\nof IEEE 2006.\r\n[4] Mario Mastriani \"New Wavelet-based Superresolution Algorithm for\r\nSpeckle Reduction in SAR Images\" IJCS volume 1 number 4, 2006.\r\n[5] Guozhong Chen,Xingzhao Liu \"Wavelet-Based Despeckling SAR\r\nImages Using Neighbouring Wavelet Cofficients\" Proceedings of IEEE\r\n2005.\r\n[6] M.I.H.Bhuiyan,M Omair Ahmed \"Wavelet-Based Spatially Adaptive\r\nMethod for Despeckling SAR Images\". Proceedings of IEEE 2006.\r\n[7] Sheng Guofang, Hu Xin, Jiao Licheng \"SAR Image Denoising Based\r\non Data Fusion\" Proceedings of IEEE 2003.\r\n[8] Aglika Gyaourova \"Undecimated Wavelet Transforms for Image\r\nDenoising\" center for applied scientific computing, Lawrence Livermore\r\nnation laboratory, November 19,2002.\r\n[9] D.L .Donoho, \"Denoising by soft Thresholding,\" IEEE Trans Inform\r\nTheory,vol 41,pp.613-627,May 1995.\r\n[10] H.S. Tan. (2001, October). \"Denoising of\r\nNoise Speckle in Radar Image\"\r\n[11] H. Guo, J.E. Odegard, M. Lang, R.A. Gopinath, I. Selesnick, and\r\nC.S.Burrus, \"Speckle reduction via wavelet shrinkage with application\r\nto SAR based ATD\/R,\" Technical Report CML TR94-02, CML, Rice\r\nUniversity, Houston, 1994.\r\n[12] D. L. Donoho and I.M. Johnstone, \"Adapting to unknown smoothness\r\nvia wavelet shrinkage,\" Journal of the American Statistical Association,\r\nvol. 90, no. 432, pp. 1200-1224, 1995.\r\n[13] S.G. Chang, B. Yu, and M. Vetterli, \"Adaptive wavelet thresholding\r\nfor image denoising and compression,\" IEEE Transactions on Images\r\nProcessing, vol 9, no. 9, pp.1532-1546, september2000.\r\n[14] X.P.Zhang, \"Thresholding Neural Network for Adaptive Noise\r\nreduction,\" IEEE Transactions on Neural Networks, vol.12, no.3, pp567-\r\n584.May 2001.\r\n[15] Ren Lu ,Xing Mengdao,Bao Zheng,Chen Haojun \"Adaptive\r\nDespeckling SAR Images Based on Space Correlation\" Proceedings of\r\nIEEE 2005.\r\n[16] Siriporn Dachasilaruk,Yuttapong Rangsanser,Punya Thitimajshima\r\n\"Application of Multiscale Edge Detection to Speckle Reduction of SAR\r\nImages\".\r\n[17] Anil K. Jain, \"Fundamentals of Digital Image Processing\" pp.245-\r\n246,2004.","publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 7, 2007"}