IMPORTANCE OF DWT IN DESPECKLING SAR IMAGES AND EXPERIMENTALLY ANALYZING THE WAVELET BASED THRESHOLDING TECHNIQUES

Speckle noise is a ‘granular pattern’ special kind of multiplicative noise mainly found in the SAR images and medical images such as CT scan and an ultrasound image. SAR is Synthetic Aperture Radar, special kind of radar that mainly captures the high-resolution images of the broad area of the earth surface. Image despeckling using wavelet transform is one efficient approach as it generates a large number of the small coefficients and a small number of the large coefficients. DWT is applied to analyze the speckled image more efficiently in detail. This paper gives a brief introduction to DWT and experimentally analysed the hard and soft thresholding functions. Matlab Toolbox Main Menu (MATLAB R2014a) is used to realize the practical implementation of thresholding functions and to obtain the experimental results.