Double density wavelet transformation for speckle reduction of SAR images
IEEE International Geoscience and Remote Sensing Symposium - Tập 1 - Trang 113-115 vol.1
Tóm tắt
Discrete wavelet transformations (DWTs) based on oversampled filter banks, proposed by I. W. Selesnick (2001), are used for speckle reduction of SAR images. The oversampled DWT is called double density DWT (DD-DWT) and is based on a single scaling function (lowpass) and two distinct wavelet functions (highpass). The DD-DWT is useful for speckle reduction through its subband images and the speckle reduction is obtained by thresholding the subband-image coefficients of the digitized SAR images. A thresholding method using non-linear functions which are adapted for each selected subband is used in the paper. The non-linear functions are based on sigmoid functions. The denoising method shows great promise for speckle removal and hence can provide good detection performance for SAR based recognition.
Từ khóa
#Speckle #Discrete wavelet transforms #Wavelet coefficients #Noise reduction #Filter bank #Additive noise #Cost function #Electronic mail #Chaos #Gaussian noiseTài liệu tham khảo
10.1109/IGARSS.1996.516245
10.1109/78.485919
10.1109/TPAMI.1980.4766994
selesnick, 2001, The Double Density DWT, Wavelets in Signal and Image Analysis From Theory to Practice, 10.1007/978-94-015-9715-9_2