Enhancement of Satellite Images Resolution Using Dual-Tree Complex Wavelet Transform

Abstract: Resolution enhancement(RE)methods that are independent of wavelets(interpolation methods) leads to blurring as high frequency components are lost.RE scheme based on Discrete wavelet transform(DWT) produces artifacts due to shift variant property.A complex wavelet-domain image resolution enhancement algorithm based on interpolation of the high-frequency subband images obtained by dual-tree complex wavelet transform (DT-CWT) is proposed.In this scheme, decomposition of the low resolution image into different subbands is done followed by the interpolation of the high frequency sub band images and the input image.This method uses forward and inverse dual-tree complex wavelet transform (DT-CWT) to generate the high-resolution (HR) image from the given low-resolution (LR) satellite input image. The HR image is reconstructed from the LR image by combining all these interpolated images using the inverse dual-tree complex wavelet transform (IDT-CWT). The quantitative peak signal-to-noise ratio (PSNR) and results are presented to reveal the superiority of the proposed technique through comparisons between state-of-the-art resolution enhancement methods.

Keywords: Resolution enhancement, image interpolation,shift variant, dual-tree complex wavelet transform, discrete wavelet transform, satellite image.