Compression of complex SAR images using directional lifting wavelet transform

Abstract

In this paper, directional lifting wavelet transform (DLWT) is innovatively used in the compression of complex synthetic aperture radar (SAR) images. As real-part and imaginary-part of the complex SAR image are rich in edges, two complex SAR image coding algorithms using DLWT, i.e. DLWT IQ and DLWT FFT are proposed. DLWT IQ separately applies DLWT and bit plane encoding on the real-part and imaginary-part. DLWTFFT applies DLWT and bit plane encoding on the real image converted from complex SAR image with fast Fourier transform (FFT). Compared with the coding algorithms using discrete wavelet translation (DWT), DLWT IQ and DLWT FFT perform better amplitude peak signal to noise ratio (PSNR) and mean phase error (MPE) than coding algorithm using DWT. Through comparison of the two algorithms using DLWT, DLWTFFT's coding performance is better. In addition, DLWTFFT also shows superior amplitude and phase fidelity to the frequency-domain algorithm.