Based on the characteristic of striping noise in TDI-CCD images, a new destriping noise technique which combines FFT with wavelet transform to search the frequency point of the striping noise is presented. The improved notch filter is selected to eliminate the striping noise. In addition, an improved threshold function based on lifting wavelet transform is used to eliminate the stripes. Experiment shows that the method of improved notch filter is superior to the improved threshold function while the improved threshold function is superior to the hard and the soft threshold function. After destriping using the improved notch filter, the quality of image is enhanced. The PSNR of the destriping image processed by improved notch filter is increased to 46.4181dB and the NMSE is decreased to 0.00007. Compared to the methods of threshold function based on lifting wavelet transform, the PSNR of destriped image is improved by 3～4dB and the NMSE is reduced by 0.00007～0.00011. The method of improved notch filter which combined FFT with wavelet transform and the methods of threshold function based on lifting wavelet transform can eliminate the striping noise while preserve the characteristic of the original image, so the several methods are of feasibility.
DownLoad: