An image denoising scheme based on wavelet packet and level dependent adaptive threshold is proposed in this paper. By using wavelet packet
the scheme not only decomposes the image into the low frequency part but also into the high frequency part of image so that the influence of noise can be eliminated. Meanwhile
using the level dependent adaptive threshold to process wavelet packet tree coefficient with soft threshold can keep edge information and important image information better since the soft threshold can clearly make the SNR of denoised image higher than general threshold. From the experiment results
we see that such scheme can not only suppress additive Gaussian white noise but also well keep original image information. The proposed method is useful for advanced image processing.