A wavelet threshold image denoising algorithm based on a new kind of sign function

Abstract

Based on the existing threshold denoising algorithm,a threshold denoising algorithm based on the new symbolic function was proposed.The new threshold function has advantages of continuous guidance,small deviation of wavelet coefficient,strong threshold adaptability and so on.It not only preserved the low-frequency wavelet coefficients,but also filtered the noise coefficients in the high-frequency coefficients effectively,so that the reconstructed image was closer to the original image.The simulation results of Bridge image,Lena image and B-mode Fetus image with Gaussian white noise show that the visual effect of both the new threshold function and the quantitative indicators PSNR and MSE are better than the existing threshold image denoising algorithm.The edge and detail information can be better protected,have no obvious oscillation,the image is smoother and even,and the method has good stubbornness under the background of complex noise.

Keywords

• sign function;wavelet threshold;denoising;robustness