基于小波域的图像椒盐噪声密度估计

提出一种基于小波域的椒盐噪声密度估计方法.利用图像信号在小波域的系数具有稳定近似的分布,以及噪声对小波系数影响的特点,定量地分析了含噪图像的系数幅值直方图与原始图像的系数幅值直方图之间的偏离程度随噪声密度的变化规律,揭示这种变化关系对图像具有强的鲁棒性,从而利用这种关系对噪声进行估计.仿真结果表明,相对于目前方法,提出算法性能更佳,能够获得更准确的估计值和更小的估计偏差.

Estimation of salt-pepper noise in images in wavelet domain

A novel approach was proposed for estimating the density of salt-pepper noise in images using wavelet transform. On the basis of the fact that the wavelet coefficients of all natural images conform to stable and close distribution, as well as such distribution of the noisy image may be influenced by the noise, the proposed algorithm exhibits how the wavelet coefficients magnitude histogram of the noisy image deviates from that of original image along with the density of the salt-pepper noise in quantitative form, and indicates that the degree of such deviation is nearly determined by the noise density, i.e., the change relation is robust to image traits. The proposed algorithm thus takes advantage of this relation to make estimation. Compared with those of existing methods, simulation results show that the proposed approach has more exact estimation value and less deviation.