本文提出了一种小波域平滑滤波的杂波抑制方法,该方法将原始图像变换到小波域后,分别对各小波子带先作平滑、后作差分处理以最大限度地滤除背景杂波和噪声,然后再对图像进行小波逆变换,达到有效抑制背景的目的.实验结果表明,该方法处理后得到的残差图像呈现出很好的高斯性和独立性,并且目标邻域信号杂波比(SC-NR)的平均增益比对图像直接平滑滤波的邻域信号杂波比(SCNR)的平均增益提高2dB左右,算法性能明显优于图像域平滑滤波的传统方法.
An image background clutter suppression method using smooth filter in the wavelet domain is proposed in this thesis.Firstly,the WT(Wavelet Transform)of the observed image data is performed.Then,the smooth filter and difference process is operated respectively to the wavelet coefficients of every wavelet belt to suppress background clutter and noise of the image.Finally,the IWT(Inverse Wavelet Transform) of the processed image is carried out.The experiment results show that the residual image obtained by this method has very good Gaussian normality and independence,and the average gain of the target's neighbor SCNR(signal-to-clutter-noise ratio) is improved about 2dB,compared with the other traditional image smooth-filtering algorithms.So the method in this paper has better performance than the other traditional image smooth methods.