梯度自适应的图像复原方法

Gradient adaptive image restoration method

图像复原的方法有很多,这些方法所面临的主要困难是在抑制噪声时如何均匀地增强图像结构。本文介绍了一种基于图像梯度场进行图像复原处理的方法,该方法不像其他传统的方法直接操作图像的灰度,而是通过增强梯度场,在图像复原的同时,不会丢失图像的边缘信息。针对梯度对噪音非常敏感的特点,采用基于方向的各向同性滤波核方法,这可以抑制噪声区域,而同时又增强图像中的边缘部分。调整后的梯度场,通常是不可积的。通过求解泊松方程,便可以从修改过的梯度场重构复原图像。图像去噪实验说明该方法是有效的。

Various methods have been proposed for image restoration.The main difficulty is how to enhance the structures uniformly while suppressing the noise.This paper tackles this problem in the gradient domain instead of the traditional intensity domain.By enhancing the gradient field,this method can enhance the structure uniformly without overshooting at the boundary. Because the gradient field is very sensitive to noise,an orientation-isotropy adaptive filter is applied to the gradient field, suppressing the gradients in the noise regions while enhancing along the object boundaries.Thus a modulated gradient field is obtained,which is usually not integrable.The enhanced image can be reconstructed from the modulated gradient field with least square errors by solving a poisson equation.Experiments on noisy images show the efficiency of the method.