The parameter selection is crucial to regularization based image restoration methods. Generally speaking, a spatially fixed parameter for regularization item in the whole image does not perform well for both edge and smooth areas. A larger parameter of regularization item reduces noise better in smooth areas but blurs edge regions, while a small parameter sharpens edge but causes residual noise. In this paper, an automated spatially adaptive regularization model, which combines the harmonic and TV models, is proposed for reconstruction of noisy and blurred images. In the proposed model, it detects the edges and then spatially adjusts the parameters of Tikhonov and TV regularization terms for each pixel according to the edge information. Accordingly, the edge information matrix will be also dynamically updated during the iterations. Computationally, the newly-established model is convex, which can be solved by the semi-proximal alternating direction method of multipliers (sPADMM) with a linear-rate convergence rate. Numerical simulation results demonstrate that the proposed model effectively reserves the image edges and eliminates the noise and blur at the same time. In comparison to state-of-the-art algorithms, it outperforms other methods in terms of PSNR, SSIM and visual quality.
翻译:参数选择对于基于正规化的图像恢复方法至关重要 。 一般来说, 整个图像中正规化项目的空间固定参数在边缘和平滑地区都表现不好。 更大型的正规化项目的参数在平滑地区会减少噪音, 但会模糊边缘区域, 而一个小参数会磨亮边缘, 但也会造成残余噪音。 在本文中, 提议了一个自动的空间适应性规范化模型, 将调音和电视模型结合起来, 用于重建噪音和模糊图像。 在拟议的模型中, 它检测边缘, 然后根据边缘信息对每个像素的Tikhonov和电视规范化参数进行空间调整。 因此, 边缘信息矩阵也会在迭代期间动态更新。 计算中, 新建的模型是 convex, 可以通过半份数交替法( SPADMMM) 和线性速率融合率来解决。 数值模拟结果显示, 拟议的模型有效保存图像边缘, 并消除了每个像素的噪音和模糊度。 在与状态的SISIM 和视觉质量中, 它的外形出其他方法。