基于改进的四阶各向异性扩散的中值先验重建算法

Median Prior Reconstruction Algorithm Based on Fourth Order Anisotropic Diffusion

针对只能提供有限局部先验信息的最大后验法可以使重建后的图像出现阶梯状边缘伪影和过度平滑等缺点,提出了一种基于改进四阶各向异性扩散的中值先验重建算法.该算法首先在中值先验分布重建算法的目标函数中加入先验信息,用于保真图像的细节;然后针对重建图像依然存在块状伪影的问题,在每次迭代中对重建的图像进行改进的四阶偏微分降噪处理,从而使图像得到进一步的优化.仿真实验结果表明,该重建算法可以在对重建图像进行降噪的同时很好地保持图像的边缘和细节,获得高信噪比以及高质量的图像.

Median prior reconstruction algorithm based on fourth order anisotropic diffusion was put forward to solve the problems of the stepladder edge and over-smoothness of reconstructed image by maximum a posterior,which only could provide limited partial prior information.Firstly,the priori information was added to the objective function of the algorithm in the median prior distribution reconstruction algorithm for fidelity image details.Then,in view of the reconstruction image block artifact problems still existed,using improved fourth order partial differential noise reduction processing in each iteration for reconstruction of the image,which made further optimization of the image.The simulation experimental results show that the reconstruction algorithm can be in to carry on the noise reduction of the reconstruction image and good keep the edges and details of the image,obtaining high signal-to-noise ratio and high quality images.