基于脉冲耦合神经网络和图像熵的各向异性扩散模型研究  

Study of anisotropic diffusion model based on pulse coupled neural network and image entropy

作　　者：郭业才[1,2,3] 周林锋[1,2,3] 

机构地区：[1]南京信息工程大学、江苏省气象探测与信息处理重点实验室,南京210044 [2]南京信息工程大学、江苏省大气环境与姨各技术协同创新中心,南京210044 [3]南京信息工程大学电子与信息工程学院,南京210044

出　　处：《物理学报》2015年第19期132-142,共11页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11202106,61201444);教育部高等学校博士学科点专项科研基金(批准号:20123228120005);江苏省“信息与通信工程”优势学科建设项目;江苏省气象探测与信息处理重点实验室开放课题(批准号:KDXS1204,KDXS1403);江苏省青蓝工程;江苏省高校自然科学研究项目(批准号:13KJB170016)资助的课题~~

摘　　要：在图像去噪过程中,大部分基于偏微分方程的各向异性扩散模型均使用梯度信息检测边缘,当边缘部分被噪声严重污染时,这些方法不能有效检测出这些边缘,因而无法保留边缘特征.为了较完整的保留图像的区域信息,用脉冲耦合神经网络(PCNN)能使具有相似输入的神经元同时产生脉冲的性质对噪声图像做处理,得到图像熵序列,并将图像熵序列作为边缘检测算子引入到扩散方程中,不仅能克服仅用梯度作为边缘检测算子易受噪声影响的弊端,而且能较完整地保留图像的区域信息.然后,用最小交叉熵准则搜索使去噪前后图像信息量差异最小的阈值,设计最佳阈值控制扩散强度,建立基于脉冲耦合神经网络与图像熵改进的各向异性扩散模型(PCNN-IEAD).分析与仿真结果表明,该模型与经典模型相比,保留了更多的图像信息,能够兼顾去除图像的噪声和保护图像的边缘纹理等细节信息,较完整的保留了图像的区域信息,性能指标同样也证实了新模型的优越性.另外,该模型的运行时间较经典模型的短,因此,该模型是一个理想的模型.In image processing, most of the anisotropic diffusion models based on partial differential equation use gradient information to detect image edge. If the image edge is seriously polluted by noise, these methods would not be able to detect image edge, so the edge features cannot be retained. Pulse coupled neural network （PCNN） has the property that similar input neurons can generate pulse at the same time; this property is used to process the noisy image, and we can get an image entropy sequence. The image entropy sequence which will be used as an edge detecting operator is introduced into the diffusion equation, and this will not only reduce the defects produced when the gradient is used as an edge detecting operator so it is easily affected by the noise, but the area image information can also retain more completely. Then, we will use the rule of minimum cross entropy to search for a minimum threshold, which would satisfy the condition that the information difference between noisy image and denoised image is the minimum. The optimal threshold designed will control diffusion intensity reasonably, and the anisotropic diffusion model based on pulse coupled neural network and image entropy （PCNN-IEAD） can be established. Analysis and simulation results show that the proposed model preserves more image information than the classical ones. It removes the image noise and at the same time protects the edge texture details of the image; the proposed model retains the area image information more completely, the performance indexes can also confirm the superiority of the new model. In addition, the operating time of the proposed model is shorter than that of the classical models, therefore, the proposed model may be the ideal one.

关 键 词：图像去噪 脉冲耦合神经网络 图像熵 最小交叉熵 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]