一种嵌入局部信息的快速KFCM聚类分割算法

针对核空间模糊局部C-均值聚类分割算法时间复杂性过大而不适合实时场合图像分割需要的问题,提出了一种核空间局部模糊C-均值聚类分割的快速算法。利用像素与其邻域像素之间的空间距离信息和灰度方差信息构造一种加权共生矩阵;将图像像素的一维直方图以及像素与邻域像素之间的二维共生直方图相结合构造了一种新的核空间模糊C-均值聚类分割目标函数,并对其推导获得隶属度和聚类中心迭代表达式;将图像像素采用该算法聚类所得隶属度进行邻域滤波处理,以便改善该算法的抗噪性能。实验结果表明,该分割算法相比核空间局部模糊C-均值聚类分割更有利于实时场合和大幅面图像分割的需要。     

基于捕食者—食饵微粒群优化的二维FCM图像分割方法

传统模糊C均值聚类算法进行图像分割时仅利用了像素的灰度信息,没有考虑像素的空间邻域信息,因此抗噪性能差．为了克服传统模糊C均值聚类算法的局限性,提出了一种基于捕食者—食饵微粒群算法的二维模糊C均值聚类图像分割方法．该方法将图像的聚类分割转化为一个优化问题,根据像素的灰度信息和改进二维直方图描述的像素邻域关系特性,建立包含邻域信息的适应度函数,并利用捕食者—食饵微粒群的全局优化能力,通过迭代优化获得最优聚类中心,实现图像分割．仿真结果表明,所提算法不易陷入局部最优,抗噪能力强,聚类正确性高,分割效果好,是一种有效的图像分割算法．     

快速鲁棒核空间模糊聚类分割

目的 传统模糊C-均值聚类应用于图像分割仅考虑像素本身的聚类问题,无法克服噪声干扰对图像分割结果的影响,不利于受到噪声干扰的工业图像、医学影像和高分遥感影像等进行目标提取、识别和解译。嵌入像素空间邻域信息或局部信息的鲁棒模糊C-均值聚类分割算法是近年来图像分割理论研究中的热点课题。为此,针对现有的鲁棒核空间模糊聚类算法非常耗时且抑制噪声能力弱、不适合强噪声干扰下大幅面图像快速分割等问题,提出一种快速鲁棒核空间模糊聚类分割算法。方法 利用待分割图像中像素邻域的灰度信息和空间位置等信息构建线性加权滤波图像,对其进行鲁棒核空间模糊聚类。为了进一步提高算法实时性,引入当前聚类像素与其邻域像素均值所对应的2维直方图信息,构造一种基于2维直方图的鲁棒核空间模糊聚类快速分割最优化数学模型,采用拉格朗日乘子法获得图像分割的像素聚类迭代表达式。结果 对大幅面图像添加一定强度的高斯、椒盐以及混合噪声,以及未加噪标准图像的分割测试结果表明,本文算法比基于邻域空间约束的核模糊C-均值聚类等算法的峰值信噪比至少提高1.5 dB,误分率降低约5%,聚类性能评价的划分系数提高约10%,运行速度比核模糊C-均值聚类和基于邻域空间约束的鲁棒核模糊C-均值聚类算法至少提高30%,与1维直方图核空间模糊C-均值聚类算法具有相当的时间开销,所得分割结果具有较好的主观视觉效果。结论 通过理论分析和实验验证,本文算法相比现有空间邻域信息约束的鲁棒核空间模糊聚类等算法具有更强的抗噪鲁棒性、更优的分割性能和实时性,对大幅面遥感、医学等影像快速解译具有积极的促进作用,能更好地满足实时性要求较高场合的图像分割需要。     

一种快速鲁棒核空间图形模糊聚类分割算法

针对现有鲁棒图形模糊聚类算法难以满足强噪声干扰下大幅面图像快速分割的需要，提出一种快速鲁棒核空间图形模糊聚类分割算法。该算法将欧氏空间样本通过核函数映射至高维空间；采用待分割图像中像素邻域的灰度和空间等信息构建线性加权滤波图像，对其进行鲁棒核空间图形模糊聚类；并引入当前聚类像素与其邻域像素均值所对应的二维直方图信息，获得鲁棒核空间图形模糊聚类快速迭代表达式。对大幅面图像添加高斯和椒盐噪声进行分割测试，实验结果表明:本文算法相比基于图形模糊聚类等分割算法的分割性能、抗噪鲁棒性和实时性有了显著提高。     

优选抑制式非局部空间模糊C-均值图像分割方法

当图像被噪声严重污染时,像素的邻域像素也可能被污染。此时,来自于像素点的邻域像素的局部空间信息无法在含噪图像分割中发挥积极的指导作用。鉴于此,利用图像中与像素具有相似邻域结构的像素构造新的非局部加权和图像,并在新图像的灰度直方图上采用优选抑制式模糊C-均值聚类,提出优选抑制式非局部空间模糊C-均值图像分割方法。实验结果表明,该方法能进一步提高模糊C-均值聚类方法对于图像噪声的鲁棒性,获得了更加理想的分割结果。     

基于空间邻域加权的模糊C-均值聚类及其应用研究*

针对模糊C-均值聚类法用于图像聚类时仅利用了像素的灰度信息,而忽视空间位置信息,导致在噪声区域和边界处有误分类现象,提出一种新的基于空间邻域加权的模糊C-均值图像聚类法。首先,定义了一个空间邻域信息函数,该函数能够有力抑制噪声点,同时能够很好保留边界的特性;其次,设计了具有空间约束的样本邻域信息加权隶属度矩阵;最后,将该方法应用于人工合成图像和模拟MR脑图像的聚类。实验结果表明,该方法能够获得较好的聚类效果,同时具有较强的抑制噪声的能力。     

结合小波变换和改进邻域权值的FCM算法

针对改进的模糊C均值聚类算法在进行图像分割时构建的邻域权值函数未能同时考虑空间结构信息和灰度值域信息,而导致对噪声敏感及边缘纹理信息的处理粗糙的问题,提出了一种结合小波变换和改进邻域权值的FCM算法.该算法首先在原始灰度图像的基础上进行小波多分辨率分析的自适应阈值去噪处理;然后在重构图像上结合双边滤波的思想构建一个基于图像块局部空间邻域信息和灰度值域信息的改进邻域权值函数.实验结果表明,该算法比传统FCM算法以及FCM的改进算法有更高的分割精确度,对强噪声更具鲁棒性,图像边缘也更加平整.     

基于快速二维熵的加权模糊C均值聚类图像分割

提出了一种结合快速二维熵和加权模糊C均值聚类的图像分割方法。采用快速二维熵算法对实际图像进行初步分割求得目标和背景的中心,然后采用样本点像素与其邻域灰度像素的差别表征该样本点对分类的影响程度,最后利用加权模糊C均值聚类算法完成图像分割。该方法一方面解决了传统的模糊C均值聚类算法对初始值敏感的问题,另一方面克服了传统的聚类算法对数据集进行等划分的缺陷。实验结果表明,该方法不仅具有良好的收敛性,而且还可以有效地把目标从背景中分割出来,具有重要的实际应用价值。     

结合空间信息的模糊C均值聚类图像分割算法

提出一种结合空间信息的模糊C均值聚类图像分割算法.该方法将图像的二维直方图引入传统的模糊C均值聚类算法,并对隶属函数做了改进;依据平方误差和最小准则,来确定模糊分类矩阵及聚类中心;最后,依据最大隶属度原则,划分图像像素的类别归属.实验结果表明,该方法能快速有效地分割图像,并且具有较强的抗噪能力.     

各向异性权重的模糊C均值聚类图像分割

传统的模糊C均值聚类算法(FCM)在图像分割中未考虑各个点的灰度特征及其邻域像素的关联程度,导致其对于噪声十分敏感.而各种改进算法虽然较好地克服了图像噪声的影响,但由于使用均值滤波等方法导致分割图像边缘模糊.为此,提出一种基于各向异性权重的FCM图像分割方法,通过引入新的邻域窗口权重的计算方法,使得中心点邻域内各点具有各向异性的权重;并使用基于灰度级的快速算法,提出了各向异性权重的模糊C均值聚类算法.实验结果表明,文中方法具有较强的抗噪性,对于噪声具有良好的稳定性,分割精度较高.     

结合类内和类间距离的可能聚类分割算法

目的 为了进一步提高噪声图像分割的抗噪性和准确性,提出一种结合类内距离和类间距离的改进可能聚类算法并将其应用于图像分割。方法 该算法避免了传统可能性聚类分割算法中仅仅考虑以样本点到聚类中心的距离作为算法的测度,将类内距离与类间距离相结合作为算法的新测度,即考虑了类内紧密程度又考虑了类间离散程度,以便对不同的聚类结构有较强的稳定性和更好的抗噪能力,并且将直方图融入可能模糊聚类分割算法中提出快速可能模糊聚类分割算法,使其对各种较复杂图像的分割具有即时性。结果 通过人工合成图像和实际遥感图像分割测试结果表明,本文改进可能聚类算法是有效的,其分割轮廓清晰,分类准确且噪声较小,其误分率相比其他算法至少降低了2个百分点,同时能获得更满意的分割效果。结论 针对模糊C-均值聚类分割算法和可能性聚类分割算法对于背景和目标颜色相近的图像分类不准确的缺陷,将类内距离与类间距离相结合作为算法的测度有效的解决了图像分割归类问题,并且结合直方图提出快速可能模糊聚类分割算法使其对于大篇幅复杂图像也具有适用性。     

基于改进的直觉模糊核聚类的图像分割方法

针对噪声图像模糊性的本质，提出了基于改进的直觉模糊核聚类的图像分割方法。采用直觉模糊集描述噪声图像包含的不确定性信息，将图像的灰度信息转换到直觉模糊域进行处理；将模糊核聚类拓展为直觉模糊核聚类，在图像的直觉模糊域进行聚类；通过高斯核函数和欧氏距离分别对像素8-邻域的灰度和空间信息进行建模，综合平衡灰度和空间信息对聚类的作用，并将其作为惩罚项加入到直觉模糊核聚类的目标函数中；通过梯度下降法，推导了迭代求解算法；通过典型的合成图像和自然图像分割实例，验证了所提算法的有效性和鲁棒性。     

Improved spatial fuzzy c-means clustering for image segmentation using PSO initialization,Mahalanobis distance and post-segmentation correction

In this paper, we propose an improvement method for image segmentation using the fuzzy c-means clustering algorithm (FCM). This algorithm is widely experimented in the field of image segmentation with very successful results. In this work, we suggest further improving these results by acting at three different levels. The first is related to the fuzzy c-means algorithm itself by improving the initialization step using a metaheuristic optimization. The second level is concerned with the integration of the spatial gray-level information of the image in the clustering segmentation process and the use of Mahalanobis distance to reduce the influence of the geometrical shape of the different classes. The final level corresponds to refining the segmentation results by correcting the errors of clustering by reallocating the potentially misclassified pixels. The proposed method, named improved spatial fuzzy c-means IFCMS, was evaluated on several test images including both synthetic images and simulated brain MRI images from the McConnell Brain Imaging Center (BrainWeb) database. This method is compared to the most used FCM-based algorithms of the literature. The results demonstrate the efficiency of the ideas presented.     

Kernel generalized fuzzy c-means clustering with spatial information for image segmentation

The generalized fuzzy c-means clustering algorithm with improved fuzzy partition (GFCM) is a novel modified version of the fuzzy c-means clustering algorithm (FCM). GFCM under appropriate parameters can converge more rapidly than FCM. However, it is found that GFCM is sensitive to noise in gray images. In order to overcome GFCM?s sensitivity to noise in the image, a kernel version of GFCM with spatial information is proposed. In this method, first a term about the spatial constraints derived from the image is introduced into the objective function of GFCM, and then the kernel induced distance is adopted to substitute the Euclidean distance in the new objective function. Experimental results show that the proposed method behaves well in segmentation performance and convergence speed for gray images corrupted by noise.     

A multiobjective spatial fuzzy clustering algorithm for image segmentation

This article describes a multiobjective spatial fuzzy clustering algorithm for image segmentation. To obtain satisfactory segmentation performance for noisy images, the proposed method introduces the non-local spatial information derived from the image into fitness functions which respectively consider the global fuzzy compactness and fuzzy separation among the clusters. After producing the set of non-dominated solutions, the final clustering solution is chosen by a cluster validity index utilizing the non-local spatial information. Moreover, to automatically evolve the number of clusters in the proposed method, a real-coded variable string length technique is used to encode the cluster centers in the chromosomes. The proposed method is applied to synthetic and real images contaminated by noise and compared with k-means, fuzzy c-means, two fuzzy c-means clustering algorithms with spatial information and a multiobjective variable string length genetic fuzzy clustering algorithm. The experimental results show that the proposed method behaves well in evolving the number of clusters and obtaining satisfactory performance on noisy image segmentation.     

A clustering algorithm with optimized multiscale spatial texture information: application to SAR image segmentation

An image segmentation method based on optimized spatial texture information is proposed in this article. Spatial information, including the relative position of neighbouring pixels and texture features of the multiscale neighbourhood, is incorporated into the similarity measure of the fuzzy c-means (FCM) clustering algorithm, in which the Gaussian kernel is adopted to diminish the local incorrect segmentation. The FCM clustering is spatially adjusted and optimized by the particle swarm optimization (PSO) algorithm. The purpose of optimization is to obtain the appropriate control parameters influencing spatial information, which can improve segmentation results. Experimental results demonstrate that the proposed method achieves better segmentation performance and is capable of effectively segmenting synthetic images and synthetic aperture radar (SAR) images.     

结合模糊聚类算法的图像分割方法

在介绍聚类分析原理的基础上,比较了几种聚类分割算法,得出了模糊C-均值聚类方法在图像分割中的优势.最后,基于排列组合熵和灰度特征,结合模糊C-均值聚类算法对图像纹理进行分割.实验结果表明,该方法既能快速地分割图像,又具有较好的抗噪能力,分割效果较为理想.     

Novel segmentation algorithm in segmenting medical images

The aim of this paper is to develop an effective fuzzy c-means (FCM) technique for segmentation of Magnetic Resonance Images (MRI) which is seriously affected by intensity inhomogeneities that are created by radio-frequency coils. The weighted bias field information is employed in this work to deal the intensity inhomogeneities during the segmentation of MRI. In order to segment the general shaped MRI dataset which is corrupted by intensity inhomogeneities and other artifacts, the effective objective function of fuzzy c-means is constructed by replacing the Euclidean distance with kernel-induced distance. In this paper, the initial cluster centers are assigned using the proposed center initialization algorithm for executing the effective FCM iteratively. To assess the performance of proposed method in comparison with other existed methods, experiments are performed on synthetic image, real breast and brain MRIs. The clustering results are validated using Silhouette accuracy index. The experimental results demonstrate that our proposed method is a promising technique for effective segmentation of medical images.