基于人工免疫的灰度图像多阈值自动分割

为了实现灰度图像的自动分类以及自动分割,提出了一种基于人工免疫及最优分类数的灰度图像多阈值自动分割方法.定义了灰度图像最优分类数目标函数;接着运用人工免疫算法,结合最优分类数函数对灰度图像进行自动分类,并产生最优的多阈值,从而使得图像的全自动分割成为可能.该人工免疫算法中,抗原是指最优分类数目标函数,而抗体是指最优的多阈值.通过实验证明,分类清晰,效果良好.     

基于形态特征的图像分割方法

提出了一种基于形态特征的图像分割方法,主要采用形态特征对目标分类,结合目标数学形态分析犤1犦和局部区域二值化将目标准确地分割出来。该方法主要应用于目标图像背景复杂、目标灰度变化不均、传统方法分割不理想的情况。实验证明该方法具有很强的抗干扰能力,算法简单、速度快在实际应用中分割结果令人满意。     

自适应多阈值图像分割算法

本文提出了一种新的自适应多阈值图像分割算法.它首先利用势基函数对-维灰度直方图拟合,通过势函数聚类自动确定划分类数;然后在灰度共生矩阵的基础上,依据形状连通度准则,求得使形状连通度最大的一组分割阈值;最后按该组分割阈值执行多阈值图像分割.理论分析和实验结果都表明该算法较传统阈值分割算法优越,具有运算速度快、划分效果好、抗干扰性强的特点.     

分形理论在肝脏CT影像分割中的应用研究

针对肝脏CT影像的特点,提出了基于分形理论的分割算法。根据分形维数反映图像复杂程度的定义,通过计算两次突变的分维数,来确定图像的灰度值范围,并利用该灰度值范围确定阈值。并通过实验,表明利用分形维数所得到的阈值进行分割处理较传统方法有较大改进,且该方法计算的肝脏边缘分维数也为今后评价肝脏是否发生病变提供参考数据。     

基于正则割（Ncut）的多阈值图像分割方法

在图像处理与目标识别中广为应用的阈值法是图像分割的一种重要方法,因此如何确定阈值是图像分割的关键。提出了一种新的图像阈值分割方法,把图像的一维灰度直方图的灰度级L和对应灰度级L的概率P视为二维平面上的点（L,P）,采用新的相似度函数来定义这些点之间的相似度,从而构建基于灰度级的相似度矩阵,然后使用正则割（Ncut）进行分类,根据分类结果确定图像的分割阈值。算法用基于灰度级的权值矩阵代替基于像素级的权值矩阵来描述图像像素的关系,因而需要的存储空间及实现的复杂性大大减少;与现有的阈值分割方法相比,该算法能够单阈值和多阈值分割图像,因此具有更为优越的性能。     

基于IGA与GMM的图像多阈值分割方法*

为了实现图像的有效分割,提出了一种自适应多阈值图像分割方法,能够自动获得最佳分割阈值数目和阈值。该方法对灰度直方图进行合适尺度的连续小波变换,将小波变换曲线中幅值为负的波谷点构成阈值候选集;再应用免疫遗传算法从阈值候选集中选取准阈值,准阈值的个数对应为最佳分割类数;根据准阈值构建灰度直方图的高斯混合模型,由最小误差准则求得分割阈值。仿真实验表明,该方法能够实现图像的自动多阈值分割,能够得到很好的分割结果且分割效率高,在多目标图像分割中能够得到很好的应用。     

一种自动确定分割阈值的指纹图像分割方法

针对传统的基于灰度特性的指纹图像分割方法的不足,提出了一种自动确定分割阈值的改进算法。首 先,对图像进行直方图均衡化处理。然后,提出一种自动确定分割阈值的方法,利用图像的灰度均值及方差分割图像。最后,对分割后的图像进行后处理。实验表明,该方法简单实用,处理速度快,鲁棒性好,满足实时性要求较高的自动指纹识别系统的要求,是一种行之有效的分割方法。     

基于三角级数的直方图拟合多目标图像分割

针对灰度图像多层分割如何选取多目标图像分割的准确阈值这一难点问题,提出了一种利用三角级数来对直方图包络线进行拟合,首先把直方图包络线逼近问题转化为求解三角级数的问题,再通过计算拟合函数的拐点来得到用于多目标图像分割的最优阈值的方法。实验结果表明,该方法是求解多峰值直方图图像的最优分割阈值的有效手段。     

基于口腔图像的分割算法的研究

针对传统分割算法难以解决多目标分割等问题,提出了一种改进的一维Kapur熵多阈值分割算法.该算法依据Kapur熵阈值选择原理,应用图像灰度直方图信息,利用迭代合并和选择方法建立口腔图像中的阈值分割模型,解决了图像分割中阈值的自动获取问题和多阈值并行选择问题,实现了口腔图像中牙齿和病灶的分离.形状准则和一致性准则评价方法证明了该算法在抗噪声方面明显优于自适应阈值方法.获得的分割结果较好地保留了图像的灰度信息和边缘信息,为后续的图像分析和诊断工作提供了保证.     

一种实用的多灰度层次目标分割算法

本文提出了一种较为实用的,可用于多灰度层次目标提取的分割方法.首先利用双峰法粗定阈值,然后结合大津法得到较精确的阈值来分割图像.试验结果表明该方法易于实现,运算速度快,可扩展性好,对目标灰度层次较多的图像能够产生很好的分割效果.     

基于特征散度的自适应FCM图像分割算法

图像分割是模式识别、图像理解、计算机视觉等领域的重要研究内容。基于模糊C均值聚类(FCM)的图像分割是应用较为广泛的方法之一,但其存在距离测度鲁棒性差、需预先给出初始聚类数目、未考虑图像局部相关特性等问题。为克服上述缺点,通过引入特征散度进行距离测度,并结合聚类有效性指数自适应确定初始聚类数目和根据Laws纹理测度提取图像特征等措施,提出了一种新的FCM图像分割算法。实验结果表明,该新算法可以有效地提高图像的分割效果(特别是纹理图像),其分割结果优于现有FCM图像分割方案。     

A contextual-based segmentation of compact PolSAR images using Markov Random Field (MRF) model

As the first major step in each object-oriented feature extraction approach, segmentation plays an essential role as a preliminary step towards further and higher levels of image processing. The primary objective of this paper is to illustrate the potential of Polarimetric Synthetic Aperture Radar (PolSAR) features extracted from Compact Polarimetry (CP) SAR data for image segmentation using Markov Random Field (MRF). The proposed method takes advantage of both spectral and spatial information to segment the CP SAR data. In the first step of the proposed method, k-means clustering was applied to over-segment the image using the appropriate features optimally selected using Genetic Algorithm (GA). As a similarity criterion in each cluster, a probabilistic distance was used for an agglomerative hierarchical merging of small clusters into an appropriate number of larger clusters. In the agglomerative clustering approach, the estimation of the appropriate number of clusters using the data log-likelihood algorithm differs depending on the distance criterion used in the algorithm. In particular, the Wishart Chernoff distance which is independent of samples (pixels) tends to provide a higher appropriate number of clusters compared to the Wishart test statistic distance. This is because the Wishart Chernoff distance preserves detailed data information corresponding to small clusters. The probabilistic distance used in this study is Wishart Chernoff distance which evaluates the similarity of clusters by measuring the distance between their complex Wishart probability density functions. The output of this step, as the initial segmentation of the image, is applied to a Markov Random Field model to improve the final segmentation using vicinity information. The method combines Wishart clustering and enhanced initial clusters in order to access the posterior MRF energy function. The contextual image classifier adopts the Iterated Conditional Mode (ICM) approach to converge to a local minimum and represent a good trade-off between segmentation accuracy and computation burden. The results showed that the PolSAR features extracted from CP mode can provide an acceptable overall accuracy in segmentation when compared to the full polarimetry (FP) and Dual Polarimetry (DP) data. Moreover, the results indicated that the proposed algorithm is superior to the existing image segmentation techniques in terms of segmentation accuracy.     

Color image segmentation—an innovative approach

In this paper we describe a color image segmentation system that performs color clustering in a color space and then color region segmentation in the image domain. For color segmentation, we developed a fuzzy clustering algorithm that iteratively generates color clusters using a uniquely defined fuzzy membership function and an objective function for clustering optimization. The fuzzy membership function represents belief value of a color belonging to a color cluster and the mutual interference of neighboring clusters. The region segmentation algorithm merges clusters in the image domain based on color similarity and spatial adjacency. We developed three different methods for merging regions in the image domain. Unlike many existing clustering algorithms, the image segmentation system does not require the knowledge about the number of the color clusters to be generated at each stage and the resolution of the color regions can be controlled by one single parameter, the radius of a cluster. The color image segmentation system has been implemented and tested on a variety of color images including satellite images, car and face images. The experiment results are presented and the performance of each algorithm in the segmentation system is analyzed. The system has shown to be both effective and efficient.     

Unsupervised segmentation of medical image based on difference of mutual information

Image segmentation is a very important research field in the scope of image process- ing. It has extensive application and involves almost all fields such as image understand- ing, pattern recognition and image encoding, etc. Furthermore, research of imag…     

An automatic fuzzy c-means algorithm for image segmentation

Fuzzy c-means (FCM) algorithm is one of the most popular methods for image segmentation. However, the standard FCM algorithm must be estimated by expertise users to determine the cluster number. So, we propose an automatic fuzzy clustering algorithm (AFCM) for automatically grouping the pixels of an image into different homogeneous regions when the number of clusters is not known beforehand. In order to get better segmentation quality, this paper presents an algorithm based on AFCM algorithm, called automatic modified fuzzy c-means cluster segmentation algorithm (AMFCM). AMFCM algorithm incorporates spatial information into the membership function for clustering. The spatial function is the weighted summation of the membership function in the neighborhood of each pixel under consideration. Experimental results show that AMFCM algorithm not only can spontaneously estimate the appropriate number of clusters but also can get better segmentation quality.     

基于特征加权的自适应FCM彩色图像分割算法

图像分割是模式识别、图像理解、计算机视觉等领域的重要研究内容.基于模糊C均值聚类(FCM)的图像分割是应用较为广泛的方法之一,但其存在需预先给出初始聚类数目,且要考虑各个特征对分类的不同影响等问题.通过引入ReliefF技术进行特征加权,结合聚类有效性指数自适应确定初始聚类数目、根据Laws纹理测度提取图像特征等措施,提出了一种新的FCM彩色图像分割算法.实验结果表明,该算法可以有效地提高图像分割效果,分割结果优于现有FCM图像分割方案.     

Multispectral remote sensing image segmentation using rival penalized controlled competitive learning and fuzzy entropy

This paper proposes an image segmentation approach for multispectral remote sensing imagery based on rival penalized controlled competitive learning (RPCCL) and fuzzy entropy. In this approach, the clustering center component for each band of the image is first chosen based on the fuzzy entropy histogram of the corresponding band of the image. The initial clustering centers are then formed by combining the obtained clustering center components. The number of clusters and the real clustering centers are then determined by the use of the RPCCL method. The advantages of the proposed approach are the appropriate initial cluster centers and the fact that the number of clusters is determined automatically. The results of the experiments showed that without providing the number of clustering centers before the clustering operation, the proposed method can effectively perform an unsupervised segmentation of remote sensing images.     

Probabilistic winner-take-all segmentation of images withapplication to ship detection

A recent neural clustering scheme called "probabilistic winner-take-all (PWTA)" is applied to image segmentation. It is demonstrated that PWTA avoids underutilization of clusters by adapting the form of the cluster-conditional probability density function as clustering proceeds. A modification to PWTA is introduced so as to explicitly utilize the spatial continuity of image regions and thus improve the PWTA segmentation performance. The effectiveness of PWTA is then demonstrated through the segmentation of airborne synthetic aperture radar (SAR) images of ocean surfaces so as to detect ship signatures, where an approach is proposed to find a suitable value for the number of clusters required for this application. Results show that PWTA gives high segmentation quality and significantly outperforms four other segmentation techniques, namely, 1) K-means, 2) maximum likelihood (ML), 3) backpropagation network (BPN), and 4) histogram thresholding.     

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.