用于彩图分割的自适应谱聚类算法

针对自调节谱聚类算法的缺陷,提出一种新的自适应谱聚类算法。它用全局平均N近邻距离作为比例参数σ,利用本征矢差异来估计最佳聚类分组数k,达到了比前者更好的效果,且更容易实现。在彩色图像分割实际应用中的实验结果表明,该算法适应性强、计算代价小、精度较高,性能好于或至少不差于以往的类似算法。     

基于HSI空间模糊聚类的彩色图像分割新方法

模糊C均值(FCM)被广泛应用于彩色图像分割中,但传统的模糊C均值由于没有考虑空间信息,因此对噪声特别敏感。针对此问题,提出了一种在HIS颜色空间结合像素邻域空间信息的模糊聚类新方法。实验结果表明,此方法对高噪声图像有较好的处理结果。     

一种快速的模糊C均值聚类彩色图像分割方法

FCM用于彩色图像分割存在聚类数目需要事先确定、计算速度慢的问题,为此,提出一种快速的模糊C均值聚类方法（FFCM）。首先,对原始彩色图像进行基于梯度图的分水岭变换,从而把原始彩色图像数据分成一些具有色彩一致性的子集;然后,利用这些子集的大小和中心点进行模糊聚类。由于FFCM聚类样本数量显著减小,因此可以大幅提高模糊C均值聚类算法的计算速度,进而可以采用聚类有效性指标确定聚类数目。实验表明,这种方法不需要事先确定聚类数目,在聚类有效性能不变的前提下,可以使模糊聚类的速度得到明显提高,实现了彩色图像的快速分割。     

混合聚类彩色图像分割方法研究

提出了一种基于K-均值算法和EM算法混合聚类的彩色图像分割方法。首先将待分割的RGB彩色图像转化成YUV空间模型,然后将该图像分割成n小块,对每个块的颜色分量用改进的K-均值聚类算法进行聚类分析,最后用EM聚类算法对每个块进行聚类,分割源图像。对K-均值算法和EM算法的初始聚类中心引进了改进算法,加快了算法的收敛速度。并与相似的分割方法进行了比较实验,给出了详细的实验结果与分析。实验表明该方法分割速度快,效果好,具有较高的实用价值。     

基于半监督的超像素谱聚类彩色图像分割算法

近年来谱聚类算法被广泛应用于图像分割领域,而相似性矩阵的构造是谱聚类算法的关键步骤。 针对传统谱聚类算法计算复杂度高难以应用到大规模图像分割处理的问题,提出了基于半监督的超像素谱聚类彩色图像分割算法。该算法利用超像素将彩色图像进行预分割,利用用户提供的少量标记信息构造预分割区域的基于半监督的模糊相似性测度,利用该相似性测度构造预分隔区域的相似性矩阵并通过规范切图谱划分准则对预分割区域进行划分得到最终的图像分割结果。由于少量标记信息和模糊理论的引入,提高了传统谱聚类的分割性能,对比实验也表明该算法在分割效果和计算复杂度上都有较大的改善。     

Color image segmentation using tensor voting based color clustering

A novel color image segmentation method using tensor voting based color clustering is proposed. By using tensor voting, the number of dominant colors in a color image can be estimated efficiently. Furthermore, the centroids and structures of the color clusters in the color feature space can be extracted. In this method, the color feature vectors are first encoded by second order, symmetric, non-negative definite tensors. These tensors then communicate with each other by a voting process. The resulting tensors are used to determine the number of clusters, locations of the centroids, and structures of the clusters used for performing color clustering. Our method is based on tensor voting, a non-iterative method, and requires only the voting range as its input parameter. The experimental results show that the proposed method can estimate the dominant colors and generate good segmented images in which those regions having the same color are not split up into small parts and the objects are separated well. Therefore, the proposed method is suitable for many applications, such as dominant colors estimation and multi-color text image segmentation.     

K-harmonic means clustering algorithm using feature weighting for color image segmentation

This paper mainly proposes K-harmonic means (KHM) clustering algorithms using feature weighting for color image segmentation. In view of the contribution of features to clustering, feature weights which can be updated automatically during the clustering procedure are introduced to calculate the distance between each pair of data points, hence the improved versions of KHM and fuzzy KHM are proposed. Furthermore, the Lab color space, local homogeneity and texture are utilized to establish the feature vector to be more applicable for color image segmentation. The feature group weighting strategy is introduced to identify the importance of different types of features. Experimental results demonstrate the proposed feature group weighted KHM-type algorithms can achieve better segmentation performances, and they can effectively distinguish the importance of different features to clustering.

     

应用于彩色图像分割的半监督多目标进化聚类算法*

为了有效的使用用户给定的先验信息,并从多个角度考虑图像分割问题,本文提出了应用于彩色图像分割的半监督多目标进化模糊聚类算法。首先,将半监督方法引入到多目标进化聚类算法中,通过使用少量的监督信息指导聚类过程;其次,将最大熵正则化引入到带有监督信息的目标函数中,使目标函数具有清晰的物理意义;最后,利用监督信息构造基于相似性度量的有效指标从非支配解集中选择一个最优解。实验结果表明,该算法与传统的多目标进化聚类算法及半监督模糊聚类算法相比具有更好的灵活性和准确性。     

自适应快速FCM彩色图像分割研究

模糊C均值聚类算法（FCM）广泛用于彩色图像分割,但该算法存在需要预先指定聚类数目、计算量大、耗时长且易陷入局部最优等缺点。提出一种自适应快速模糊C均值彩色图像分割方法,该方法首先运用蚁群算法,自动获取初始聚类中心和聚类数目,然后使用基于梯度的分水岭算法对原始彩色图像进行预分割,得到一系列由色彩特征空间具有一致性的点构成的子集,最后对这些子集的中心进行模糊聚类。实验结果表明：由于子集数量远小于原始图像像素数目,使聚类样本数量显著减少,大大提高了聚类速度,同时在聚类中以特征距离代替欧式距离,增强了算法的鲁棒性。     

An adaptive unsupervised approach toward pixel clustering and color image segmentation

This paper proposes an adaptive unsupervised scheme that could find diverse applications in pattern recognition as well as in computer vision, particularly in color image segmentation. The algorithm, named Ant Colony-Fuzzy C-means Hybrid Algorithm (AFHA), adaptively clusters image pixels viewed as three dimensional data pieces in the RGB color space. The Ant System (AS) algorithm is applied for intelligent initialization of cluster centroids, which endows clustering with adaptivity. Considering algorithmic efficiency, an ant subsampling step is performed to reduce computational complexity while keeping the clustering performance close to original one. Experimental results have demonstrated AFHA clustering's advantage of smaller distortion and more balanced cluster centroid distribution over FCM with random and uniform initialization. Quantitative comparisons with the X-means algorithm also show that AFHA makes a better pre-segmentation scheme over X-means. We further extend its application to natural image segmentation, taking into account the spatial information and conducting merging steps in the image space. Extensive tests were taken to examine the performance of the proposed scheme. Results indicate that compared with classical segmentation algorithms such as mean shift and normalized cut, our method could generate reasonably good or better image partitioning, which illustrates the method's practical value.     

基于微粒群优化的模糊C-均值聚类彩色图像分割

模糊C-均值聚类算法广泛用于图像分割,但存在聚类性能受类中心初始化影响,且计算量大等问题。为此,提出了一种基于微粒群的模糊C-均值聚类图像分割算法,该方法利用微粒群较强的搜索能力搜索聚类中心。由于搜索聚类中心是按密度进行,计算量小,故可以大幅提高模糊C-均值算法的计算速度。实验表明,这种方法可以使模糊聚类的速度得到明显提高,实现图像的快速分割。     

Consensus-based clustering for document image segmentation

Segmentation of a document image plays an important role in automatic document processing. In this paper, we propose a consensus-based clustering approach for document image segmentation. In this method, the foreground regions of a document image are grouped into a set of primitive blocks, and a set of features is extracted from them. Similarities among the blocks are computed on each feature using a hypothesis test-based similarity measure. Based on the consensus of these similarities, clustering is performed on the primitive blocks. This clustering approach is used iteratively with a classifier to label each primitive block. Experimental results show the effectiveness of the proposed method. It is further shown in the experimental results that the dependency of classification performance on the training data is significantly reduced.     

一种织物彩色图像的分割算法

提出了一种针对织物彩色图像的分割算法。该算法在颜色聚类的基础上,把每种颜色用 不同的序号来表示,生成一个与原图同大小的序号矩阵,然后根据矩阵中序号的分布进行初始分割并 产生种子区域,再把初始分割未能确定的像素指派到种子区域中,最后根据颜色信息合并过分割的区 域,并对区域边缘进行平滑,得到最终的分割结果。实验表明,该算法能较有效地实现各类彩色织物 图像的分割。     

Multiresolution color image segmentation

Image segmentation is the process by which an original image is partitioned into some homogeneous regions. In this paper, a novel multiresolution color image segmentation (MCIS) algorithm which uses Markov random fields (MRF's) is proposed. The proposed approach is a relaxation process that converges to the MAP (maximum a posteriori) estimate of the segmentation. The quadtree structure is used to implement the multiresolution framework, and the simulated annealing technique is employed to control the splitting and merging of nodes so as to minimize an energy function and therefore, maximize the MAP estimate. The multiresolution scheme enables the use of different dissimilarity measures at different resolution levels. Consequently, the proposed algorithm is noise resistant. Since the global clustering information of the image is required in the proposed approach, the scale space filter (SSF) is employed as the first step. The multiresolution approach is used to refine the segmentation. Experimental results of both the synthesized and real images are very encouraging. In order to evaluate experimental results of both synthesized images and real images quantitatively, a new evaluation criterion is proposed and developed     

Enabling scalable spectral clustering for image segmentation

Spectral clustering has become an increasingly adopted tool and an active area of research in the machine learning community over the last decade. A common challenge with image segmentation methods based on spectral clustering is scalability, since the computation can become intractable for large images. Down-sizing the image, however, will cause a loss of finer details and can lead to less accurate segmentation results. A combination of blockwise processing and stochastic ensemble consensus are used to address this challenge. Experimental results indicate that this approach can preserve details with higher accuracy than comparable spectral clustering image segmentation methods and without significant computational demands.     

快速模糊C均值聚类的图像分割方法

模糊C均值(FCM)聚类算法广泛应用于图像的自动分割,但标准的FCM算法存在计算量大,运算速度慢等问题。对FCM算法进行改进,提出了一种快速FCM图像分割算法(FFCM),该算法将图像从像素空间映射到其灰度直方图特征空间,并在此基础上,充分利用像素的邻域特性,对隶属度函数做一定改进,实验结果表明该算法能快速有效地分割图像,并具有较好的抗噪能力。     

Adaptive spatial information-theoretic clustering for image segmentation

The incorporation of spatial context into clustering algorithms for image segmentation has recently received a significant amount of attention. Many modified clustering algorithms have been proposed and proven to be effective for image segmentation. In this paper, we propose a different framework for incorporating spatial information with the aim of achieving robust and accurate segmentation in case of mixed noise without using experimentally set parameters based on the original robust information clustering (RIC) algorithm, called adaptive spatial information-theoretic clustering (ASIC) algorithm. The proposed objective function has a new dissimilarity measure, and the weighting factor for neighborhood effect is fully adaptive to the image content. It enhances the smoothness towards piecewise-homogeneous segmentation and reduces the edge blurring effect. Furthermore, a unique characteristic of the new information segmentation algorithm is that it has the capabilities to eliminate outliers at different stages of the ASIC algorithm. These result in improved segmentation result by identifying and relabeling the outliers in a relatively stronger noisy environment. Comprehensive experiments and a new information-theoretic proof are carried out to illustrate that our new algorithm can consistently improve the segmentation result while effectively handles the edge blurring effect. The experimental results with both synthetic and real images demonstrate that the proposed method is effective and robust to mixed noise and the algorithm outperforms other popular spatial clustering variants.