Color image segmentation using feedforward neural networks with FCM

This paper proposes a hybrid technique for color image segmentation. First an input image is converted to the image of CIE L*a*b* color space. The color features “a” and “b” of CIE L*a*b* are then fed into fuzzy C-means (FCM) clustering which is an unsupervised method. The labels obtained from the clustering method FCM are used as a target of the supervised feed forward neural network. The network is trained by the Levenberg-Marquardt back-propagation algorithm, and evaluates its performance using mean square error and regression analysis. The main issues of clustering methods are determining the number of clusters and cluster validity measures. This paper presents a method namely co-occurrence matrix based algorithm for finding the number of clusters and silhouette index values that are used for cluster validation. The proposed method is tested on various color images obtained from the Berkeley database. The segmentation results from the proposed method are validated and the classification accuracy is evaluated by the parameters sensitivity, specificity, and accuracy.     

基于遗传模糊C-均值聚类算法的地图分割

图像分割和对象提取是从图像处理到图像分析的关键步骤。经典的模糊C-均值聚类算法(FCMA)是将图像分割成C类的常用方法,但依赖于初始聚类中心的选择。该算法通常得到的是局部最优解而非全局最优解。遗传算法是一类全局优化搜索算法。通过将遗传算法(GA)与FCMA相结合,对彩色地图直接按红绿蓝(RGB)三色空间进行聚类,用遗传算法搜索全局最优解,有效地避免了模糊C-均值聚类算法收敛到局部最优的问题,并在此基础上实现了对彩色地图的分割,得到了比较满意的效果。     

Oppositional symbiotic organisms search optimization for multilevel thresholding of color image

Selection of optimal threshold is the most crucial issue in threshold-based segmentation. In case of color image, this task is become challenging, because conventional color image segmentation has computational complexity and also it suffers from lack of accuracy. Various techniques such as threshold based, region growing, edge detection, graph cut, pixel classification, neural network, active contour, gray level co-occurrence matrix are proposed so far for image segmentation in the literature. Out of them, threshold-based segmentation is popular for its simplicity. To address the problem of color image segmentation, we propose an enhanced version of metaheuristic optimization algorithm called Opposition based Symbiotic Organisms Search (OSOS) to solve multilevel image thresholding technique for color image segmentation by introducing opposition based learning concepts to accelerate the convergence rate and enhance the performance of standard symbiotic organisms search (SOS). The performance of the proposed OSOS based algorithm is investigated thoroughly and compared with some existing techniques like Cuckoo Search (CS), BAT algorithm (BAT), artificial bee colony (ABC) and particle swarm optimization (PSO). The comparison is made by applying the algorithm to a set of color images taken from a well-known benchmark dataset (Berkeley Segmentation Dataset (BSDS)) and some of the color images collected for the COCO dataset. It is observed from the results that the performance of the OSOS based algorithm is promising with respect to standards SOS and others in terms of the values of objective functions as well as the values of some well-defined quality metrics such as peak signal-to-noise ratio (PSNR), structure similarity index (SSIM) and feature similarity index (FSIM). The results of the proposed algorithm may encourage the scientists and engineers to apply it into pattern recognition problems.     

基于云模型的彩色图像分割方法

以云模型理论为基础分析彩色图像分割概念,研究已有的彩色图像分割方法,并与云模型相结合,提出基于云模型的彩色图像分割方法。该方法在HSV颜色空间对彩色图像进行非均匀量化,并寻找量化后图像的基本直方图,最后通过云模型的“3En规则”对图像进行前景/背景分割。通过与K均值算法、IS-RSC算法进行比较,实验结果表明了该方法对彩色图像分割的有效性。     

显著特征融合的主颜色聚类分割算法*

针对颜色密度聚类分割模型容易产生误分割的问题,提出基于视觉显著性调节的主颜色聚类分割算法.首先,根据空间颜色信息和Mean-shift算法平滑结果分别计算图像的全局显著特征和区域显著特征,并融合2类显著特征作为特征空间聚类的约束项.然后,采用核密度估计方法计算图像主颜色作为初始类,并将显著特征作为调节因子进行聚类分割.最后,进行区域合并.在标准的分割图像库上进行实验并与多种算法对比,结果表明,文中算法具有更高的区域轮廓准确度,并且有效利用图像显著特征,降低密度聚类形成的区域不一致性,提高像素聚类的精度和分割的鲁棒性.     

一种融合聚类与区域生长的彩色图像分割方法

论文提出了一种将聚类和区域生长有机融合的彩色图像分割方法。为了捕获图像的纹理特征,首先将图像划分成16×16子块,然后在块中按照视觉一致性准则进行颜色聚类,对于聚类后的子块,提取其颜色与纹理特征,然后采用符合人类视觉特征的生长规则,进行基于子块的区域生长。该方法充分利用了聚类算法和区域生长算法的各自优点,并符合人类视觉特征的分割策略。利用提出的算法对多幅自然图像进行了分割实验,实验结果证明了算法的有效性。     

A local-coloring method for night-vision colorization utilizing image analysis and fusion

A natural color mapping method has been previously proposed that matches the statistical properties (mean and standard deviation) of night-vision (NV) imagery to those of a daylight color image (manually selected as the “target” color distribution). Thus the rendered NV image appears to resemble the natural target image in terms of color appearance. However, in this prior method (termed “global-coloring”) the colored NV image may appear unnatural if the target image’s “global” color statistics are different from that of the night-vision scene (e.g., it would appear to have too much green if much more vegetation was contained in the target image). Consequently, a new “local-coloring” method is presented that functions to render the NV image segment-by-segment by taking advantage of image segmentation, pattern recognition, histogram matching and image fusion. Specifically, a false-color image (source image) is formed by assigning multi-band NV images to three RGB (red, green and blue) channels. A nonlinear diffusion filter is then applied to the false-colored image to reduce the number of colors. The final grayscale segments are obtained by using clustering and merging techniques. With a supervised nearest-neighbor paradigm, a segment can be automatically associated with a known “color scheme”. The statistic-matching procedure is merged with the histogram-matching procedure to enhance the color mapping effect. Instead of extracting the color set from a single target image, the mean, standard deviation and histogram distribution of the color planes from a set of natural scene images are used as the target color properties for each color scheme. The target color schemes are grouped by their scene contents and colors such as plants, mountain, roads, sky, water, etc. In our experiments, five pairs of night-vision images were initially analyzed, and the images that were colored (segment-by-segment) by the proposed “local-coloring” method are shown to possess much more natural and realistic coloration when compared with those produced by the previous “global-coloring” method.     

Strategic bidding using fuzzy adaptive gravitational search algorithm in a pool based electricity market

A novel stochastic optimization approach to solve optimal bidding strategy problem in a pool based electricity market using fuzzy adaptive gravitational search algorithm (FAGSA) is presented. Generating companies (suppliers) participate in the bidding process in order to maximize their profits in an electricity market. Each supplier will bid strategically for choosing the bidding coefficients to counter the competitors bidding strategy. The gravitational search algorithm (GSA) is tedious to solve the optimal bidding strategy problem because, the optimum selection of gravitational constant (G). To overcome this problem, FAGSA is applied for the first time to tune the gravitational constant using fuzzy “IF/THEN” rules. The fuzzy rule-based systems are natural candidates to design gravitational constant, because they provide a way to develop decision mechanism based on specific nature of search regions, transitions between their boundaries and completely dependent on the problem. The proposed method is tested on IEEE 30-bus system and 75-bus Indian practical system and compared with GSA, particle swarm optimization (PSO) and genetic algorithm (GA). The results show that, fuzzification of the gravitational constant, improve search behavior, solution quality and reduced computational time compared against standard constant parameter algorithms.     

基于鱼群算法优化normalized cut的彩色图像分割方法

为了克服传统的谱聚类算法求解normalized cut彩色图像分割时,分割效果差、算法复杂度高的缺点,提出了一种基于鱼群算法优化normalized cut的彩色图像分割方法.先对图像进行模糊C-均值聚类预处理,然后用鱼群优化算法替代谱聚类算法求解Ncut的最小值,最后通过最优个体鱼得到分割结果.实验表明,该方法耗时少,且分割效果好.     

基于图割精细化和可微分聚类的无监督显著性目标检测

针对传统显著性检测算法分割精度低以及基于深度学习的显著性检测算法对像素级人工注释数据依赖性过强等不足,提出一种基于图割精细化和可微分聚类的无监督显著性目标检测算法。该算法采用由“粗”到“精”的思想,仅利用单张图像的特征便可以实现精确的显著性目标检测。首先利用Frequency-tuned算法根据图像自身的颜色和亮度得到显著粗图,然后根据图像的统计特性进行二值化并结合中心优先假设得到显著目标的候选区域,进而利用基于单图像进行图割的GrabCut算法对显著目标进行精细化分割,最后为克服背景与目标极为相似时检测不精确的困难,引入具有良好边界分割效果的无监督可微分聚类算法对单张显著图做进一步的优化。所提出的算法在ECSSD和SOD数据集上进行测试并与现有的7种算法进行对比,结果表明得到的优化显著图更接近于真值图,在ECSSD和SOD数据集上分别实现了14.3%和23.4%的平均绝对误差（MAE）。     

Genetic algorithm and self organizing map based fuzzy hybrid intelligent method for color image segmentation

The grouping of pixels based on some similarity criteria is called image segmentation. In this paper the problem of color image segmentation is considered as a clustering problem and a fixed length genetic algorithm (GA) is used to handle it. The effectiveness of GA depends on the objective function (fitness function) and the initialization of the population. A new objective function is proposed to evaluate the quality of the segmentation and the fitness of a chromosome. In fixed length genetic algorithm the chromosomes have same length, which is normally set by the user. Here, a self organizing map (SOM) is used to determine the number of segments in order to set the length of a chromosome automatically. An opposition based strategy is adopted for the initialization of the population in order to diversify the search process. In some cases the proposed method makes the small regions of an image as separate segments, which leads to noisy segmentation. A simple ad hoc mechanism is devised to refine the noisy segmentation. The qualitative and quantitative results show that the proposed method performs better than the state-of-the-art methods.     

基于马氏距离的FCM图像分割算法

基于模糊C均值聚类的图像分割是应用较为广泛的方法之一,但大多数模糊C均值聚类方法都是基于欧式距离,且存在运算时间过长等问题。提出了一种基于Mahalanobis距离的模糊C均值聚类图像分割算法。实验分析表明,提出的算法在保证分割质量的前提下,能较快提高分割速度。实验结果表明了该方法的有效性。     

基于K均值聚类与区域合并的彩色图像分割算法

提出一种基于K均值聚类与区域合并的彩色图像分割算法。首先,对图像运用mean shift算法进行滤波,在对图像进行平滑的同时保持图像的边缘;然后,运用K均值算法对图像在颜色空间进行聚类,得到初始分割的结果;最后,给出了一种区域合并策略,对初始分割获得的区域进行合并,得到最终的分割结果。仿真结果表明,算法的分割结果和人的主观视觉感知具有良好的一致性。     

一种基于主色外观图的彩色图像分割算法

在对三维传统的颜色直方图(CCH)作出了一系列改进的基础上,提出了一种基于主色外观图(DCG)的新的彩色图像分割方法.首先根据改进后的颜色直方图确立彩色图像的近似主色成分,然后再利用CIE-1976色差公式分别计算出其每个像素与主色之间的距离,并据此建立相应图像的颜色距离直方图(CDH),它精确地反映了图像像素与参考色之间的色彩相似度.为了证实CDH在彩色图像分割中的效用性,又通过进一步地扩展得到了CDH集,或可称为主色外观图.实验结果表明,就精确性、鲁棒性和计算的复杂度而言,基于DCG的分割方法能够得到比传统阈值法和聚类法更好的分割效果.     

基于颜色量化和密度峰聚类的彩色图像分割

彩色图像分割是簇绒地毯数字化制造的关键技术,图像的分割质量直接影响到后续的图像处理。为解决地毯的彩色图像分割问题,针对人眼在RGB颜色空间中感知不均匀的特性,提出了一种基于颜色量化和密度峰聚类的彩色图像分割算法。基于Lab颜色空间进行颜色量化,在HVC颜色空间中用NBS距离来衡量人眼对颜色差异的感知程度,采用改进的密度峰聚类算法自动确定聚类中心,从而分割地毯图案。实验结果表明,该算法能在不影响人眼感知的前提下得到颜色种类少且边缘清晰的地毯分割图像。     

自适应烟花算法下多维模糊C均值彩色图像分割

针对图像分割在自然场景中,分割精度不高和细节保持不够敏感,提出一种自适应烟花算法下的多维模糊C均值彩色图像分割算法。结合动态时间弯曲思想,以邻域像素相似特点构造弯曲曲线,得到多维相似距离和新的目标函数。在自适应烟花寻优算法下,找到最优聚类中心,最终达到对图像分割效果。实验表明,该算法与同类算法相比,对彩色图像有良好的分割效果,对图像的细节保持也不错。     

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。     

Plant disease leaf image segmentation based on superpixel clustering and EM algorithm

Plant disease leaf image segmentation plays an important role in the plant disease detection through leaf symptoms. A novel segmentation method of plant disease leaf image is proposed based on a hybrid clustering. The whole color leaf image is firstly divided into a number of compact and nearly uniform superpixels by superpixel clustering, which can provide useful clustering cues to guide image segmentation to accelerate the convergence speed of the expectation maximization (EM) algorithm, and then, the lesion pixels are quickly and accurately segmented from each superpixel by EM algorithm. The experimental results and the comparison results with similar approaches demonstrate that the proposed method is effective and has high practical value for plant disease detection.

     

空间模糊C均值聚类的神经切片图像分割方法

周围神经切片显微图像具有背景复杂、区域不连续和光照不均匀等特点,应用经典的图像分割算法难以取得有效的分割结果。通过结合初始隶属度概率函数和空间距离来设计空间函数而得到的SFCM聚类算法,并提出SFCM彩色图像分割方法。把图像从RGB颜色空间转换到HIS颜色空间。采用聚类有效性分析指标在直方图快速FCM算法中为HSI各分量确定分类数目和获取SFCM初始化参数。对HIS各分量分别进行SFCM聚类,合并各分量并转换回RGB彩色空间以显示结果。实验结果表明,与标准FCM聚类分割算法相比,新方法能更有效地分割区域不连续的神经切片显微图像。