基于区域信息的Snake模型医学图像分割

本文针对Snake模型应用于图像边缘检测时对于噪音过于敏感的不足和易于从弱边界溢出．提出了一种新的约束力。在新的约束力的作用下，Snake模型可以很好地减小噪音的干扰，防止曲线溢出弱边界，并使初始曲线具有更大的选择空间，使模型的分割性能更好。实验证明该模型可以分割出较好的目标边界。     

基于Snake模型的复杂区域图像分割

在复杂区域图像分割中,针对传统Snake模型不能收敛到深凹陷区域等缺点,从内部能量函数和算法实现两方面入手对传统Snake模型进行改进,增加了一项由力作功产生的能量项,并采用Greey算法分两阶段实现.结果表明,改进的Snake模型能迅速地收敛到深凹陷区域和更复杂区域,且减弱了分割结果对初值的依赖性和噪声点对边界的影响.     

基于超像素分割的RGB与高光谱图像融合

本文提出了一种基于超像素分割的RGB与高光谱图像融合方法。首先,利用在线字典学习法由低空间分辨率的高光谱图像数据学习得到光谱字典。然后,通过光谱字典的线性变换,得到与高光谱图像同一场景的RGB图像字典。其次,对RGB图像进行超像素分割,并根据分割结果在每一个超像素块中进行稀疏编码,得到稀疏矩阵中的系数包含了RGB图像的空间信息。最后,将稀疏编码矩阵与高光谱图像谱字典相结合重建得到高空间分辨率高光谱图像。实验结果表明,该方法不管是在主观视觉上的图像恢复质量,还是在峰值信噪比等客观指标上均具有优势。     

一种基于模糊C均值的图像超像素分割方法

在分析现有图像分割算法基础上,提出一种基于超像素的模糊C均值分割算法.首先利用像素间灰度和距离定义像素间相似度,从而循环迭代出图像的超像素;然后进一步提取每个超像素的小波能量特征并利用模糊C均值算法对该特征进行聚类.大量实验表明,提出的图像分割算法对噪声有一定稳健性,分割准确率高,并能有效抑制孤立点的影响.     

一种快速的超像素分割方法

围绕图像分割算法介绍了一种快速的超像素分割算法,传统的分割算法在算法效率,计算成本,复杂度等方面均存在问题。围绕着以上问题,进而提出了一种改进型的算法:超像素分割算法SLIC,并通过实验测试数据性能参数比对,证明了该种算法的优越性,且获得了更好的品质和更高的计算效率。     

基于随机森林和超像素分割优化的车载红外图像彩色化算法

为了将红外图像中所包含的信息更加友好、直观地呈现给用户,改善用户对于红外图像的理解效果,针对车载红外图像的特点,提出了一种基于随机森林分类器和超像素分割算法相结合的车载红外图像彩色化算法。首先对原图的各个像素点进行特征提取,然后训练随机森林分类器,使它能够对待测试图像的各个像素点进行正确的分类。再使用超像素分割与直方图统计相结合的方法对分类结果图像进行优化。最后将优化后的分类结果图像转换到 HSV 色彩空间进行对应的色彩传递。通过实验证明该方法能够在很好的对红外图像进行彩色化处理的同时,保证色彩传递的正确性和实时性。     

基于分水岭的超像素分割方法

超像素算法作为一种预处理工具已在计算机视觉中得到了广泛应用,尤其在实时视觉系统中,超像素算法的高效性尤为重要。文中是基于分水岭算法而提出的高效超像素分割算法,即空间约束的分水岭算法(SCoW),SCoW算法是通过一组均匀标集来进行分水岭分割。该算法通过引入边缘预处理来确保均匀性和紧凑性之间的平衡,从而对齐超像素的图像边缘,且无任何复杂计算。文中提出的算法比传统算法所产生的超像素图像质量好且运行效率高。     

基于超像素多特征融合的快速图像分割算法

为了提高高分辨率图像分割效率,解决复杂图案中待分割目标边缘附近前景与背景区分度小而造成的分割目标不完整问题,本文通过引入超像素HOG特征,提出了一种基于超像素多特征融合（superpixel multi-feature fusion,SMFF）的快速图像分割算法.首先采用目前最有效的超像素算法对待分割图像进行超像素预分割,然后提取基于超像素的HOG特征、Lab颜色特征和空间位置特征,设计基于超像素的多特征度量算法,最终采用图割理论实现了基于超像素多特征融合的快速图像分割.实验结果验证了本文算法的有效性,其算法性能接近于目前最经典图像分割算法,且本文算法的时间性能要明显优于其它对比算法.     

基于梯度的极化SAR图像超像素分割

超像素分割在图像分割领域以其优异的性能表现被广泛应用,准确性和高效性是评价分割性能的重要指标.简单线性迭代聚类（simple linear iterative clustering,SLIC）方法在光学图像上表现出了优异的性能,在极化合成孔径雷达（synthetic aperture radar,SAR）图像中也被广泛应用,然而SLIC方法中的初始化步骤不能准确地定位类中心,需要多次的迭代纠正误差.改进的分水岭方法（spatial constrained watershed,SCoW）是一种基于梯度阈值区分的简单且高效的分割方法,但是不能直接用于极化SAR图像.本文受SCoW的启发,提出一种对SLIC进行预处理的分割方法,通过横虚警（constant false alarm rate,CFAR）边缘检测器计算得到极化SAR图像的梯度信息,并将梯度信息用于初始化分割.基于两幅实测极化SAR图像,将本文提出方法与其他三种方法对比.实验表明本文方法可以减少整个算法的迭代次数,得到更加符合图像信息、贴合图像边界的分割结果.     

一种新的图像超像素分割方法

针对现有超像素分割方法无法自动确定合适的超像素数目,以及难以有效贴合图像目标边界等问题,该文提出一种新的利用局部信息进行多层级简单线性迭代聚类的图像超像素分割方法。首先,运用基于局部信息的简单线性迭代聚类(LI-SLIC)对原始图像进行超像素初分割,然后,根据超像素的色彩标准差对其进行自适应多层级迭代分割,直至每个超像素块的色彩标准差小于预设阈值,最后,利用相邻超像素间的色彩差异对过分割的超像素进行合并。为验证方法的有效性,该文采用Berkeley, Pascal VOC和3Dircadb公共数据库作为实验数据集,并与其他多种超像素分割方法进行了比较。实验结果表明,该文提出的超像素分割方法能更精确贴合图像目标边界,有效抑制图像过分割和欠分割。

     

Automatic pectoral muscle segmentation on mediolateral oblique view mammograms

Mammograms are X-ray images of the breast which are used to detect breast cancer. When mammograms are analyzed by computer, the pectoral muscle should preferably be excluded from processing intended for the breast tissue. For this and other reasons, it is important to identify and segment out the pectoral muscle. In this paper, a new, adaptive algorithm is proposed to automatically extract the pectoral muscle on digitized mammograms; it uses knowledge about the position and shape of the pectoral muscle on mediolateral oblique views. The pectoral edge is first estimated by a straight line which is validated for correctness of location and orientation. This estimate is then refined using iterative "cliff detection" to delineate the pectoral margin more accurately. Finally, an enclosed region, representing the pectoral muscle, is generated as a segmentation mask. The algorithm was found to be robust to the large variations in appearance of pectoral edges, to dense overlapping glandular tissue, and to artifacts like sticky tape. The algorithm has been applied to the entire Mammographic Image Analysis Society (MIAS) database of 322 images. The segmentation results were evaluated by two expert mammographic radiologists, who rated 83.9% of the curve segmentations to be adequate or better.     

Robust automatic breast and pectoral muscle segmentation from scanned mammograms

Breast skin–air interface and pectoral muscle segmentation are usually first steps in all CAD applications on scanned as well as digital mammograms. Breast skin–air interface segmentation is much more difficult task when performed on scanned mammograms than on digital mammograms. In case of pectoral muscle segmentation, segmentation difficulty of analog and digital mammograms is usually similar. In this paper we present adaptive contrast enhancement method for breast skin–air interface detection which combines usage of adaptive histogram equalization method on small region of interest which contains actual edge and edge detection operators. Pectoral muscle detection method uses combination of contrast enhancement using adaptive histogram equalization and polynomial curvature estimation on selected region of interest. This method makes segmentation of very low contrast pectoral muscle areas possible because of estimation used to segment areas which have lower contrast difference than detection threshold.     

基于Snake活动轮廓模型的视频跟踪分割方法

基于Snake活动轮廓模型,采用时空融合的方式,根据短时间内相邻帧的运动趋势差异相似的前提,首先将视频序列分成若干个小段,每段有k帧视频,选取段内的前两帧为关键帧,通过运动检测的方式自动得到这两帧中运动对象的大致区域;然后进行帧内Snake演变,搜索精确轮廓;最后以关键帧间运动对象形心的运动矢量预测勾勒后续帧的初始轮廓,进行帧内Snake精确轮廓定位,从而实现所有帧的视频对象分割。相比于传统方法,本文方法克服了手动绘制初始轮廓的缺点,在空域对Snake贪婪方法进行了改进而且精确度高,速度快。实验表明,本文方法成功地实现了前后帧图像之间运动对象的对应匹配关系,并通过改进后的Snake贪婪方法得到了精确的分割结果。     

萤火虫群优化算法多阈值的脑CT图像分割

在基于多阈值的脑,CT图像分割算法中,最佳阈值选取是脑CT图像中的关键,针对传统多阈值法的阈值选择难题为了提高脑。CT图像的分割准确率,提出一种萤火虫群算法优化多阈值的脑CT图像分割方法首先建立了基于多阈值法的脑图像分割数学模型,然后通过萤火虫群算法数学模型进行求解,搜索到脑CT图像分割的最佳阈值,CT最后采用最佳阈值完成脑CT图像的分割。仿真结果表明,萤火虫群算法提高了脑CT图像的精度,获得了更加理想的脑CT图像结果。     

Automated seeded lesion segmentation on digital mammograms

Segmenting lesions is a vital step in many computerized mass-detection schemes for digital (or digitized) mammograms. The authors have developed two novel lesion segmentation techniques-one based on a single feature called the radial gradient index (RGI) and one based on simple probabilistic models to segment mass lesions, or other similar nodular structures, from surrounding background. In both methods a series of image partitions is created using gray-level information as well as prior knowledge of the shape of typical mass lesions. With the former method the partition that maximizes the RGI is selected. In the latter method, probability distributions for gray-levels inside and outside the partitions are estimated, and subsequently used to determine the probability that the image occurred for each given partition. The partition that maximizes this probability is selected as the final lesion partition (contour). The authors tested these methods against a conventional region growing algorithm using a database of biopsy-proven, malignant lesions and found that the new lesion segmentation algorithms more closely match radiologists' outlines of these lesions. At an overlap threshold of 0.30, gray level region growing correctly delineates 62% of the lesions in the authors' database while the RGI and probabilistic segmentation algorithms correctly segment 92% and 96% of the lesions, respectively     

The image segmentation based on optimized spatial feature of superpixel

This paper proposes a method of image segmentation based on superpixels. The method is applied to achieve the segmentation of synthetic aperture radar (SAR) image. Firstly, the superpixels are extracted based on multi-scale features. Then, the fuzzy c-means (FCM) clustering based on superpixels is implemented, in which the influence of neighboring and similar superpixels is incorporated into FCM and the influential degree is optimized to improve segmentation performance. Experimental results show that the proposed method can achieve an impressive accuracy of SAR segmentation. For application extension, when we extract corresponding feature from several types of specific images, the proposed method is able to achieve better segmentation performance.     

综合利用通用霍夫变换与Snake算法对序列图像的分割

提出了一种综合算法对图像序列进行分割:首先根据上一帧图像物体形状信息用霍夫变换确定在当前帧中同一物体的大致轮廓、位置,再以此轮廓作为初始值,用Snake算法检测出物体的局部形变,对于序列的第一帧用手工勾出目标物体大致轮廓.由于通用霍夫变换抗噪声能力强,而Snake能准确地找出局部形变物体的边缘,综合两种算法的特点能精确地分割出复杂背景下特定的物体.     

基于改进Chan-Vese模型的图像分割

目前基于水平集的图像分割方法很难给出基于全局极值的算法终止条件,而大多采用事先设定迭代次数的方法。本文提出了一种改进的Chan-Vese模型,通过添加水平集函数约束项,使得新模型抑制了水平集函数的取值范围,最终收敛至全局极值,并以此作为算法终止条件,无需事先设定迭代次数。实验结果表明,新模型在其终止条件下,分割结果正确,与传统Chan-Vese模型相比,新模型的收敛速度快3~6倍,且通用性更强。     

Foreground segmentation based on selective foreground model

Foreground segmentation often fails when the background and foreground exhibit similar colour distributions. In this reported work, the general foreground model as a set of latest sequential segmentations is challenged, and it is asserted that the latest samples are not always best suited for foreground modelling. Proposed is a selective foreground model composed of the best suited samples chosen from all historical segmentations based on colour histogram similarity, with the time order of segmentations being ignored. Experiments demonstrate that the selective foreground model is efficient in solving the colour similarity problem.     

基于Chan-Vese模型的多相位图像分割

利用Chan-Vese模型,对多相位图像实现了串行分层分割。首先得到目标和背景2个子区域,然后判断各子区域内部是否仍包含有感兴趣的目标,如果有,则对该子区域再次采用Chan-Vese模型进行分割,如此迭代直到分割出图像中所有的目标。较之采用Mumford-Shah模型,本文方法计算简单,而且对多相位图像中的目标定位准确,每一层分割都可以得到有意义的区域。实验表明,本文方法可以有效、准确地实现对多相位图像的分割。