基于标记分水岭和FLICM模糊聚类的图像分割方法研究

传统的分水岭算法的应用非常广泛,但是存在过分割的问题。通常有两类方法解决该问题。第一类是后处理方法,它的原理是根据分水岭分割后的结果,使用某种方法让一些区域合并在一起。第二类属于前处理方法,在应用传统分水岭算法之前先标记提取,目前已经提出了基于标记的分水岭分割算法。这种方法虽然可以在一定程度上缓解传统分水岭算法的过分割问题,但是还是会有一定的过分割。文章在基于标记的分水岭算法的基础上,利用局部信息模糊C均值聚类算法(Fuzzy Local Information C-Means Clustering,FLICM)进行区域合并。实验结果表明:所提出的方法能有效地解决图像过分割问题,且更趋近于自然分割。

A Novel Unsupervised Change Detection Method with Structure Consistency and GFLICM Based on UAV Images

With the rapid development of Unmanned Aerial Vehicle(UAV)technology,change detection methods based on UAV images have been extensively studied.However,the imaging of UAV sensors is susceptible to environmental interference,which leads to great differences of same object between UAV images.Overcoming the discrepancy difference between UAV images is crucial to improving the accuracy of change detection.To address this issue,a novel unsupervised change detection method based on structural consistency and the Generalized Fuzzy Local Information C-means Clustering Model(GFLICM)was proposed in this study.Within this method,the establishment of a graph-based structural consistency measure allowed for the detection of change information by comparing structure similarity between UAV images.The local variation coefficient was introduced and a new fuzzy factor was reconstructed,after which the GFLICM algorithm was used to analyze difference images.Finally,change detection results were analyzed qualitatively and quantitatively.To measure the feasibility and robustness of the proposed method,experiments were conducted using two data sets from the cities of Yangzhou and Nanjing.The experimental results show that the proposed method can improve the overall accuracy of change detection and reduce the false alarm rate when compared with other state-of-the-art change detection methods.

基于网点核心—边缘模型的网目调印品光谱反射率预测算法

为了更加精确地预测印刷品的颜色信息,本研究基于单个网点核心—边缘模型、印刷品光散射现象、Lambert-Beer定律和模糊局部信息C均值算法,建立了一种网目调光谱反射率预测算法。并分别采用该算法、光谱Murray-Davis模型和经典核心—边缘模型预测网目调光谱反射率,与印刷品实际测量的光谱反射率作对比验证实验。结果表明:本研究算法得到的网目调光谱反射率曲线与实测光谱反射率更加吻合,色差ΔEab均小于6,达到了很好的颜色预测效果,具有较高的预测精度。

结合模糊聚类与色彩空间的遥感图像阴影检测

高分辨率遥感图像中的阴影会导致特征信息的丢失、物体的假色调和形状失真,严重影响图像的质量。针对现有阴影检测算法对遥感图像中非匀质阴影区域及亮阴影区域易漏检、检测精度低等问题,该文结合模糊聚类及HSV色彩特征提出了一种新的遥感图像阴影检测算法。首先,对图像进行预处理,剔除亮度、饱和度与阴影区相似的干扰地物;其次,利用基于局部信息改进的模糊聚类算法对图像进行结合邻域信息的聚类,克服噪声情况下的错误聚类;最后,结合图像在HSV色彩空间的H分量和RGB空间的灰度直方图进行多阈值提取阴影,得到阴影区域。实验证明,改进算法有机结合了阴影像素点的邻域信息及色彩不变特性,在亮阴影及非匀质阴影区域检测中明显提高了检测精度。

基于Canopy聚类的噪声自适应模糊C-均值算法

针对局部空间信息的模糊C-均值算法中空间影响因子容易受到噪声影响出现错误标志的问题,提出一种融合局部和非局部空间信息的模糊C-均值聚类图像分割算法(NLWFLICM)。在WFLICM算法的模糊影响因子中引入非局部空间信息,根据噪声程度自适应地设置局部和非局部信息权重,并重新标记中心点的模糊影响因子。实验结果表明,NLWFLICM算法具有比WFLICM算法更强的鲁棒性和自适应性,并在一定程度上提高了WFLICM算法对含有大量噪声图像进行分割的鲁棒性,同时保留了图像的纹理。为了提高算法的聚类性能和收敛速度,结合Canopy算法能够快速对数据进行粗聚类的优点,提出基于Canopy聚类与非局部空间信息的FCM图像分割改进算法(Canopy-NLWFLICM),可以在NLWFLICM算法聚类前对聚类中心进行预处理,从而提高收敛速度和图像分割精度。

融合自适应局部特征与改进模糊C均值的服饰分割算法

提取人体着装图像的服饰区域时,易受光照、阴影遮盖与人体姿态、肤色等问题的影响,提出一种融合自适应局部特征与改进模糊C均值(fuzzy C-means,FCM)的服饰图像分割算法。首先,通过改进区域生长法消除阴影实现前景提取;其次,采用MDSMGR-WT超像素分割获取图像局部特征,将自适应局部信息融入双加权FCM目标方程中,实现二次精细化分割;最后,经肤色检测提取目标服饰区域。实验结果表明,该方法的准确率可达78.93%,召回率90.12%,查准率89.93%。该方法能够减少内部区域噪声,提高服饰图像的分割精度。

Three-dimensional gravity inversion based on optimization processing from edge detection

Gravity inversion requires much computation,and inversion results are often non-unique.The first problem is often due to the large number of grid cells.Edge detection method,i.e.,tilt angle method of analytical signal amplitude(TAS),helps to identify the boundaries of underground geological anomalies at different depths,which can be used to optimize the grid and reduce the number of grid cells.The requirement of smooth inversion is that the boundaries of the meshing area should be continuous rather than jagged.In this paper,the optimized meshing strategy is improved,and the optimized meshing region obtained by the TAS is changed to a regular region to facilitate the smooth inversion.For the second problem,certain constraints can be used to improve the accuracy of inversion.The results of analytic signal amplitude(ASA)are used to delineate the central distribution of geological bodies.We propose a new method using the results of ASA to perform local constraints to reduce the non-uniqueness of inversion.The guided fuzzy c-means(FCM)clustering algorithm combined with priori petrophysical information is also used to reduce the non-uniqueness of gravity inversion.The Open Acc technology is carried out to speed up the computation for parallelizing the serial program on GPU.In general,the TAS is used to reduce the number of grid cells.The local weighting and priori petrophysical constraint are used in conjunction with the FCM algorithm during the inversion,which improves the accuracy of inversion.The inversion is accelerated by the Open Acc technology on GPU.The proposed method is validated using synthetic data,and the results show that the efficiency and accuracy of gravity inversion are greatly improved by using the proposed method.

基于局部空间信息KFCM的遥感图像聚类算法

针对模糊C均值(Fuzzy C-Means,FCM)算法,不能有效地对夹杂噪声的遥感图像聚类的问题,本文提出了一种基于局部空间信息核模糊C均值(Kernel Fuzzy C-Means,KFCM)的遥感图像聚类算法。首先,运用核函数将遥感图像的所有像元映射到高维特征空间,通过非线性映射优化遥感图像的有用特征;然后,根据相邻像元之间的相关性,利用一种空间函数重新定义像元的模糊隶属度,将像元的局部空间信息引入到FCM算法中,并在高维特征空间中使用这种基于局部空间信息的FCM算法对像元聚类。由于引入了像元的局部空间信息,算法可以直接应用于原始遥感图像,不需要滤波预处理。大量实验结果表明,本文提出的基于局部空间信息KFCM的遥感图像聚类算法具有较强的抗噪能力,可得到较好的同质区域,优于现有的FCM算法、模糊局部信息C均值(Fuzzy Local Information C-Means,FLICM)算法及KFCM算法。