Biomedical Image Processing Using FCM Algorithm Based on the Wavelet Transform

An effective processing method for biomedical images and the Fuzzy C-mean ( FCM ) algorithm based on the wavelet transform are investigated. By using hierarchical wavelet decomposition, an original image could be decomposed into one lower image and several detail images. The segmentation started at the lowest resolution with the FCM clustering algorithm and the texture feature extracted from various sub-bands. With the improvement of the FCM algorithm, FCM alternation freqneney was decreased and the accuracy of segmentation was advanced .     

A method of automatic image segmentation for gas bubbles in water

This paper presents an algorithm of automatic bubble image segmentation using the improved ant colony optimization methodology. The ant colony optimization method is a metaheuristic algorithm, and has been applied in many fields. To reveal the versatility and appropriateness of automatic bubble image segmentation, the fuzzy clustering analysis method is employed in ant colony optimization algorithm. Compared with the well-known image feature extraction operators such as SUSAN and Canny, the proposed method can comparatively suitable to extract the gas bubbles image edge features. The experimental results show that the proposed method is effective and reliable, and can achieve satisfactory image edge extraction effect.     

Classification of hyperspectral remote sensing images based on simulated annealing genetic algorithm and multiple instance learning简

A hybrid feature selection and classification strategy was proposed based on the simulated annealing genetic algonthrn and multiple instance learning （MIL）. The band selection method was proposed from subspace decomposition, which combines the simulated annealing algorithm with the genetic algorithm in choosing different cross-over and mutation probabilities, as well as mutation individuals. Then MIL was combined with image segmentation, clustering and support vector machine algorithms to classify hyperspectral image. The experimental results show that this proposed method can get high classification accuracy of 93.13% at small training samples and the weaknesses of the conventional methods are overcome.     

Local sparse representation for astronomical image denoising

Motivated by local coordinate coding(LCC) theory in nonlinear manifold learning, a new image representation model called local sparse representation(LSR) for astronomical image denoising was proposed. Borrowing ideas from surrogate function and applying the iterative shrinkage-thresholding algorithm(ISTA), an iterative shrinkage operator for LSR was derived. Meanwhile, a fast approximated LSR method by first performing a K-nearest-neighbor search and then solving a l1optimization problem was presented under the guarantee of denoising performance. In addition, the LSR model and adaptive dictionary learning were incorporated into a unified optimization framework, which explicitly established the inner connection of them. Such processing allows us to simultaneously update sparse coding vectors and the dictionary by alternating optimization method. The experimental results show that the proposed method is superior to the traditional denoising method and reaches state-of-the-art performance on astronomical image.     

3D reconstruction method based on contour features

To guarantee the accuracy and real-time of the 3D reconstruction method for outdoor scene, an algorithm based on region segmentation and matching was proposed. Firstly, on the basis of morphological gradient information, obtained by comparing color weight gradient images and proposing a multi-threshold segmentation, scene contour features were extracted by a watershed algorithm and a fuzzy c-means clustering algorithm. Secondly, to reduce the search area, increase the correct matching ratio and accelerate the matching speed, the region constraint was established according to a region''s local position, area and gray characteristics, the edge pixel constraint was established according to the epipolar constraint and the continuity constraint. Finally, by using the stereo matching edge pixel pairs, their 3D coordinates were estimated according to the binocular stereo vision imaging model. Experimental results show that the proposed method can yield a high stereo matching ratio and reconstruct a 3D scene quickly and efficiently.     

Improved SLIC Segmentation Algorithm for Artificial Structure Images

Simple linear iterative cluster(SLIC) is widely used because controllable superpixel number, accurate edge covering, symmetrical production and fast speed of calculation. The main problem of the SLIC algorithm is its under-segmentation when applied to segment artificial structure images with unobvious boundaries and narrow regions. Therefore, an improved clustering segmentation algorithm to correct the segmentation results of SLIC is presented in this paper. The allocation of pixels is not only related to its own characteristic, but also to those of its surrounding pixels.Hence, it is appropriate to improve the standard SLIC through the pixels by focusing on boundaries. An improved SLIC method adheres better to the boundaries in the image is proposed, by using the first and second order difference operators as magnified factors. Experimental results demonstrate that the proposed method achieves an excellent boundary adherence for artificial structure images. The application of the proposed method is extended to images with an unobvious boundary in the Berkeley Segmentation Dataset BSDS500. In comparison with SLIC, the boundary adherence is increased obviously.     

Layout problem of multi-component systems arising for improving maintainability

To improve the mainlainability design efficiency and quality, a layout optimization method for maintainability of multi-component systems was proposed. The impact of the component layout design on system maintainability was analyzed, and the layout problem for maintainability was presented. It was formulated as an optimization problem, where maintainability, layout space and distance requirement were formulated as objective functions. A multi-objective particle swarm optimization algorithm, in which the constrained-domination relationship and the update strategy of the global best were simply modified, was then used to obtain Pareto optimal solutions for the maintainability layout design problem. Finally, application in oxygen generation system of a spacecraft was studied in detail to illustrate the effectiveness and usefulness of the proposed method. The results show that the concurrent maintainability design can be carried out during the layout design process by solving the layout optimization problem for maintainability.     

Multi-modality liver image registration based on multilevel B-splines free-form deformation and L-BFGS optimal algorithm简

A new coarse-to-fine strategy was proposed for nonrigid registration of computed tomography （CT） and magnetic resonance （MR） images of a liver. This hierarchical framework consisted of an affine transformation and a B-splines free-form deformation （FFD）. The affine transformation performed a rough registration targeting the mismatch between the CT and MR images The B-splines FFD transformation performed a finer registration by correcting local motion deformation. In the registration algorithm, the normalized mutual information （NMI） was used as similarity measure, and the limited memory Broyden-Fletcher- Goldfarb-Shannon （L-BFGS） optimization method was applied for optimization process. The algorithm was applied to the fully automated registration of liver CT and MR images in three subjects. The results demonstrate that the proposed method not only significantly improves the registration accuracy but also reduces the running time, which is effective and efficient for nonrigid registration.     

Dual optimization image repair algorithm based on linear structure and optimal texture

The performances of repaired image depend on the local information in the repaired area and the consistency between the repair directions with structural content. Image repair algorithm with texture information performs well in repairing seriously damaged images, but it has bad performances when the images have the abundant structure information. The dual optimization image repair algorithm based on the linear structure and the optimal texture is proposed. The algorithm uses the double-constraint sparse model to reconstruct the missed information in large area in order to improve the clarity of repaired images. After adopting the preference of Criminisi priority, the image repair algorithm of self-similarity characteristics is proposed to improve the fault and fuzzy distortion phenomena in the repaired image. The results show that the proposed algorithm has more clarity in the image texture and structure and better effectiveness, and the peak signal-to-noise ratio of the repaired images by proposed algorithm is superior to that by other algorithms.     

Employment of predictive search algorithm in digital image correlation

A predictive search algorithm to estimate the size and direction of displacement vectors was presented.The algorithm decreased the time of calculating the displacement of each pixel.In addition,the updating reference image scheme was used to update the reference image and to decrease the computation time when the displacement was larger than a certain number.In this way,the search range and computational complexity were cut down,and less EMS memory was occupied.The capability of proposed search algorithm was then verified by the results of both computer simulation and experiments.The results showed that the algorithm could improve the efficiency of correlation method and satisfy the accuracy requirement for practical displacement measuring.     

基于空间信息及隶属度约束的FCM图像分割算法

针对传统的模糊C均值(FCM)算法在图像分割方面存在的缺点,提出一种基于空间信息及隶属度约束的FCM图像分割算法.该算法在传统FCM算法的目标函数中引入图像空间信息及对隶属度的约束,使得到的聚类中心更加合理,并且增强了算法对噪音的鲁棒性.实验结果表明,本算法可以有效地提高图像分割的质量.     

改进的基于遗传模糊C均值聚类的图像分割算法

模糊C均值（Fuzzy C-Means,FCM）聚类算法已广泛应用于图像分割领域,其本质是一种局部搜索算法,采用迭代爬山算法寻找最优解,对初始聚类中心敏感,很容易陷入局部极优值,且没有考虑图像的空间邻域信息,对噪声敏感。本文提出了改进的基于遗传模糊聚类的图像分割算法,利用遗传算法的全局寻优能力来克服FCM算法容易陷入局部极优值问题;并在FCM算法的目标函数中添加空间邻域信息来约束隶属度函数从而提高对噪声的鲁棒性,使分割更加符合期望。实验结果表明本文算法的有效性,图像分割时具有较强的抗噪能力和较好的分割效果。     

模糊C-均值聚类图像分割算法的一种改进

针对传统模糊C-均值聚类算法对含噪图像分割时未充分考虑空间信息的问题,提出一种改进的模糊C-均值聚类算法,将图像的局部和非局部两种空间信息引入到模糊C-均值聚类算法的目标函数中,以使两种空间信息在含噪图像分割中发挥互补作用。将改进算法应用于不同含噪图像的分割实验,结果表明图像像素的均方误差均比改进前有所降低。     

蚁群算法在二维Otsu图像分割中的应用

提出了一种基于蚁群算法和二维Otsu的图像分割方法,利用蚁群算法快速寻优的特点,求出二维Otsu图像分割的阈值分割点,对图像进行分割。根据源图像和邻域平滑后图像的灰度,以及灰度频数进行聚类。通过灰度直方图的峰值点设置精确的初始聚类中心,解决了蚁群算法运算次数多、计算量大的问题;针对具体应用,对聚类半径、信息激素和启发引导函数进行了修正。实验表明该算法速度快、划分特性好、抗噪声能力强,可以准确地分割出目标。     

基于均值距离的图像分割方法

针对医学图像分割中存在的分割类数不易确定的问题,利用常用均值间的不等式关系构造出了一种新的分割类数判据--均值距离函数,并将均值距离函数与模拟退火算法相结合,提出了一种基于均值距离的分割算法。该算法以均值距离函数作为目标函数,采用模拟退火算法进行优化,在整个搜索空间中寻找最优分割阈值,弥补了模糊C均值算法(fuzzy C-means,FCM)分类类数难以确定、搜索过程容易陷入局部极值的缺陷。实验结果表明,算法对含有病灶的医学图像能够进行自动分割,并且分割速度明显高于基于互信息的分割方法。     

NSCT变换与空间约束模糊核聚类红外图像分割算法

红外图像成像模糊、易受噪声污染,分辨率低,采用标准的FCM分割算法会出现失效和误分割。通过对以往各种方法的研究,根据红外图像的特点及FCM算法的不足,提出采用在NSCT变换域进行去噪预处理与改进的FCM算法相结合的分割算法。首先对红外图像进行NSCT变换,在变换域,采用自适应阈值法去除各细节子带中的噪声,其次在FCM算法中引入核映射将数据映射到非线性空间中进行聚类划分,最后采用邻域信息修正当前像素的隶属度值,得到更准确的聚类结果。实验结果证明该算法较FCM、KFCM、SFCM聚类分割算法有更好的分割精度。     

基于混沌粒子群和模糊聚类的图像分割算法研究

针对模糊C-均值聚类算法受初始聚类中心和隶属度矩阵的影响,易陷入局部最优解,以至于得不到最佳聚类结果等问题,提出了一种新的基于混沌粒子群的模糊C-均值聚类的图像分割算法。该算法采用逻辑自映射函数初始化均匀分布的粒子群,当算法陷入早熟收敛时进行混沌优化,以改善因粒子停滞而收敛到局部最优解的能力。实验结果表明,该算法具有更快的分割速度和更高的分割精度。     

基于差分粒子群和模糊聚类的彩色图像分割算法

彩色图像数据信息量较大,传统的模糊C均值聚类算法（FCM）在分割时更加容易受到初始聚类中心影响陷入局部极值．文中研究了一种融合差分演化、粒子群和模糊均值聚类的彩色图像分割算法（DEPSO—FCM）．利用差分演化算法的快速收敛特性、粒子群算法的全局搜索能力,解决模糊均值聚类图像分割时易受到初始聚类中心影响和陷入局部最优的问题。同时针对不同的色彩空间对于图像分割效果的影响,尝试在不同的空间上使用DEPSO-FCM进行图像分割．实验表明,该方法能解决FCM算法陷入局部最优的问题,在不同的色彩空间上都获得了理想的分割效果．     

一种基于粗集与FCM结合的图像分割方法

传统的FCM 算法在做图像分割时,只是利用图像的每一个像素点的灰度值进行聚类,当图像受到噪声污染时,分割的准确性将大大降低,为此,提出了一种粗集与FCM算法相结合的图像分割方法,实验结果表明,该方法具有良好的分割性能.