用于显微细胞图象的二维自适应阈值分割算法的优化

为了改善细胞图象的分割效果 ,考虑将二维自适应阈值分割算法应用于显微细胞图象的分割 .针对细胞图象的二维直方图特点和分割要求 ,在对传统二维阈值分割算法进行优化和简化的基础上 ,通过改变阈值取值范围、优化阈值搜索方法等措施 ,提出了一种快速实现细胞图象二维自适应阈值分割算法 .仿真结果表明 ,新算法与传统算法相比 ,不仅大大减少了计算复杂性 ,同时还使分割效果得到了一定程度的改善     

基于二维阈值化与FCM相混合的图象快速分割方法

提出了一种将快速二维阈值化与模糊聚类相混合的图象分割方法，以进一步减少快速二维阈值分割中的噪声与错误分割。实验结果表明，利用这种方法分割信噪比较低的图象，能够在很短的时间内得到较为令人满意的分割结果。此外，本文还讨论了这一方法中隶属度函数的选取对分割结果的影响     

微粒群算法在二维模糊熵图像分割中的应用

将微粒群算法和二维模糊熵阏值分割法结合,提出了一种基于微粒群和二维模糊熵的图像分割方法.该方法根据像素点灰度值和区域灰度均值所建立的二维灰度直方图,以二维模糊熵作为微粒群算法的适应度函数,利用微粒群算法搜索点灰度值和区域灰度均值所对应的模糊参数最优组合,进而确定相应的分割阈值.对几例真实目标图像的对比分割实验结果表明,该文方法性能优越,是一种有效的图像分割方法.     

基于改进模糊指数熵双阈值的3维人体图像分割优化算法

由于3维人体图像数据量大,导致分割耗时严重;人体组织间灰度差异相对较小,致使分割效果不佳。针对上述3维分割的两大难点问题,提出了改进的模糊指数熵函数来改善分割结果,并以加权免疫遗传算法(WIGA)对阈值进行优化搜索,从而提出了一种基于改进模糊指数熵双阈值的3维图像分割优化算法。真实人体胸部数据的分割结果表明,与传统熵函数及模糊隶属度函数相比,改进的最大模糊指数熵函数得到的阈值分割效果更好,且提出的WIGA算法的耗时仅为传统穷尽搜索法的14%。在与简单遗传算法(SGA)和免疫遗传算法(IGA)耗时基本相同的情况下,100次阈值计算结果表明,本文算法更加精确、稳定。     

基于傅立叶变换的二维条码识别

研究了基于傅立叶变换的二维条码识别技术 .首先探讨了二维条码的定位分割技术 ,即在条码中分割出单行码字符号的图象 ,分析条码信号经过点扩展函数卷积后的降质模型 ,并讨论条码信号的一阶导数和中点的性质 ,通过分析条码信号 ,提出了一种计算点扩展函数标准方差的算法 ;然后利用傅立叶变换对条码信号进行反模糊滤波 ;最后对复原的条码信号做差分处理 ,并采用边界强度直方图策略自适应地选取阈值滤去噪声导致的无效边界 .在边界强度直方图中 ,采用基于矩阈值选取的方法寻找最佳阈值 .实验结果表明 ,该识别算法具有优秀的性能 ,显著地提高了条码的识别率 ,满足了实际使用的要求     

基于改进模糊指数熵双阈值的3维人体图像分割优化算法

由于3维人体图像数据量大,导致分割耗时严重;人体组织间灰度差异相对较小,致使分割效果不佳。针对上述3维分割的两大难点问题,提出了改进的模糊指数熵函数来改善分割结果,并以加权免疫遗传算法（WIGA）对阈值进行优化搜索,从而提出了一种基于改进模糊指数熵双阈值的3维图像分割优化算法。真实人体胸部数据的分割结果表明,与传统熵函数及模糊隶属度函数相比,改进的最大模糊指数熵函数得到的阈值分割效果更好,且提出的WIGA算法的耗时仅为传统穷尽搜索法的14%。在与简单遗传算法（SGA）和免疫遗传算法（IGA）耗时基本相同的情况下,100次阈值计算结果表明,本文算法更加精确、稳定。     

基于边界特征的一维最大熵图像分割算法的研究与实现

本文提出了一种新的图象分割算法，该算法首先检测边缘，在边界图象的基础上进行图象二值化，保留了边界特征，而且能自适应地选择阈值，克服了一维最大熵阈值方法进行图象分割时丢失边界特征的缺点。大量实验表明该算法取得了很好的效果，而且可以处理低质量或边缘模糊的图象，具有一定的推广实用价值。     

基于边界特征的一维最大熵图像分割算法的研究与实现

本文提出了一种新的图象分割算法，该算法首先检测边缘，在边界图象的基础上进行图象二值化，保留了边界特征，而且能自适应地选择阈值，克服了一维最大熵阈值方法进行图象分割时丢失边界特征的缺点。大量实验表明该算法取得了很好的效果，而且可以处理低质量或边缘模糊的图象，具有一定的推广实用价值。     

基于凸多项式模糊熵的图象阈值方法

采用一种凸多项式代替模糊熵中的香农函数,提出了基于凸多项式模糊 图象阈值方法,以颗粒图象为应用实例,对其进行了验证。实验结果表明,该算法对颗粒图象的分割十分有效。     

改进的二维Otsu算法在SF6压力表盘图像分割中的研究

为了提高SF6压力表盘图像分割准确度,对比了传统二维Otsu和Otsu双阈值分割算法,给出了一种改进二维Otsu算法.针对二维Otsu算法选取最佳阈值时存在的缺陷,将整体阈值再区分并结合离差平方和作为适应度函数选取最佳阈值,提高了目标图像的阈值分割效果.实验结果表明:所提算法不仅满足对SF6压力表盘图像进行目标区域分割,同时具有更高的稳定性、快速性和分割精度.     

Segmentation of remotely sensed images with fuzzy thresholding,and quantitative evaluation

Effectiveness of various fuzzy thresholding techniques (based on entropy of fuzzy sets, fuzzy geometrical properties, and fuzzy correlation) is demonstrated on remotely sensed (IRS and SPOT) images. A new quantitative index for image segmentation using the concept of homogeneity within regions is defined. Results are compared with those of probabilistic thresholding, and fuzzy c-means and hard c-means clustering algorithms, both in terms of index value (quantitatively) and structural details (qualitatively). Fuzzy set theoretic algorithms are seen to be superior to their respective non-fuzzy counterparts. Among all the techniques, fuzzy correlation, followed by fuzzy entropy, performed better for extracting the structures. Fuzzy geometry based thresholding algorithms produced a single stable threshold for a wide range of membership variation.     

Robust fuzzy clustering-based image segmentation

The fuzzy clustering algorithm fuzzy c-means (FCM) is often used for image segmentation. When noisy image segmentation is required, FCM should be modified such that it can be less sensitive to noise in an image. In this correspondence, a robust fuzzy clustering-based segmentation method for noisy images is developed. The contribution of the study here is twofold: (1) we derive a robust modified FCM in the sense of a novel objective function. The proposed modified FCM here is proved to be equivalent to the modified FCM given by Hoppner and Klawonn [F. Hoppner, F. Klawonn, Improved fuzzy partitions for fuzzy regression models, Int. J. Approx. Reason. 32 (2) (2003) 85–102]. (2) We explore the very applicability of the proposed modified FCM for noisy image segmentation. Our experimental results indicate that the proposed modified FCM here is very suitable for noisy image segmentation.     

基于有偏场的光栅图像模糊聚类分割算法*

针对有偏场环境下带有光栅的散焦图像分割问题,提出了一种新的基于有偏场估计的模糊聚类分割算法。通过建立依赖于有偏场的模糊聚类目标函数,导出了基于灰度以及邻域灰度均值的聚类中心、模糊聚类函数以及有偏场估计的迭代算法;并在该算法生成的初始分割基础上,利用膨胀算子对分类结果进行细化。该方法较好地处理了传统模糊聚类对有偏场下光栅图像分割精度下降的问题。实验结果表明,基于有偏场的模糊聚类算法能有效分割光栅图像,其分割精度优于传统模糊聚类和阈值法。     

Skin cancer extraction with optimum fuzzy thresholding technique

This paper discusses a new approach to segment different types of skin cancers using fuzzy logic approach. The traditional skin cancer segmentation involves the analysis of image features to delineate the cancerous region from the normal skin. Using low level features such as colour and intensity, segmentation can be done by obtaining a threshold level to separate the two regions. Methods like Otsu optimisation provide a quick and simple process to optimise such threshold level; however this process is prone to the lighting and skin tone variations. Fuzzy clustering algorithm has also been widely used in image processing due to its ability to model the fuzziness of human visual perception. Classical fuzzy C means (FCM) clustering algorithm has been applied to image segmentation with good results; however, the classical FCM is based on type-1 fuzzy sets and is unable to handle uncertainties in the images. In this paper, we proposed an optimum threshold segmentation algorithm based on type-2 fuzzy sets algorithms to delineate the cancerous area from the skin images. By using the 3D colour constancy algorithm, the effect of colour changes and shadows due to skin tone variation in the image can be significantly reduced in the preprocessing stage. We applied the optimum thresholding technique to the preprocessed image over the RGB channels, and combined individual results to achieve the overall skin cancer segmentation. Compared to the Otsu algorithm, the proposed method is less affected by the shadows and skin tone variations. The results also showed more tolerance at the boundary of the cancerous area. Compared with the type-1 FCM algorithm, the proposed method significantly reduced the segmentation error at the normal skin regions.     

Fuzzy c-means clustering with non local spatial information for noisy image segmentation

As an effective image segmentation method, the standard fuzzy c-means (FCM) clustering algorithm is very sensitive to noise in images. Several modified FCM algorithms, using local spatial information, can overcome this problem to some degree. However, when the noise level in the image is high, these algorithms still cannot obtain satisfactory segmentation performance. In this paper, we introduce a non local spatial constraint term into the objective function of FCM and propose a fuzzy cmeans clustering algorithm with non local spatial information (FCM_NLS). FCM_NLS can deal more effectively with the image noise and preserve geometrical edges in the image. Performance evaluation experiments on synthetic and real images, especially magnetic resonance (MR) images, show that FCM_NLS is more robust than both the standard FCM and the modified FCM algorithms using local spatial information for noisy image segmentation.     

基于谱聚类的多闭值图像分割方法

阈值法是图像分割的一种重要方法,在图像处理与目标识别中广为应用。因此,如何确定阈值是图像分割的关键。提出了一种新的图像阈值分割方法,即通过采用新的相似度函数的谱聚类算法(Dcut)确定图像阈值。采用基于灰度级的权值矩阵代替常用的基于图像像素级的权值矩阵描述图像像素的关系,因而算法需要的存储空间及实现的复杂性与其它基于图的图像分割方法相比大大减少。实验表明,该方法分割图像的时间少,且能够单阈值和多阈值分割图像,与现有的阈值分割方法相比,其具有更为优越的分割性能。     

A multi-scale 3D Otsu thresholding algorithm for medical image segmentation

Thresholding technique is one of the most imperative practices to accomplish image segmentation. In this paper, a novel thresholding algorithm based on 3D Otsu and multi-scale image representation is proposed for medical image segmentation. Considering the high time complexity of 3D Otsu algorithm, an acceleration variant is invented using dimension decomposition rule. In order to reduce the effects of noises and weak edges, multi-scale image representation is brought into the segmentation algorithm. The whole segmentation algorithm is designed as an iteration procedure. In each iteration, the image is segmented by the efficient 3D Otsu, and then it is filtered by a fast local Laplacian filtering to get a smoothed image which will be input into the next iteration. Finally, the segmentation results are pooled to get a final segmentation using majority voting rules. The attractive features of the algorithm are that its segmentation results are stable, it is robust to noises and it holds for both bi-level and multi-level thresholding cases. Experiments on medical MR brain images are conducted to demonstrate the effectiveness of the proposed method. The experimental results indicate that the proposed algorithm is superior to the other multilevel thresholding algorithms consistently.     

A two-stage fuzzy multi-objective framework for segmentation of 3D MRI brain image data

Segmentation of Magnetic Resonance Imaging (MRI) brain image data has a significant impact on the computer guided medical image diagnosis and analysis. However, due to limitation of image acquisition devices and other related factors, MRI images are severely affected by the noise and inhomogeneity artefacts which lead to blurry edges in the intersection of the intra-organ soft tissue regions, making the segmentation process more difficult and challenging. This paper presents a novel two-stage fuzzy multi-objective framework (2sFMoF) for segmenting 3D MRI brain image data. In the first stage, a 3D spatial fuzzy c-means (3DSpFCM) algorithm is introduced by incorporating the 3D spatial neighbourhood information of the volume data to define a new local membership function along with the global membership function for each voxel. In particular, the membership functions actually define the underlying relationship between the voxels of a close cubic neighbourhood and image data in 3D image space. The cluster prototypes thus obtained are fed into a 3D modified fuzzy c-means (3DMFCM) algorithm, which further incorporates local voxel information to generate the final prototypes. The proposed framework addresses the shortcomings of the traditional FCM algorithm, which is highly sensitive to noise and may stuck into a local minima. The method is validated on a synthetic image volume and several simulated and in-vivo 3D MRI brain image volumes and found to be effective even in noisy data. The empirical results show the supremacy of the proposed method over the other FCM based algorithms and other related methods devised in the recent past.     

灰度图像交叉熵阈值法的三维推广

针对现有的灰度图像交叉熵阈值化方法无法有效分割含有混合噪声图像的问题,在图像三维直方图的基础上提出三维交叉熵阈值化算法,同时给出三维交叉熵阈值法的快速递推公式.实验结果表明,三维方法结合了图像中像素的灰度及其局部空间的均值和中值信息,对于含有混合噪声的图像,具有比现有交叉熵阈值化算法更好的分割效果.     

自适应最小误差阈值分割算法

对二维最小误差法进行三维推广, 并结合三维直方图重建和降维思想提出了一种鲁 棒的最小误差阈值分割算法. 但该方法为全局算法, 仅适用于分割均匀光照图像. 为 提高其自适应性, 本文采用Water flow模型对非均匀光照图像进行背景估计, 以此获 得原始图像与背景图像的差值图像, 达到降低非均匀光照对图像分割造成干扰的目的. 为进 一步提高分割性能, 本文对差值图像采用γ 矫正进行增强, 然后采用鲁棒最小误差 法进行全局分割, 从而完成目标提取. 最后本文对均匀光照下以及非均匀光照下图像进行了 实验, 并与一维最小误差法、二维最小误差法、三维直方图重建和降维的Otsu阈值分割 算法、灰度波动变换自适应阈值方法以及一种改进的FCM方法在错误分割率和运行时间上进 行了对比. 实验结果表明, 相对于以上方法, 本算法的分割性能均有明显提升.