共查询到20条相似文献,搜索用时 187 毫秒
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针对复杂颜色和纹理特征条件下,多晶硅电池片上的色差检测问题,提出了一种基于支持向量机分类策略的多晶硅电池片色差检测方法。首先对预处理后电池片图像进行颜色模型转换和通道分离,利用Otsu方法对单通道图像进行阈值分割处理,并计算各阈值图像的区域对比度,然后根据区域对比度情况选择合适的阈值图像,利用阈值图像所提供的信息提取图像特征;最后使用支持向量机分类器来判别电池片是否存在色差缺陷。实验结果表明提出的色差检测算法可以实现多晶硅电池片色差高效检测,色差缺陷检测的准确度、误检率和检测时间分别达到96.88%, 5%和109ms。 相似文献
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一种改进的二维最小交叉熵图像分割方法 总被引:1,自引:1,他引:1
针对当前二维最小交又熵阈值法存在计算复杂度高等问题,提出了一种改进的二维最小交叉熵阈值分割方法.首先,依据图像的含噪声类型选择邻域模板并建立相应的二维直方图来提高分割效果;然后,对二维最小交又熵公式进行推导和简化处理,利用定义的数组运算推导出新型递推算法,再确定图像及其邻域图像的实际灰度级别范围,并用这种新算法在所求的灰度级别范围内搜索最佳阈值向量来降低计算复杂度;最后,使用关键阈值一对滤波后的图像进行分割达到最佳的分割效果.仿真实验结果表明,与当前的二维最小交又熵阁值分割法相比,本文提出的方法不仅分割性能及抗噪性能更强,而且分割时间大大减少,小于0.05 s. 相似文献
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R. Krishna Priya C. Thangaraj C. Kesavadas S. Kannan 《International journal of imaging systems and technology》2013,23(4):281-288
This article presents an image segmentation technique based on fuzzy entropy, which is applied to magnetic resonance (MR) brain images in order to detect brain tumors. The proposed method performs image segmentation based on adaptive thresholding of the input MR images. The image is classified into two membership functions (MFs) of the fuzzy region: Z‐function and S‐function. The optimal parameters of these fuzzy MFs are obtained using modified particle swarm optimization (MPSO) algorithm. The objective function for obtaining the optimal fuzzy MF parameters is considered to be the maximum fuzzy entropy. Through a number of examples, The performance is compared with existing entropy based object segmentation approaches and the superiority of the proposed method is demonstrated. The experimental results are compared with the exhaustive search method and Otsu's segmentation technique. The result shows the proposed fuzzy entropy‐based segmentation method optimized using MPSO achieves maximum entropy with proper segmentation of infected areas and with minimum computational time. © 2013 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 23, 281–288, 2013 相似文献
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Suresh KV Rajagopalan AN 《Journal of the Optical Society of America. A, Optics, image science, and vision》2007,24(4):984-992
Superresolution is the process of combining information from multiple subpixel-shifted low-resolution images to form a high-resolution image. It works quite well under ideal conditions but deteriorates rapidly with inaccuracies in motion estimates. We model the original high-resolution image as a Markov random field (MRF) with a discontinuity adaptive regularizer. Given the low-resolution observations, an estimate of the superresolved image is obtained by using the iterated conditional modes (ICM) algorithm, which maximizes the local posterior conditional probability sequentially. The proposed method not only preserves edges but also lends robustness to errors in the estimates of motion and blur parameters. We derive theoretically the neighborhood structure for the posterior distribution in the presence of warping, blurring, and downsampling operations and use this to effectively reduce the overall computations. Results are given on synthetic as well as real data to validate our method. 相似文献
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在分析CS(Chirp Scaling)成像算法的基础上,发现弯曲因子C,和等效调频率因子K对多普勒模糊数DAN(Doppler Ambiguity Number)的变化非常敏感,不正确的DAN,将使C,因子和E因子失效,最终导致SAR图像的清晰度下降和位置发生变化.据此提出估计星载SARDAN的新算法:将DAN的变化与描述图像清晰度的评价函数(熵或均方差)联系起来,通过观察所得图像的熵或均方差随DAN值的变化,找到最小熵或最大均方差时所对应的DAN,即为正确的值.用Radarsat的实际数据验证了算法的有效性.分析表明,基于图像均方差的DAN估计优于图像熵的DAN估计,前者在成像区域场景反差较大和较小时均适用,而后者在成像区域场景反差较小时表现不稳定. 相似文献
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There are some compelling reasons for viewing the problem of image reconstruction from noisy or incomplete data as one of statistical estimation, i.e., of choosing, from the infinity of images consistent with the data, that image which, in some statistical sense, is most plausible. Among these reasons are the soundness of the philosophical underpinning of the resulting image reconstruction process, a greater realization of the image resolution which is inherent in the data, and freedom from many of the artifacts encountered in commonly used ad hoc reconstruction schemes. One successful technique employing a principle of statistical inference is the maximum entropy technique, in which the data-consistent image with maximum configurational entropy is chosen. It is a computationally intensive approach involving a conjugate gradient search over a convex function of a vector in a space of dimensionality equal to the number of image pixels. This technique has been employed with success in situations where the data samples are modeled as linearly related to a real non-negative object. We investigate application of maximum entropy image reconstruction to the problem of high-resolution radar diagnostic imaging. The problem differs from others in which maximum entropy has been applied in that the object to be imaged is complex. Although the desired image is of the magnitude of the complex object and is thus real and non-negative, there is no linear relationship beween object magnitude and data. Rather, the data are linearly related to the complex object. Several earlier proposed methods for applying the maximum entropy principle to this problem are identified and analyzed. A method that more closely approximates true Bayesian estimation is proposed. 相似文献
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顺序形态变换的图像增强算法 总被引:1,自引:1,他引:0
根据顺序形态变换的相关概念和性质,提出了一种新的图像增强算法。该算法通过对图像做局部加权均值滤波,得到图像增强的基值分量;采用多方位结构元素与图像边缘匹配,计算图像关于各个方位结构元素的加权均值并选取其中的最大值来确定边缘;将此最大值与基值分量之差作为增强分量来扩大图像灰度梯度的动态范围;针对图像中的高灰度区和灰度剧变区,应用图像局部均值和方差自适应调节增强系数。因此,算法在抑制图像中的高频噪声的同时,能有效提升图像中的边缘和目标。实验结果表明,增强前后图像标准差由41.1515,36.9133提高到62.0535,52.8331;图像熵由15.8463,16.8998减少到15.8156,16.8324。 相似文献
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声呐图像受噪声影响严重,分辨率低,传统算法对其目标分割效果较差,为此,提出了小波域多分辨率MRF模型的声呐图像分割算法。小波域多分辨率分析有利于提取声呐图像弱特征信息;每一分辨率中的观测特征采用高斯混合模型建模,尺度内同标记的观测特征用高斯模型建模,用各向同性的双点多级逻辑(Multi-Level Logistic,MLL)模型建模每一尺度的标记场;最后,用迭代条件模式(Iterated Conditional Mode,ICM)实现多分辨率马尔可夫随机场(Multi-Resolution Markov Random Field,MRA-MRF)中能量函数的最优解,获取标记场,完成声呐图像分割。从视觉效果和定量分析两方面验证。对比实验的结果表明,该文算法能有效地提取声呐图像的弱目标信息,较好地将目标区域和背景区域分割出来,具有较高的分割精度和鲁棒性。 相似文献
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目的 为了改善荧光图像背景光照不均匀和对比度低的问题,提出一种荧光图像自适应亮度校正和低对比度增强算法。方法 根据光照成像原理,利用引导滤波提取出荧光图像的光照分量,通过改进的二维Gamma函数动态校正背景光照,利用Top-hat变换分离出校正后的前景和背景,对前景进行自适应直方图均衡化,以实现荧光图像自适应增强的目的。结果 对比传统算法,文中算法处理后的图像背景光照均匀,对比度增强效果明显,其中标准差平均提高了9.4倍,平均梯度平均提高了1.2倍,信息熵平均提高了0.2倍。结论 文中算法可以改善高通量dPCR荧光图像背景光照不均匀性,提高图像对比度,突出图像中隐藏的细节,对其他荧光图像处理也具有参考价值。 相似文献
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针对行星变速箱在运行时产生的非线性非平稳振动,且故障特征信号微弱等问题,提出一种新的特征提取方法——改进多尺度符号动力学信息熵。在传统的符号动力学信息熵原理的基础上,通过改进传统方法的符号化过程,在考虑条件概率情况下计算信息熵,并引入多尺度概念,使得所提特征具有更大优势。最后求解行星变速箱故障模拟试验台采集到的三种状态下的振动信号改进多尺度符号动力学信息熵,并基于提出的特征评价指标对改进多尺度符号动力学信息熵、时频熵、排列熵、样本熵等特征的计算结果进行了对比。结果表明,该方法能够有效的提取行星变速箱运行状态特征,具有更高的敏感度。 相似文献
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目的在彩色图像采集过程中,光源偏暗或曝光不足等因素常导致图像亮度和对比度偏低。提出一种基于颜色恒常性的低照度图像增强方法。方法利用HSV颜色空间消除颜色分量之间的相关性。保持色调分量不变,避免颜色失真;一方面使用改进后的MSR(多尺度Retinex)算法对亮度分量进行增强,提高图像的亮度和对比度;另一方面对饱和度分量进行自适应非线性拉伸以提高颜色的饱和度。结果提出的方法能够有效提高图像的对比度和信息熵,获得较好的视觉效果;将文中方法同传统MSR算法和MSRCR算法进行对比,文中方法各项客观评价指标均优于其他2种算法,并且具有更快的运行速度。结论文中方法能够快速有效地提高低照度图像的亮度和对比度,并且具有较强的颜色保真和细节再现能力,实验结果证明了文中方法的有效性。 相似文献