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We introduce first a sort of gray-scale morphological dilations and erosions, which might have some further applications in image analysis. Then we show that the dilation and the erosion defined here form adjunctive pairs. The duality between the dilation and the erosion and some other properties, such as the commuting property with translation and homothety, of these operators are discussed as well. 相似文献
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提高多光源汇聚光斑中心定位精度的形态学滤波方法 总被引:1,自引:1,他引:0
在激光指令传输中,为形成较大的光覆盖区域并增大光源的作用距离,将多个特性相同的激光器矩阵排列,构成组合光源。针对点阵多激光管光源在开放环境下成像光斑具有多个光能中心的特点,采用形态学滤波中的开启、闭合运算,去除背景噪声斑点,平滑光斑内部的小光斑叠加和干涉造成的不规则条、孔,使得能以简化的分割和定位算法,快速获得接近实际的完整光斑边界,光斑中心定位精度的均方差不大于1.2%。该方法能快速、高精度定位这种叠加光斑的中心,为远距离激光对准和测控提供了可靠的精度和时效保证。 相似文献
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Mosayeb Naseri Mona Abdolmaleky Fariborz Parandin Negin Fatahi Ahmed Farouk Reza Nazari 《理论物理通讯》2018,69(2):215-226
In this paper, a new quantum images encoding scheme is proposed. The proposed scheme mainly consists of four different encoding algorithms. The idea behind of the scheme is a binary key generated randomly for each pixel of the original image. Afterwards, the employed encoding algorithm is selected corresponding to the qubit pair of the generated randomized binary key. The security analysis of the proposed scheme proved its enhancement through both randomization of the generated binary image key and altering the gray-scale value of the image pixels using the qubits of randomized binary key. The simulation of the proposed scheme assures that the final encoded image could not be recognized visually. Moreover, the histogram diagram of encoded image is flatter than the original one. The Shannon entropies of the final encoded images are significantly higher than the original one, which indicates that the attacker can not gain any information about the encoded images. 相似文献
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在传统变密度法SIMP(Solid Isotropic Microstructures with Penalization)中,Sigmund灵敏度过滤策略是解决拓扑优化结果数值不稳定问题的重要方法之一。但在SIMP方法中采用Sigmund灵敏度过滤策略时,有时优化结果会有较多的灰度单元。为了减少拓扑优化结果中灰度单元的数量,提出了一种基于改进灵敏度过滤策略的SIMP方法。在过滤后单元灵敏度的计算中,增加了一个与中心单元过滤前灵敏度有关的部分,该部分在过滤后灵敏度中所占的比重需要通过过滤权重来调节。通过对灵敏度过滤需要的分析,确定了过滤半径和中心单元密度值是影响过滤权重的因素。根据拓扑优化实例的优化结果给出了过滤半径影响过滤权重的情况,并基于过滤半径对过滤权重的影响情况构建了过滤权重的函数。在改进灵敏度过滤策略的基础上,结合双重SIMP算法给出了本文SIMP方法的流程。最后,以悬臂梁结构和简支梁结构为例,验证了本文方法的有效性。与Sigmund灵敏度过滤策略相比,改进的灵敏度过滤策略能有效地减少灰度单元。与双重SIMP方法相比,本文SIMP方法能有效地减少数值不稳定现象。 相似文献
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基于多灰阶靶标的在轨辐射定标方法研究 总被引:1,自引:0,他引:1
辐射定标是光学遥感信息定量化的关键技术之一。随着高分辨光学遥感器定量化应用的发展,在轨绝对辐射定标精度的要求也越来越高。提出了一种基于多灰阶靶标的在轨定标方法,采用实际测量的漫射辐照度与总辐照度比来代替辐射传输计算的气溶胶散射,同时布设高反射率靶标以提高辐射定标精度。初步试验结果表明,基于多灰阶靶标的高分辨率光学卫星传感器在轨绝对辐射定标方法,对假定的理论模型依赖较少,能够实现全动态范围的高精度定标,不确定度优于4%,而且满足复杂环境条件的应用要求。 相似文献
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360名儿童血铅和血锌的检测及相关性分析 总被引:1,自引:0,他引:1
铅和锌是微量元素中对人体特别是儿童的生长发育有很大影响的因素。随机检测了 6间幼儿园 3 60名 3~ 6岁儿童的血锌和血铅含量水平 ,血铅 >0 1 μg/mL的儿童占 2 7 2 2 %。对高铅儿童的血锌水平与血铅正常儿童的血锌水平进行相关性比较 ,在分年龄组的比较中 ,3岁组与 6岁组存在显著性差异 (P <0 0 5 ) ;在分性别的比较中 ,男童的血锌水平存在显著性差异 (P <0 0 5 )。 相似文献
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为了使由等离子体显示器(PDP)反γ校正和有限灰度级显示方法引起的灰度损失得到改善,在分析灰度损失原因及有序抖动和随机抖动特点的基础上,提出了一种抖动与孤立像素点分离相结合的灰度级增强方法。该方法首先采用有序抖动和孤立像素点分离对γ校正后的图像进行灰度增强;然后把图像数据映射到有限灰度级,计算有限灰度级与需要显示的灰度级之间的误差;最后采用随机抖动和孤立像素点分离对有限灰度级图像进行灰度增强。实验结果表明,反γ校正和有限灰度级图像的灰度均得到了显著增强,低灰度级和中高灰度级过渡平滑,没有周期性抖动噪声,孤立像素点的亮度显著降低,图像显示效果明显优于仅采用随机抖动或有序抖动的图像。 相似文献
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Possibilities and limitations of ultrasonic tumour diagnosis in internal medicine (thyroid gland, liver, pancreas, kidney, malignant lymphomas) are discussed on the basis of a five years experience with about 4,000 examinations a year. A real time and gray-scale technique is used. The accuracy of the presented ultrasonic findings is proven by comparative studies. Besides the well known advantages of ultrasonography the independence from contrast medias must be stressed in comparison to diagnostic radiology. The main limitations of ultrasonography are the impossibility of diagnosing tumours smaller than 1.5-2 cm and the absence of an ultrasonic pattern typical of malignancy. To establish a morphobiological diagnosis, ultrasonically guided fine needle biopsy has proved to be a reliable method. 相似文献
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