基于光照-反射成像模型和形态学操作的多谱段图像增强算法

为解决多谱段降质图像增强问题,提出了一种基于光照-反射成像模型和形态学操作的多谱段图像增强算法.首先对图像饱和度使用自适应非线性拉伸函数进行拉伸,使增强后的图像色彩更加饱和、自然;接下来利用引导滤波算法提取出图像的光照分量,提出了一种基于细节特征的加权融合策略,利用光照分布特性构造了一种自适应Gamma校正函数对光照分量进行处理,并将其与利用对比度受限的自适应直方图均衡化方法处理后的光照分量以及原始光照分量进行融合;然后在反射分量校正时,构造了一种形态学操作函数来校正反射信息;最后合并光照分量和反射分量,并与处理后的饱和度分量和色调分量一起得到增强图像.采用主客观评价指标对可见光低照度图像、水下图像、高动态范围图像、沙尘暴图像、雾天图像和热红外图像6种降质多谱段图像实验结果进行分析比较,结果表明本文算法能够有效地抑制图像噪声、增强图像细节信息、改善图像视觉效果,可应用于多种图像增强领域.     

基于YCbCr颜色空间的Retinex低照度图像增强方法研究

针对Retinex理论的低照度图像增强算法中光照图像估计问题,提出一种基于YCbCr颜色空间的低照度图像增强方法.该方法将原始低照度图像从RGB(Red Green Blue)颜色空间转换到YCbCr颜色空间,提取该空间中Y分量构建为原始光照图像分量L1(x,y),并对L1(x,y)进行Gamma校正得到增强的光照图像分量L2(x,y),经Retinex模型得到增强图像R(x,y),采用多尺度细节增强方法对图像R(x,y)进行细节增强,得到最终增强图像Re(x,y).实验结果表明,所提方法不仅能有效提升亮度,避免亮度和色彩失真,增强了图像的细节信息并获得了更好的视觉效果,而且运行速度快.     

基于改进梯度和自适应窗口的立体匹配算法

立体匹配技术是计算机视觉领域的研究热点,由于问题本身的病态性,一直没有得到很好地解决。针对现有局部立体匹配算法精度不高以及易受光照失真影响的问题,提出了一种基于改进梯度匹配代价和自适应窗口的匹配算法。在传统梯度向量仅包含幅度信息的基础上,引入相位信息,并对原始匹配代价进行变换,进一步消除异常值;利用图像结构和色彩信息构建自适应窗口进行代价聚合;提出了一种局部视差直方图的视差精化方法,获得了高精度的视差图。实验结果表明,所提算法在Middlebury测试平台上平均误匹配误差为6.1%,且对光照失真条件具有较高的稳健性。     

构成白光LED的单色光对中国淡彩绘画色彩的影响

为得到构成白光LED光谱的主要单色光对中国传统淡彩绘画色彩的影响规律,确定不同波长单色光对绘画色彩的量化损伤程度,进而根据研究结果得到最低损伤白光LED的光谱功率分布,以构成白光LED光谱的4种主要单色光作为实验光源,分组照射中国传统淡彩绘画模型试件。在每个照射周期后,对试件的色彩参数进行检测,根据检测数据绘制主波长、兴奋纯度、亮度3个参数随总曝光量积累的衰变曲线,基于曲线分析得到各种淡彩绘画颜料在光照下的色彩衰变规律,并根据实验数据计算得到4种单色光对绘画色彩主波长的影响关系为482 nm∶510 nm∶583 nm∶650 nm=8 147∶9 067∶9 772∶9 121;对兴奋纯度的影响关系为482 nm∶510 nm∶583 nm∶650 nm=89 446∶85 250∶76 895∶69 229;对亮度的影响关系为482 nm∶510 nm∶583 nm∶650 nm=137∶238∶190∶177。     

基于光影图像获取光照信息的研究与实现

为了解决现有方法在获取光照是否为直射光且强度是否达到或超过一定值这两个光照信息时存在的问题,提出了一种基于计算机Matlab程序的图像处理,从光照形成的光影图像中自动获取上述光照信息的方法。分析了光影图像的特征与光照信息的关系,在实验室条件下拍摄了网格光影图像;用Matlab语言设计了处理程序并应用于获取该光影图像对应的光照信息。结果表明:该方法能较准确地自动获取光影图像的特征值及实际光照信息,且程序运行稳定,避免了现有方法的不足。     

基于微观本义复原的人脸图像光照正规化

为解决变光照下人脸识别的识别率低,光照正规化算法复杂.不易实现的问题,提出一个新的光照正规化方法一微观本义复原,即通过微观邻域上像素本义特征的定义,将整体图像上变光照下的非线性灰度变化转化为微观邻域内的线性变化,一定程度上避免了包括图像自身结构在内的不确定因素对图像复原的不利影响;并以邻域内的本义特征为光照不敏感特征,对本义特征进行结构编码,并用最小二乘法拟合编码值与光照方向之间的关系,最后根据得到的光照正规化参数复原图像.实验结果表明,该方法算法简单,易于实现,能适应实时的人脸识别系统,在光照变化90.以内的Yale B库的平均识别率可达94.1%.     

对数域中基于实例学习的光照估计

复杂和多光照场景下的光照估计是颜色恒常性计算的难点和热点。提出一种对数域中基于实例学习的光照估计方法。通过分析光照对图像色度的影响,提取对数色度直方图作为光照一致性特征,在实例学习框架下,根据特征相似的已知光照实例估计目标场景光照。算法分割原始图像为多个光照均匀场景,分区域估计局部光照,并融合得到整幅图像的全局光照信息。在多组单光照和多光照数据集上的实验结果表明,相较于其他先进方法,本文方法在不同数据集上的光照估计误差中位数降低了5%~14%,精度更高且稳健性更好。     

彩色数字相机快速自动曝光方法EI北大核心CSCD

彩色数字相机的曝光准确度直接影响了图像的色彩表现及人眼视觉的感受效果。提出了一种基于人眼视觉感观特性的相机自动曝光方法。通过对图像清晰度、色彩饱和度以及亮度等因素的客观评价,建立了曝光估计函数。根据统计原理并结合经验公式,对曝光估计值与曝光步长增量之间的函数关系进行标定,确立了曝光增量函数。根据当前帧图像的不同亮度属性,结合曝光增量函数,实时计算下一帧所需要的理想曝光值。大量实验表明,该方法对于不同场景、不同光照条件下图像的曝光量都有良好的调节效果,稳健性较强并具有较高的调节效率。     

融合暗通道先验和MSRCR的分块调节图像增强算法

针对雾霾天气图像中雾霾浓度分布不均以及色彩失衡等问题,提出一种将暗通道先验算法与带色彩恢复因子的多尺度Retinex算法相结合的分块调节图像增强算法.对大气散射模型以Retinex图像模型中的尺度进行线性映射,得到一个同时具有大气散射模型中的透射率和大气光照值以及Retinex图像模型中入射图像的多参数新模型.根据模型获取去除大气散射图的新原图,并利用不同尺度的引导滤波计算获得整幅图像的入射图像,再结合大气散射光图以及色彩恢复因子得到最终的高频细节图.针对图像中雾霾浓度分布不均的情况将整图划分为多个区域小块,用融合后的算法计算每个区域小块的动态截断值,根据不同的动态截断值可以对整幅图像的高频细节进行动态调整,从而得到多幅局部最优图像,将得到的图像进行像素级等权融合,最后可得到保证各局部细节的最优图像.将本文算法与现有算法在主观视觉和客观评价两方面进行了实验对比,结果表明,该方法可以有效解决图像雾气不均匀以及色彩失衡等问题,明显提高了去雾后图片的质量.     

光照强度对太阳能电池特性影响的实验研究

为研究光照强度对太阳能电池特性的影响,以改变光照距离的方法收集了相关数据,对太阳能电池的特性作了初步的分析和讨论,得出了太阳能电池开路电压、短路电流、内阻、最大输出功率、最佳负载电阻及填充因子与光照强度的关系,且发现一定光照下最佳负载电阻低于该光照下太阳能电池的内阻。     

秦始皇陵三号坑兵马俑的指纹元素散布分析

为研究秦始皇兵马俑三号坑原料产地,选取秦始皇三号坑的陶俑和陶马样品42个,秦始皇兵马俑博物馆附近粘土样品20个,用中子活化分析测量样品中32种微量元素的含量,从这32个元素中挑选出8种指纹元素的含量进行散布分析.结果表明三号坑兵马俑样品与秦始皇陵附近的垆土关系密切,与黄土关系稍远.由此推断,三号坑兵马俑的原料来源可能是骊山地区的粘土,烧制兵马俑的窑址也可能在秦始皇陵附近. Terracotta warriors and horses of Qin Shihuang s Mausoleum is famous in the world, but their original place of raw material is still a riddle up to now. 42 samples of pottery warriors and horses of Qin Shihuang s Mausoleum in pit No.3, 20 samples of clay nearby Museum of the terracotta warriors and horses of Qin Shihuang s Mausoleum are selected and prepared for analysis. The contents of 32 microelement are measured by neutron activation analysis (NAA), the eight elements are chosen as the...     

徐州西汉陶漆的红外光谱分析

将家兔和胎儿的鞘外无滑膜肌腱段分别放入膝关节腔内进行在体肌腱培养和体外与滑膜细胞联合培养。结果显示；在体培养的肌腱段表面出现了光滑的，具有滑膜组织形态结构的特征，游离于关节腔内，无粘连发生；体外与滑膜细胞联合培养的胎儿肌腱段表面，被滑膜细胞爬行并覆盖。实验表明：无滑膜肌腱在滑液环境中可向有滑膜肌腱转化，并且可以通过体外培养进行滑膜化改造，使之滑膜化。     

新石器时期西山遗址古陶器表面陶彩的分析及其与烧结温度的关系

本文应用Ｘ射线衍射仪和Ｘ光荧光光谱仪，对新石器时期河南西山遗址出土的古陶器表面的陶彩进行了分析，根据分析结果初步推断出当时陶器的烧结温度     

庙底沟遗址出土仰韶文化彩陶的科学研究

彩陶文化作为新石器时期的重大发明,改变了远古先民的审美方式,而著名的仰韶文化以其彩陶的优美造型、绚丽色彩和丰富的纹饰揭示了原始的艺术特征,承载了史前时期重要的社会文化信息。而利用现代光谱分析技术准确、无损和微损的特点,可以为文物保护的研究提供更科学的技术支撑。研究应用相位辅助光学三维扫描、多光谱成像、X射线荧光、激光拉曼光谱分析技术,对河南省陕县庙底沟遗址出土的新石器时代晚期仰韶文化彩陶碗进行面、点相结合的综合分析,获得了较为完整的文物物理和化学信息。利用三维扫描技术所构建的彩陶碗数字化模型对样品进行了几何尺寸的非接触测量和虚拟修复,利用多光谱成像技术所获得的灰度图像对样品表面化学特征相似区域进行了区分,结合X射线荧光和激光拉曼光谱分析技术对彩陶残片的分析结果,确定了所分析彩陶样品的主要化学成分特征和颜料物相组成。综合研究结果,提出了建立彩陶文物多源信息数字化模型的构想,为这类文物的数字化保护和展示提供了基础科学信息。     

A review of Mössbauer spectroscopic studies of ancient pottery

Mössbauer spectroscopy has proven itself to be invaluable to archaeologists by providing a means to classify pottery and to provide information on particular providences for various ancient pottery finds. The original firing atmosphere can often by deduced from the ratio of Fe²⁺ to Fe³⁺. The change in the quadrupole splitting and the magnetic hyperfine splittings allow for the determination of the original firing temperatures. Ancient pottery samples from many cultures have been studied and a number of general conclusions are possible.     

Provenance identification of ancient pottery from Hachijojima Island,part of Izu Islands (Tokyo,Japan), using X-ray fluorescence spectrometry

A total of 47 pottery fragments were unearthed in Hachijojima Island, part of the Izu Islands (Tokyo, Japan). Among these samples, 36 found in the Kurawa site had designs resembling pottery dating back to the Jomon period (14,000–300 BC) distributed throughout Japan's main island, Honshu; five samples from the Jomon period found in the Yubama site were “undesigned”; the rest, found in the Yaene site, were undesigned Haji pottery samples dating back to the beginning of the late Kofun period (490–549 AD). X-ray fluorescence spectrometry (XRF) was used to determine the chemical composition (in terms of 10 major oxides and 12 minor elements) of the samples to identify their provenance, that is, local versus nonlocal. For this purpose, a portion of each pottery fragment was processed to obtain a glass bead specimen. The pottery samples were classified by multivariate statistical approaches, including principal component analysis and cluster analysis, on the basis of their chemical composition. Additionally, the XRF results were compared to geochemical data from Hachijojima Island using scatter diagrams. The data thus collected allowed the provenance of the pottery samples to be inferred. In particular, the 36 samples from the Kurawa site were concluded to have been brought to Hachijojima Island from Honshu in prehistoric times, whereas the other samples were concluded to have been manufactured locally.     

Jomon pottery observed from the point of view of fluid mechanics

It is said that the Jomon period began about 12,000 years ago and continued till about 2,500 years ago. The potteries of that age are known as Jomon pottery. Among them, a pottery discovered from the Umataka ruin in Niigata Prefecture in 1931 has an excellent shape. It is said that this pottery was made about 4,500 years ago. Jomon potteries of similar artistic styles have been discovered in various parts in Japan. These potteries have very nice shapes, but the pottery discovered from the Umataka ruin excels other potteries in its excellent proportion. From the shape of lip, it was named “Kaen pottery” meaning “Flame potter”. However, from the patterns of its lip and side wall, it is more appropriate to consider that they are related to water flow. In this report, this hypothesis is made clear by a visualization method using the pollen of cedar and pine trees, and computer simulation.     

Technological features of ‘gnathia’ pottery

‘Gnathia’ pottery samples, dating back to the mid‐fourth and third century BC, from the archaeological site of Egnazia (Fasano, Brindisi, Italy) have been characterised from the physical‐chemical, mineralogical and morphological points of view. Optical and scanning electron microscopy, X‐ray energy‐dispersive spectroscopy and X‐ray diffraction analyses have been carried out on the ceramic body, black gloss, white, yellow and red over‐paintings of fragments, with the aim of outlining technological features and defining the nature of coatings and decorations. Analytical results confirm from both a technological and morphological/decorative point of view the close relationship between ‘Gnathia’ pottery and red figured pottery, particularly with the Apulian red figured from which it takes its inspiration. At the same time the experimental results highlight shared characteristics and differences with both Attic and Apulian red figured productions. The biggest difference is in the utilisation of the ‘ingobbio rosso’ layer that covers the ceramic body. This does not seem to be based on aesthetic grounds, as in the case of Apulian red figured pottery, but on application of acquired production processes, since ‘Gnathia’ pottery was made in the same workshops as red figured pottery. Copyright © 2009 John Wiley & Sons, Ltd.     

基于X射线谱学和操作链分析的煤山遗址出土陶器综合研究

采用能量色散X射线荧光光谱（ED-XRF）技术结合考古学常用的陶器操作链研究模式, 对河南汝州煤山遗址出土的陶器遗存开展制作工艺和文化传承关系的综合研究。煤山遗址位于河南省汝州市（原为临汝县）北刘庄村,是研究中原地区新石器时代向文明国家转变的代表性遗址,出土了龙山时代的王湾三期文化（BC2300-BC1900）和具备早期国家形态的二里头文化（BC1750-BC1500）两个重要阶段大量具有典型考古学文化特点的陶器遗存,可以据此较为深入理解距今4000年前后社会复杂化进程和国家起源等重大问题。因此,对该遗址出土陶器的多学科综合研究具有极高的学术价值和文化意义。对煤山遗址出土具有不同文化类型的陶器样本进行化学组成与物理性能分析,将分析结果与陶器操作链分析相结合,进行比对分析。针对煤山遗址陶器遗存,谱学分析结果显示,不同时期考古学文化在制陶原料的选择上差异不大,具有同源性,暗示虽然文化类型不同,但其对粘土的认识和选择具有高度一致性。陶器操作链分析结果显示,虽然新石器时代的王湾三期文化年代较早,但其陶器制作工艺却较晚期的二里头文化更先进,体现了中原地区文化演进过程中既连续又摇摆的发展特点。陶器操作链分析可以反映文化内容的特征性和继承性,在使用谱学分析排除了原料与烧制影响后,对其所提取的信息具有更强的说服力和可比性。综合研究表明,将谱学分析和陶器操作链分析相结合,开展多学科对比和综合研究,可以更好的排除干扰,获取更为扎实且客观的认识,并为考古学文化演进研究提供重要的科学依据。     

Application of various spectroscopic techniques to characterize the archaeological pottery excavated from Manaveli,Puducherry, India

This paper is focused on a spectroscopic study of some ancient pottery shreds from an archaeological site Manaveli village, Puducherry, India. Analytical characterization using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and differential scanning colorimetric coupled with thermo gravimetric analysis were carried out on red and black ware and red ware recently excavated from the above site. The experimental results of FT-IR and XRD are similar and allowed us to identify the mineralogical composition of pottery samples. In addition, TGA was applied in order to study the dehydration of hydroscopic water and decomposition of carboxyl group in the powdered pottery samples during heating. Moreover, this paper proves that all the above spectroscopic techniques are very useful analytical tool for the examination of ancient pottery, which is also suitable for the identification of its firing temperature and firing atmosphere.