基于聚类的SAR图像灰度特征提取算法

SAR(合成孔径雷达)图像包含大量相干斑噪声,用传统灰度特征提取算法提取其灰度特征,不能有效反映地貌边缘特征和纹理细节,文中提出一种基于聚类的SAR图像灰度特征提取算法,有效保护了灰度特征中的边缘和纹理细节,实验结果表明,该算法提取的灰度特征值更能接近真实地貌。     

提高边缘细节清晰度的图像融合改进算法

为解决图像融合过程中边缘信息以及细节内容易于丢失的问题,提出图像融合的改进算法。对源图像进行小波变换分解,将分解后的高低频系数用矩阵存储。对于低频子带的系数,采用形态学边缘检测的方法,提取出边缘轮廓系数,后运用加权平均法对其进行融合得到用于重构的低频系数。对于各高频子带的系数,先采用区域能量法构造出判断矩阵,经多数筛选法和形态学处理后得到二值融合决策图,并根据此决策图选取出用于重构的高频系数。最后,进行图像重构得到融合图像。实验结果表明,该算法增强了图像边缘细节的清晰度,其图像融合效果在相同融合条件下比其它算法更好,熵、标准差和平均梯度等图像融合的评价指标提高了0.5%～5%,可以更有效地应用于医学或多聚焦图像的融合。     

马尔可夫随机场在纸病检测中的应用研究

纸病检测是造纸生产过程中重要的环节,现有的纸病检测系统一般采用阈值算法或边缘检测算法对图像进行分割。为解决阈值分割和边缘检测分割方式中存在的误分以及过度分割问题,本研究提出了基于马尔可夫（MarKov）随机场的纸病图像分割方法。通过MarKov随机场理论对纸病图像纹理进行分析得到纹理特征参数,利用纹理特征参数以及最大差值对正常背景和纸病区域进行分割。结果表明,相比于其他分割算法,基于MarKov随机场的纸病图像分割方法可有效提取出纸病图像的纹理细节和轮廓特征,提高分割的准确度。     

织物表面几何形状检测中最优边缘检测算法的选取

基于机器视觉方法检测织物表面图案几何形状,研究棉质纺织品表面图案边缘的检测效果,通过对比找到适合工业应用的边缘检测算法。选取多种典型的边缘检测算子为考察对象,首先对各自边缘检测的结果图像及其信息熵进行对比,然后分析各算子在目标区域分割、内部条纹及局部图案细节等多方面的表现,证明Sobel算子得到的图像边缘与背景区域的灰度差异明显,灰度信息熵最小,有利于图像几何信息的识别;而且Sobel算子对织物表面及背景区域的纹理不敏感,识别结果:图像中噪声及后续处理难度较小,适合棉质袜子表面几何形状的检测。     

基于图像融合的边缘提取新方法研究

提出一种基于数学形态学和Canny算子边缘提取的方法。传统的基于形态学的边缘提取方法有较好的去噪能力,其得到的信息往往不完整,不能反映图像全部的边缘信息。为了得到比较完整的图像边缘信息特征,利用数学形态学的方法和Canny算子方法先对图像分别进行边缘提取,然后将两种方法处理后的图像利用小波分解进行图像融合,实验结果表明,该方法得到的图像边界较细腻完整,且具有较好的抗噪性。     

基于数学形态学算法的纸病检测及IDL应用

本文介绍了采用数学形态学算法从纸样图像中提取纸病的方法。运用第四代计算机语言IDL（Interactive Data Language）完成了数学形态学的膨胀、腐蚀及梯度运算,并实现了纸样图像中纸病边缘的检测．结合阈值分割方法得到纸病检测和分割结果     

基于机器视觉激光切割自动寻边技术研究

论述了利用计算机视觉和图像处理技术实现激光切割机自动寻边切割的基本原理和实现方法.提出一种阈值滤波算法用于图像预处理,能在去除噪声的同时,较好地保留原图像的边缘信息.为了克服由于环境而导致的光强变化及物体表面粗糙度对物体图像边缘的影响,采用改进的边缘检测算法用于边缘信息的提取,通过设计一个梯度极值算子窗口,在窗口领域内直接对像素进行操作,来提取边界特征像素.用VC 6.0开发了整个系统的图像处理软件和系统控制软件,该方法对自动寻边切割具有计算简单、效率高、边缘提取准确的特点,已成功地应用于实际的自动寻边激光切割系统中.     

基于方差投影与相关系数的色织物密度检测

为提高色织物密度检测的准确性,提出了方差投影与相关系数相结合的色织物密度检测方法。首先,校正倾斜的织物图像并通过顶帽变换提高图像对比度,然后根据图像梯度检测水平和垂直方向上的边缘,增强边缘信息后提取其骨架,得到色织物不同颜色区域的分界线;最后,依据分界线坐标将图像分为若干个子图像,统计子图像方差投影与相关系数数据,从而计算出色织物密度。实验结果表明:此方法的平均误差率在0.4%以下,对色织物密度检测具有一定的应用价值。     

棉花叶部害螨病斑形态特征提取

针对当前农作物病害诊断存在的效率较低、难以保证精确度等问题,提出运用计算机图像处理技术进行棉花害螨病斑特征提取的方法.该方法以棉花害螨病叶为研究对象,利用中值滤波法对噪声的干扰进行有效的去除;结合运用超绿特征2G-R-B分割算法和面积阈值法将害螨病斑区域从病叶图像中有效分离出来;最后依据分割好的病斑样本图像,运用二值图像区域标记法准确提取出病斑的8个形状特征值.对提取的数据进行分析,得出病斑的圆形度、伸长度紧凑度和内切圆半径等4个相对值特征能有效地体现病斑的形状特征,可以作为识别病害症状的依据.试验结果表明,该方法准确有效.     

基于参数可调均值迁移滤波实现筒子纱的识别检测

为了提高机器视觉对纱筒图像识别检测的准确率,课题组提出了一种参数可调均值迁移滤波算法。在图像采样过程中,先对源图像进行锐化处理,再对图像空间窗口与颜色窗口同时进行卷积操作,筒子纱的边缘轮廓得到完整保留,且通过滤波处理去除图像噪声;采用Canny算子边缘检测,完成对筒子纱的轮廓提取;几何矩计算轮廓质心和横纵比过滤判别筒子纱的放置状态。实验结果表明:该方法在图像处理过程中准确、可靠,能够满足图像识别检测的要求。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Influence des ions sur le pouvoir hydratant de l'ure e: e tude sur peau de porc ex vivo

This study deals with the influence of ions (NaCl and MgSO4) in a W/O emulsion containing 10% urea. Moisturization kinetics are assessed by corneometry on pig skin ex vivo. The formula's influence on urea penetration is measured by infrared spectrometry with an ATR device and the stripping method. Corneometry and spectroscopy were chosen to record simultaneously the hydratation levels and urea localization into superficial cell layers. Urea crystallization after evaporation of emulsions and aqueous solutions is described. Results show that urea does not hydrate nor penetrate when applied to the skin through an aqueous gel. In a W/O emulsion, sodium chloride increases the ability of urea to moisturize without improving penetration. In vitro urea crystallization is disturbed by sodium chloride or magnesium sulphate for solutions and emulsions. This stabilization by ions is correlated with good moisturization values. The stabilization of urea in the solute state provided by ions increases its water epidermal binding capacity without enhancing penetration.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.