基于机器视觉的低对比度纸病识别算法研究

利用机器视觉识别纸病时,若背景与目标纸病的对比度低,且采用单一的边缘检测算法,将会出现对目标纸病边缘定位不准确、抗噪性能不好等问题。对此,提出了一种解决方法,即首先分别用LOG算子和基于数学形态学的边缘检测方法对低对比度纸病图像进行边缘检测,然后对这两种边缘检测算法得到的图像进行小波融合,融合得到的图像中纸病边缘定位准确且具有一定的抗噪性,最后,对此进行了实验验证。研究结果表明,文中提出的解决方法可行,即可将该方法用于基于机器视觉的低对比度纸病识别。     

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。     

改进的阈值选取方法在纸病图像分割中的应用

全局阈值分割法对含有对比度不同的纸病图像分割效果差,把图像先分块再求阈值,可以分割出每块区域的目标。针对上述分割结果的不足,提出了一种改进的阈值选取方法,该方法是用改进的迭代法对分割的子块求阈值,最后与每块区域的平均灰度值作比较,找出整幅图像的最优阈值。以含有灰度不一污点的纸病图像为处理对象,实验结果表明改进的方法可以分割出低对比度纸病。     

基于粒子群优化算法与形态学的纸病图像检测方法

针对传统边缘检测算子对纸病图像检测的不足,提出了一种基于粒子群优化算法和数学形态学的边缘检测方法。首先通过粒子群优化算法得到图像最优分割阈值,将图像二值化,然后利用数学形态学中的腐蚀运算对纸病图像进行边缘检测。仿真结果表明,相比传统算法,该方法的检测结果更真实地反映了纸病图像的形态特征,且边缘定位准确,取得了较为理想的检测效果。     

基于Gabor滤波器的低对比度纸病检测算法

针对现有的纸病检测算法对裂痕、褶皱等低对比度纸病检出率低、抗干扰能力差的问题,提出一种基于Gabor滤波器的纸病检测算法。首先使用Gabor滤波器以及Gaussian滤波器去除纸张纹理干扰,增强纸病区域对比度;然后使用Laplasian算法进行边缘检测,最后使用形态学闭运算得到完整的纸病边缘图像。实验结果表明,该算法对低对比度纸病检测正确率高,并具有良好的抗干扰性能。     

基于改进型canny算子的跑道边缘检测与识别方法

文章介绍了一种基于改进型canny边缘检测算法的跑道边缘检测与识别方法,主要应用于无人机自主着陆视觉导航技术领域。本方法对拍摄的跑道图像进行采集,得到数字图像,进行预处理,对处理后的图像采用文章提出的一种改进型的基于四阈值的canny边缘检测方法进行边缘检测,并对检测出的图像边缘进行识别,最终给出边界描述。     

基于Hough变换的纸病检测分析

褶子是纸病的一种,通常采用对纸病图像进行预处理、阈值分割等常规方法来检测褶子,但常规方法对不连续的褶子检测效果不是很明显,本研究提出了一种基于Hough变换的褶子检测方法.     

边缘检测在纸病图像分析中的应用

边缘检测是纸病图像处理的重要方法,也是各类纸病识别的前提。选取孔洞、脏点和褶皱三种有代表性的纸病为研究对象,通过C++编程探究了Roberts算子、Sobel算子和Prewitt算子在纸病图像检测中的效果。通过研究发现,Prewitt算子可以很好地检测出同时含有孔洞、脏点和褶皱的纸病图像的边缘,并且识别率在93.8%以上。为纸病识别的进一步研究奠定了基础。     

基于多尺度图像增强结合卷积神经网络的纸病识别分类

针对造纸工业中传统纸病识别分类依赖于特征描述子和分类器的选择问题,提出一种多尺度图像增强结合卷积神经网络的纸病识别分类方法。该方法利用多尺度形态学梯度增强纸病图像的边缘轮廓信息,突出缺陷梯度特征,然后利用卷积神经网络(CNN)学习纸病图像的特征并分类识别,从而实现纸病的准确识别分类。实验结果表明,该方法对纸病识别分类的结果明显优于HOG+SVM、LBP+SVM以及传统CNN方法,在Caltech101、KTH-TIPS以及本课题的数据集上的分类正确识别率分别达到98.44%、99.23%和99.64%。与现有纸病识别分类方法相比,本课题方法不需针对各种纸病进行缺陷特征提取和特征描述,能快速实现纸病的准确识别分类。     

基于Prewitt算子与形态学的纸病图像检测方法

针对Prewitt算子在检测中存在的边缘不连续性的问题,提出一种基于Prewitt算子和数学形态学的纸病图像边缘检测方法。首先利用Prewitt算子对纸病图像进行处理,然后将处理后的图像进行形态学的闭运算。实验表明,该方法结合了两种检测方法的优点,有效地提高了边缘检测的准确性,得到了比较理想的纸病边缘检测效果。     

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.     

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.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press