纸张性能对不同阶调处印刷品密度的影响

实验结合印刷品质量检测方法和SPSS软件,对在IGT印刷适性仪上的印刷结果进行分析,得到纸张性能与不同阶调处印刷品密度之间的关系.据此数据能够预知密度再现质量情况,可通过比较不同纸张的性能数据判断哪种纸张适合于目标印刷品.     

印刷品质量的模糊综合评价

<正>印刷品质量评价、检测或认定是印刷行业至关重要的管理工作。如何把印刷品质量的主观因素与客观评价有机地结合起来,进行科学的评价,是印刷行业管理人员、技术人员、质检人员探索之重要课题。用模糊数学的理论与现代印刷质量检测技术及经验相结合,建立印刷品质量综合评价管理系统的数学模型,为印刷行业打开了新的思路。     

关于第二届“上海印刷大奖”评选活动的通知

上海市各印刷企业、印刷品质量检测站和有关单位： 2006年；我们成功地举办了第一届“上海印刷大奖”评选活动，对印刷企业间技术质量交流和印刷品质量的提高起到了很好的推进作用，为进一步促进上海印刷产业健康持续发展，鼓励印刷企业不断提高印刷品的质量水平，实现上海印刷产业“十一五”发展战略目标，     

基于GATF星标的计算机印品质量控制系统

在高速印刷机上高效地控制印刷品的质量,是印刷工艺中的关键技术.传统方法通过目测进行控制,但难以及时检测印刷品状态.本文旨在研究GATF星标特性的基础上,以GATF星标为印刷品质量控制对象,通过摄像头获取GATF星标图像后,再对图像进行匹配和对比,判断印刷品质量,并对检测信息进行反馈,建立一套计算控制印刷品质量系统.     

如何评价彩印的质量

由于彩色印刷品具有一定的直观艺术效果，所以，对“彩色印刷品质量”（以下简称“印刷品质量旬的评价与对其它产品质量的评价有很大不同。印刷品质量评价除涉及客观因素外，还与人们的主观心理因素有关。这就增加了评价的难度。印刷品质量是制版质量与印刷质量的综合反映，所以，评价印刷质量的优劣，只能从工艺技术的角度考虑。因为，无论从印刷品的商业价值、社会效益、直视艺术效果哪方面考虑，都不能对印刷品质量的整体水平进行准确地评价。CY／T5－91《平版印刷品质量要求与检验方法》（以下简称《标准》）就是评价印刷品质量的依据…     

印刷透印标准的研究

分析了印刷透印产生的成因及对印刷品质量的影响,讨论了密度检测法、色度检测法及渗透深度计算法这3种印刷透印检测评价方法的优缺点,提出了使用色度检测法作为印刷透印的检测评价方法,为印刷透印技术标准的建立提供了参考指标.     

纸张特性对印刷品质量的影响

本从印刷品光泽、印刷图像的阶调再现、网点增大、纸张含水量等方面讨论了纸张特性对印刷品质量的影响，以此为印刷工作合理选择纸张、适当调整工艺参数来提高印刷品质量提供了参考。     

基于空间频率响应的印刷品清晰度检测

利用CCD 图像捕获设备,把印刷测试图转换为数字图像,采用基于倾斜边缘梯度分析的空间频率响应检测算法,测量获得了印刷复制系统的空间频率响应特性,并把经过人眼视觉系统滤波后得到的空间频率响应曲线内的面积作归一化处理后,所获得的测量值作为清晰度质量描述因子。实验结果表明,清晰度质量描述因子能较好地反映印刷品的清晰度复制质量,提供了一种新的客观、定量检测印刷品清晰度的方法,为实现印刷品质量的自动化检测与评价提供了有力的技术支持。     

纸张性能对纸张呈现色彩能力的影响

主要是进行纸张的传统印刷色域实验和数字印刷色域实验,并进一步分析纸张性能在传统印刷和数字印刷中对纸张色域的影响.这样印刷厂可以根据印刷品的质量要求尽快的确定适合目标印刷品的纸张.     

塑料包装薄膜印刷的光泽化处理

塑料包装薄膜一般都要在表面进行印刷，而塑料薄膜表面印刷质量，除了印刷的牢度，即：油墨在制品表面的附着力外，光泽性也是一个重要的指标。为了使印刷品表面有良好的光泽性，一般在表面印刷后，还应当对印刷品的表面进行光泽化处理。     

Statistical process monitoring via image data using wavelets

Image data plays an important role in manufacturing and service industries because each image can provide a huge set of data points in just few seconds with relatively low cost. Enhancement of machine vision systems during the time has led to higher quality images, and the use of statistical methods can help to analyze the data extracted from such images efficiently. It is not efficient from time and cost point of views to use every single pixel in an image to monitor a process or product performance effectively. In recent years, some methods are proposed to deal with image data. These methods are mainly applied for separation of nonconforming items from conforming ones, and they are rarely applied to monitor process capability or performance. In this paper, a nonparametric regression method using wavelet basis function is developed to extract features from gray scale image data. The extracted features are monitored over time to detect process out‐of‐control conditions using a generalized likelihood ratio control chart. The proposed approach can also be applied to find change point and fault location simultaneously. Several numerical examples are used to evaluate performance of the proposed method. Results indicate suitable performance of the proposed method in detecting out‐of‐control conditions and providing precise diagnostic information. Results also illustrate suitable performance of our proposed method in comparison with a competitive approach.     

Scanning and surface alignment considerations in chemical imaging with desorption electrospray mass spectrometry

The effects of surface scanning mode (raster vs unidirectional scanning) and the constancy of spray tip-to-surface and atmospheric sampling interface capillary-to-surface distances on chemical image quality using desorption electrospray ionization mass spectrometry were investigated. Unidirectional scanning was found to provide a spatially and a quantitatively more precise chemical image of the surface as compared to raster scanning. Maintaining constant spray tip-to-surface and atmospheric sampling interface capillary-to-surface distances during an imaging experiment was found to also be critical. An automation process was implemented using a custom image analysis software (HandsFree Surface Analysis) to keep these distances constant during the surface sampling experiment. Improved chemical image quality afforded through this software control was illustrated by imaging printed objects on normal copy paper.     

Influence of luminance and resolution on the perceived quality of black-and-white images on soft displays

Abstract

The perceived quality of an image displayed on a computer monitor depends on a number of different factors that can affect viewers' preferences. Two of these are the luminance of the monitor display and the resolution of the image. The effect of luminance is of interest for applications such as on-line access of images where the computer displays used for viewing these images could have different luminance settings. A relationship between cathode-ray tube (CRT) display luminance and resolution has been shown in previous studies. It was therefore interesting to investigate whether there is a relationship between image resolution and CRT display luminance on perceived image quality. Image resolution is related to the image file size, which is an important factor for applications such as on-line access of images. This work used a CRT display to study the effect of the above-mentioned factors on the perceived quality of the displayed image. Three sets of black-and-white images, each set with a different resolution, were presented to observers at three brightness settings of the computer monitor. Results are discussed regarding the effect of monitor display luminance and image resolution on perceived image quality and the interaction between them. Evaluation of results is further extended to the influence of the different backgrounds of the images. The scene content of the images was also shown to affect the viewers' judgement.     

基于机器视觉的商品条码质量检测方法

目的针对EAN-13商品条码,运用机器视觉技术进行商品条码质量检测,实现一体化、自动化、智能化检验。方法根据检测要求,设计商品条码图像采集装置,通过系统标定完成初始化。条码检测时,采集待测条码图像,进行畸变矫正;通过边缘检测、形态处理和轮廓匹配,找到条码准确位置,分割出条码图像区域,对其旋转校正,分为条码区域和数字区域;对条码区域,水平采样获取反射曲线,计算光学特性参数和译码数据,通过几何特征分析,结合标定参数,计算出相关结构参数;对数字区域,通过字符分割、模版匹配,完成字符识别;最后,通过比对分析,获取全部检测数据。结果分别采用该方法和传统方法,对100个EAN-13条码样本进行了检测对比,试验表明该方法的检验结果符合国家标准,检测数据准确可靠;该方法操作快捷,精度更高,检测速度大幅提高。结论文中方法实现了商品条码质量检测的一体化、自动化、智能化处理,显著提高了检验水平和工作效率。     

三维尺寸视觉测量系统

视觉测量技术是一种先进的非接触测量手段,具有系统组成灵活、工作空间大、精度合适、自动化程度高等特点,非常适合工业现场的在线测量与质量监控。本文分析视觉测量的原理及视觉测量系统的组成,研究了一个实际的视觉测量系统。     

An Empirical Indicator of Product Appearance for Process Control

An innovative approach based on multiattribute utility theory and group processes was used to directly monitor and control cosmetic characteristics affecting product appearance to improve the quality of a product. The main advantage of this approach is its ability to provide a direct and reliable measure of visual appearance for products for which this is the critical quality characteristic. The paper is divided into two main parts. The first part briefly presents a systematic approach to develop an empirical indicator of product appearance, called the index of visual condition (IOVC). The second part presents a study of the applicability of the IOVC during process control to directly monitor and improve product appearance. This study was performed during industrial production of a ceramic product for a period of seven months. Several Shewhart charts were developed, including the first exploratory X-bar and R charts for product appearance (IOVC charts) and c-charts for number of defects. The performance of these charts was evaluated by their ability to detect special causes of variation and improve the product. The case study indicates that these two approaches complement each other. While the c-chart allows one to monitor the number of defects that impair product functionality, the IOVC chart brings a new level of capability, providing the ability to directly monitor product appearance considering defects that do not affect functionality. Both approaches were useful for process control and improvement.     

水质自动监测站仪器运行分析测试

文章对闽江白岩潭水质自动监测站所用的在线分析仪器,从仪器的检出限、工作曲线、准确度、精密度等方面进行校验,将其分析方法与国家标准分析方法进行对比,结果是白岩潭水质自动监测站的自动监测方法可以满足闽江水质污染的监测,各项仪器检测方法与手工分析方法等效。     

振动信号短时功率谱时-频二维特征提取方法及应用

提出了一种基于图像处理技术的信号短时功率谱时一频二维特征提取方法，构造了一组对早期故障比较敏感的无量纲特征指标βm，δx和δ∑。理论分析和应用实例表明：这些特征参数比较全面地反映了信号中早期异常冲击成分的酝酿和发展，可有效地应用于旋转机械状态监测。     

一种基于图像处理的输电线路覆冰监测方法

在电力系统中,输电线路的覆冰现象非常普遍.严重的覆冰情况会造成巨大的经济损失和不良的社会影响.针对现有输电线路覆冰厚度的检测方法的不足,提出了一种基于图像处理的输电线路覆冰的监测方法,并详细介绍了其实现方式.该系统通过摄像机采集覆冰图像,进而对图像进行边界检测处理,测量出覆冰厚度;覆冰图像及覆冰厚度通过GPRS无线传输方式发送到监控中心,由监控人员做出相应的处理.实验表明,该监测系统能够实现输电线路覆冰的在线监测,且性能稳定,精度较高,具有广阔的应用前景.