共查询到18条相似文献，搜索用时 171 毫秒
1.
2.
本文从光源作用于测试图极端阶调区域后对中性灰还原影响的角度测量了平板扫描仪的散射光效应，为此设计了置于黑色和白色背景的等距离分布灰色块测试图。实验结果表明，三种被测试的不同类型的平板扫描仪确实存在散射光效应。 相似文献
3.
4.
本文讨论在图像质量分析软件的支持下以平板扫描仪测量实地和平网填充区域反射密度的可能性。实验结果表明,只要选择合理的测量方法,则密度计与扫描仪密度测量数据间存在很强的相关性,意味着扫描仪测量的密度数据经补偿处理后与密度计测量数据等价。 相似文献
5.
7.
8.
从摄影的角度来看, 扫描仪相当于相机加胶片和冲洗。传统的扫描仪测试方法难以将扫描仪的性能做横向比较, 另外对扫描仪的清晰度测试往往只限于对黑白线条的分辨能力。传统摄影有比较完善的测试方法, 如对镜头的 MTF 测试, 对胶片的宽容度和色彩还原测试等等。由于测试项目直接与成像质量相关, 且具有横向的可比性, 因此对人们选择设备很有帮助。 我们参照上述方法设计了扫描仪的 3 项测试指标: 拟 MTF 测试扫描仪光学系统成像的明锐度、用 ISO IT8 色卡测试扫描仪的曝光宽容度和色彩还原。我们分别来看它的原理。 拟 MTF 测试（明锐… 相似文献
9.
10.
11.
大尺寸原稿数字化需要特殊类型的扫描仪,通常基于照相原理构成而成。本文测量和评价了照相原理扫描仪的空间频率响应和色彩还原能力,测量结果表明,扫描仪的水平分辨率低于制造商提供的数据。 相似文献
12.
本文从平板扫描仪的结构和信息捕获特点分析灰色再现误差的原因。两种平板扫描仪的灰色再现测量数据表明,中性灰捕获后灰度等级按红、绿、蓝次序升高,总体上EpsonGTX970的灰色再现精度要高于SeanMaker3850Ⅲ扫描仪。 相似文献
13.
本文简单地归纳和总结了数字半色调技术的发展历史.数字半色调起源于扫描和加网一体化的电分机,经逐步改善和提高后演变成现代数字半色调工艺.除数字半色调起源外,文章也涉及数字半色调的分类和现代数字半色调技术. 相似文献
14.
Sarah Elliott Rosa Longacre 《Journal of Interlibrary Loan, Document Delivery & Electronic Reserve》2013,23(1):43-51
The Document Delivery Services/Interlibrary Loan Unit and the Course Reserves Unit at the University of California, San Diego's Access Services Department both utilize the Konica Minolta PS7000 book scanner to deliver requested documents and post electronic reserve items. Though the hardware is the same in both units, unique service goals and software—Ariel Interlibrary Loan Document Transmission Software for DDS/ILL and Adobe Photoshop for Course Reserves—result in different issues and challenges. This article discusses the shared practices of the Document Delivery Services/Interlibrary Loan and Course Reserves Units and how each unit utilizes the Konica Minolta PS7000 book scanner to offer better service for their patrons. 相似文献
15.
ABSTRACTBoundary walls are neglected but important parts of historic urban environments, and they are often prone to serious deterioration. Understanding moisture and salt dynamics within boundary walls can help infer the causes and dynamics of deterioration. This investigation investigates the patterns of moisture, salt, and deterioration on a 300 year old limestone boundary wall in Worcester College, Oxford. Multiple methods to assess moisture and salts within and across the wall (electrical resistivity tomography, handheld resistivity-based moisture meter, paper pulp poultices, scanning electron microscopy, inductively coupled plasma optical emission spectrometry, and ion chromatography of small scale sampling of deteriorated limestone) were used in conjunction with decay mapping of both sides of the wall. The salt weathering strongly correlates with severely weathered zones at the wall and salts, mainly sulfates, seem to be the main agent of decay processes. The combined results demonstrate that the environmental influences driving stone decay can differ on a very small scale even at a comparatively simple structure like a boundary wall, and that repairs can have adverse effects if the patterns of salt and moisture dynamics are not sufficiently known. 相似文献
16.
Hollie Smith Brianne Suldovsky Laura Lindenfeld 《Journal of Applied Communication Research》2016,44(1):78-95
Boundary theory has assumed that two distinct organizations—scientists and policy-makers—can interface with one another via an external boundary organization, yet boundary management contexts often call for different strategies where a neutral third party is not involved. Recent scholarship has highlighted alternative models for boundary organizations, including the emergence of boundary organizations within universities. Most of these studies have taken an organizational perspective, yet as universities increasingly fulfill the role of boundary organizations by direct engagement with policy-makers, we need a deeper understanding of the roles scientists should play within this context. This study highlights the need to understand context before designing and implementing boundary management strategies, and considers the complexities of direct engagement between scientists and policy-makers. We draw from a case study conducted in Maine to argue that there are contexts in which scientists need to manage and span the science–policy boundary. The complexities involved in preparing scientists to engage more thoroughly in policy activities and the challenges in garnering institutional support for advancing the participation of scientists in boundary-spanning activities are explored. 相似文献
17.
信噪比用于衡量数字成像系统的性能,为此需要计算成像系统的信噪比,并了解信噪比的计量单位。由于数字照相机和扫描仪的动态范围与噪声有关,因而测量数字成像设备的动态范围时应该考虑噪声,这使得信噪比增量法在测量动态范围时有了用武之地。 相似文献
18.
《Government Information Quarterly》2023,40(1):101777
On the path to creating digital platforms, governments are opening organizational boundaries to cultivate cross-agency collaboration in public service innovation. This collaborative innovation takes place in the context of paradoxical tensions between openness and closeness, stability and flexibility, and generativity and control. The concept of boundary resources provides an instrument to balance these platform design paradoxes. Yet, little is known about designing boundary resources in digital government platforms. We contextualize the concept of boundary resources in digital government platforms to develop design theories. These design theories guide an action design research, where a national tax service platform was redesigned to enable cross-agency collaboration for service innovation. Design knowledge was thus generated into three design principles for the design of boundary resources in government platforms. These principles help in making design decisions by which government platform owners use different boundary resources to address the three paradoxes. We suggest that government platform owners cultivate collaborative platform ecosystems and define unified data standards to address the openness, design data modularity and interfaces for resourcing complementors, and use data relationships and accessibility as control points for securing the platform. 相似文献