翻訳と辞書 Words near each other ・ Void (film) ・ Void (law) ・ Void (Vanna album) ・ VOID (Video Overview in Deceleration) ・ Void coefficient ・ Void contract ・ Void Cube ・ Void deck ・ Void Dweller ・ Void galaxy ・ Void Indigo ・ Void Linux ・ Void marriage ・ Void Moon ・ Void of Silence ・ Void pantograph ・ Void ratio ・ Void safety ・ Void Server ・ Void Terra Firma ・ Void Trilogy ・ Void type ・ Void-Vacon ・ Voidable ・ Voidable contract ・ Voidable floating charge ・ Voidable marriage ・ Voidable marriages (Australia) ・ Voided biaxial slab ・ Voiding cystourethrogram Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Void pantograph ： ウィキペディア英語版 Void pantograph In security printing, void pantograph refers to a method of making copy-evident and tamper-resistant patterns in the background of a document. Normally these are invisible to the eye, but become obvious when the document is photocopied. Typically they spell out "void", "copy", "invalid" or some other indicator message.〔Jason S. Aronoff, Steven J. Simske, Margaret Sturgill. Automated Optimization of Void Pantograph Settings. HP Laboratories HPL-2011-179 http://www.hpl.hp.com/techreports/2011/HPL-2011-179.pdf〕 Void pantographs work by exploiting the limitations and features of copying equipment. A scanner or photocopier will act as a low-pass filter on the original image, blurring edges slightly. It will also not be perfectly aligned with the directions of the document, causing aliasing. Features smaller than the resolution will also not be reproduced. In addition, human vision is sensitive to luminance contrast ratio. This means that if a grey region consists of a grid of very small dark dots the filtering will produce a lighter grey, while a region of larger dots will be affected differently ("big-dot-little-dot"). This makes it possible to see a pattern that previously was invisible.〔〔J. Kim, K. Kim, J. Lee and J Choi, "Development of Visible Anticopy Patterns," in TrustBus 2004, LNCS 3184, pp. 209-218 (2004)〕 Numerous variations exist, including printing the marks using a raster of lines in one direction on a background of lines in another direction,〔John R. Volpe. Printing method and copy-evident secure document. US patent 5487567 http://www.google.com/patents/US5487567〕 or using fine line patterns that alias into a visible moire pattern when copied.〔George K. Phillips. New Digital Anti-Copy/Scan and Verification Technologies. In: Optical Security and Counterfeit Deterrence Techniques V, San Jose, California; June 3, 2004; p. 133-141; ISBN / ISSN: 0-8194-5213-0 http://www.verifyfirst.com/Documents/AntiCopy12-12-03.pdf〕 ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Void pantograph」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.