ISO_IEC_TR_29158-2011.pdf

TECHNICALISO/IECREPORTTR29158First edition2011-10-15Information technology-Automaticidentification and data capturetechniques-Direct Part Mark(DPM)Quality GuidelineTechnologies de Iinformation-Techniques automatiquesdidentification et de capture de donnees-Ligne directrice de qualitedu marquage direct sur piece(DPM)Reference number1S0/1ECTR29158:2011(E)ISOIECIS0/1EC2011IS0/IEC TR29158:2011(E)COPYRIGHT PROTECTED DOCUMENTIS0/1EC2011All rights reserved.Unless otherwise specified,no part of this publication may be reproduced or utilized in any form or by any means,electronic or mechanical,including photocopying and microfilm,without permission in writing from either ISO at the address below orISOs member body in the country of the requester.ISO copyright officeCase postale 56.CH-1211 Geneva 20Tel.+41227490111Fax+41227490947E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandISO/IEC 2011-All rights reservedIS0/1ECTR29158:2011(E)ContentsPageForewordVIntroduction.V1.12Normative references.13Terms and definitions.14Abbreviated terms.25Overview of methodology.35.1Process differences from 15415.5.2Lighting.3.36Obtaining the image.6.13Orientation of the symbol to the camera.36.2Lightinge.46.3Image focus.46.4Reflectance calibration.46.5Initial image reflectance level of the symbol under test.5Obtaining the test image.57.1Binarize image.7.2Apply Reference Decode Algorithm.5.57.3Connect areas of the same colour.67.4Final image adjustment.78Determine contrast parameters.78.1Calculate Cell Contrast(CC).88.2Calculate cell Modulation(CM).88.3Calculate Reflectance of Symbol(Rtarget)89.81Cell Contrast(CC).89.2Minimum Reflectance.89.3Cel Modulation CM)89.4Fixed pattern damage99.5Final grade.910Communicating grade requirements and results.10.1Communication from Application to Verifier.9910.2Communicating from Verifier to Application.910.3Communicating Lighting.910.4Communicating the use of a proprietary decode.10Annex A(normative)Threshold determination method.11Annex B(informative)Communicating the grade.15Annex C(informative)Cross-reference to ISO/IEC 15415.18ISO/IEC 2011-All rights reserved必IS0/1ECTR29158:2011(E)ForewordISO(the International Organization for Standardization)and IEC(the International ElectrotechnicalCommission)form the specialized system for worldwide standardization.National bodies that are members ofSO or IEC participate in the development of International Standards through technical committeesestablished by the respective organization to deal with particular fields of technical activity.ISO and IECtechnical committees collaborate in fields of mutual interest.Other international organizations,governmentaland non-governmental,in liaison with ISO and IEC,also take part in the work.In the field of informationtechnology,ISO and IEC have established a joint technical committee,ISO/IEC JTC 1.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives,Part 2.The main task of the joint technical committee is to prepare International Standards.Draft InternationalStandards adopted by the joint technical committee are circulated to national bodies for voting.Publication asan International Standard requires approval by at least 75%of the national bodies casting a vote.In exceptional circumstances,when the joint technical committee has collected data of a different kind fromthat which is normally published as an International Standard(state of the art,for example)it may decide topublish a Technical Report.A Technical Report is entirely informative in nature and shall be subject to reviewevery five years in the same manner as an International Standard.Attention is drawn to the possibility that some of the elements of this document may be the subject of patentrights.ISO and IEC shall not be held responsible for identifying any or all such patent rights.ISO/IEC TR 29158 was prepared jointly by Joint Technical Committee ISO/IEC JTC 1,Information technology,Subcommittee SC 31.Automatic identification and data capture techniques.么ISO/IEC 2011-All rights reservedIS0/1ECTR29158:2011(E)IntroductionDirect Part Marking(DPM)is a technology whereby,generally,an item is physically altered to produce twodifferent surface conditions.This alteration can be accomplished by various means including,but not limited to.dot peen,laser,ink jet,and electro-chemical etch.The area of the alteration is called the mark.The area thatincludes the mark and background as a whole,when containing a pattern defined by a bar code symbologyspecification,is called a symbol.When light illuminates a symbol,it reflects differently depending on whether it impinges on the background ofthe part or on the physical alteration.In most non-DPM bar code scanning environments,light is reflected off asmooth surface that has been coloured to produce two different diffuse reflected states.The DPMenvironment generally does not fit this model because the two different reflected states depend on at leastone of the states having material oriented to the lighting such that the angle of incidence is equal to the angleof reflection.Sometimes the material so oriented produces a specular(mirror-like)reflectance that results in asignal that is orders of magnitude greater than the signal from diffuse reflectanceIn addition,from the scanner point-of-view,some marking and printing methods generate dots and are notcapable of producing smooth lines.Current specifications for matrix symbologies and two-dimensional print quality are not exactly suited toreading situations that have either specular reflection or unconnected dots or both.This is intended to act as abridge between the existing specifications and the DPM environment in order to provide a standardizedimage-based measurement method for DPM that is predictive of scanner performance.As with all symbology and quality standards,it is the responsibility of the applicator to define the appropriateparameters of this guideline for use in conjunction with a particular application.ISO/IEC 2011-All rights reserved