1、Designation:E200710Standard Guide forComputed Radiography1This standard is issued under the fixed designation E2007;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year
2、of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide provides general tutorial information regard-ing the fundamental and physical principles of computedradiography(CR),definitions and terminology required tounderstand the
3、 basic CR process.An introduction to some ofthe limitations that are typically encountered during the estab-lishment of techniques and basic image processing methods arealso provided.This guide does not provide specific techniquesor acceptance criteria for specific end-user inspection applica-tions.
4、Information presented within this guide may be useful inconjunction with those standards of 1.2.1.2 CR techniques for general inspection applications maybe found in Practice E2033.Technical qualification attributesfor CR systems may be found in Practice E2445.Criteria forclassification of CR system
5、technical performance levels maybe found in Practice E2446.Reference Images StandardsE2422,E2660,and E2669 contain digital reference acceptanceillustrations.1.3 The values stated in SI units are to be regarded as thestandard.The inch-pound units given in parentheses are forinformation only.1.4 This
6、standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 A
7、STM Standards:2E94 Guide for Radiographic ExaminationE746 Practice for Determining Relative Image Quality Re-sponse of Industrial Radiographic Imaging SystemsE747 Practice for Design,Manufacture and Material Group-ing Classification of Wire Image Quality Indicators(IQI)Used for RadiologyE1025 Practi
8、ce for Design,Manufacture,and MaterialGrouping Classification of Hole-Type Image Quality In-dicators(IQI)Used for RadiologyE1316 Terminology for Nondestructive ExaminationsE1453 Guide for Storage of Magnetic Tape Media thatContains Analog or Digital Radioscopic DataE2002 Practice for Determining Tot
9、al Image Unsharpness inRadiologyE2033 Practice for Computed Radiology(PhotostimulableLuminescence Method)E2339 Practice for Digital Imaging and Communication inNondestructive Evaluation(DICONDE)E2422 Digital Reference Images for Inspection of Alumi-num CastingsE2445 Practice for Performance Evaluati
10、on and Long-TermStability of Computed Radiography SystemsE2446 Practice for Classification of Computed RadiologySystemsE2660 Digital Reference Images for Investment Steel Cast-ings for Aerospace ApplicationsE2669 Digital Reference Images for Titanium Castings2.2 SMPTE Standard:RP-133 Specifications
11、for Medical Diagnostic Imaging TestPattern for Television Monitors and Hard-Copy RecordingCameras33.Terminology3.1 Unless otherwise provided within this guide,terminol-ogy is in accordance with Terminology E1316.3.2 Definitions:3.2.1 aliasingartifacts that appear in an image when thespatial frequenc
12、y of the input is higher than the output iscapable of reproducing.This will often appear as jagged orstepped sections in a line or as moir patterns.3.2.2 basic spatial resolution(SRb)terminology used todescribe the smallest degree of visible detail within a digitalimage that is considered the effect
13、ive pixel size.1This guide is under the jurisdiction of ASTM Committee E07 on Nondestruc-tive Testing and is the direct responsibility of Subcommittee E07.01 on Radiology(X and Gamma)Method.Current edition approved June 1,2010.Published July 2010.Originally approvedin 1999.Last previous edition appr
14、oved in 2008 as E2007-08.DOI:10.1520/E2007-10.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from Soci
15、ety of Motion Picture and Television Engineers(SMPTE),3 Barker Ave,5th Floor,White Plains,NY 10601.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.2.1 DiscussionThe concept of basic spatial resolutioninvolves the ability to separate t
16、wo distinctly different imagefeatures from being perceived as a single image feature.Whentwo identical image features are determined minimally distinct,the single image feature is considered the effective pixel size.If the physical sizes of the two distinct features are known,forexample,widths of two parallel lines or bars with an includedspace equal to one line or bar,then the effective pixel size isconsidered12of their sums.Example:A digital image isdetermined to resolve five line pairs per mm