《BS-ISO-21550-2004.pdf》由会员分享，可在线阅读，更多相关《BS-ISO-21550-2004.pdf（24页珍藏版）》请在三一文库上搜索。
1、BRITISH STANDARD BS ISO 21550:2004 Photography Electronic scanners for photographic images Dynamic range measurements ICS 37.040.10 ? Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 13:22:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS ISO 21550:2004 This British Standard was published under
2、 the authority of the Standards Policy and Strategy Committee on 30 September 2004 BSI 30 September 2004 ISBN 0 580 44528 3 National foreword This British Standard reproduces verbatim ISO 21550:2004 and implements it as the UK national standard. The UK participation in its preparation was entrusted
3、to Technical Committee CPW/42, Photography, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found
4、in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are respons
5、ible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the
6、 UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 14, an inside back cover and a back cover. The BSI
7、 copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 13:22:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Reference number ISO 21550:2004(E) OSI 4002 I
8、NTERNATIONAL STANDARD ISO 21550 First edition 2004-10-01 Photography Electronic scanners for photographic images Dynamic range measurements Photographie Scanners lectroniques pour images photographiques Mesurages dintervalles dynamiques BS ISO 21550:2004 Licensed Copy: sheffieldun sheffieldun, na, S
9、un Nov 26 13:22:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI IS:05512 O4002(E) DPlcsid Fremia ihTs PDF file may ctnoian emdebt dedyfepcaes. In ccaocnadrw eith Aebods licensilop gnic,y this file mairp eb ynted iv roweb detu slahl ton ide ebtlnu deess the typefaces whice era hml era deddebicsnede to
10、i dnanstlaled t noeh computfrep reormign tide ehtin.g In wodlnidaot gnhis file, trapise atpecc tiereht nser ehnopsiiblity fo not infriigngn Aebods licensilop gnic.y ehT ISO tneClar Secrteiraat caceptl on siibality in this .aera Ai ebods a tredamafo kr Aebod SystemI sncotaropr.de teDails fo teh softw
11、acudorp erts sut deo crtaee this PDF file cna f ebi dnuon tlareneG eh Info leratit evo the file; tP ehDc-Frtaeion marapterew setpo erimizde for irpnti.gn Evyre caer neeb sah taken to sneeru that the file is suitlbae fosu re yb ISO memdob rebeis. In tlnu ehikletneve y ttah lborp aem leratit gno it is
12、 f,dnuo plsaee inform ttneC ehlar Secrteiraat ta the serddaig sleb nevwo. ISO 4002 All irthgs erse.devr lnUeto sswrehise specified, on trap fo this lbupictaion maeb y cudorperro de tuilizi den yna form ro na ybm ynae,s lecetrinoc ro mecinahcal, inclidung tohpcoiypodna gn micrfoilm, wittuoh repmissii
13、 non writign from ietI rehSa Ot tsserdda eh ebolw or ISOs memreb i ydobn the cnuotrfo y ttseuqer ehe.r ISO cirypothg fofice saCe tsopale 65 eneG 1121-HC 02 av leT. 4 + 10 947 22 1 11 xaF0 947 22 14 + 9 74 E-mail coirypthgiso.o gr We bwww.is.o gro Pulbisdehi n Switlrez dna ii ISO 4002 Allr ithgsr ese
14、devr BS ISO 21550:2004 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 13:22:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI IS:05512 O4002(E) I SO 4002 All irthgs ersedevr iii Contents Page Forewordiv Introduction v 1 Scope1 2 Normative references .1 3 Terms and definitions.1 4 Test chart.4 4.
15、1 Representation and recommended size.4 4.2 The reflective test chart5 4.3 The transparent test chart6 5 Test conditions6 5.1 General.6 5.2 Temperature and relative humidity .6 5.3 Luminance and colour measurements .7 5.4 Scanner settings .7 6 Measuring the Scanner OECF .7 6.1 General.7 6.2 Scanner
16、settings .7 7 Calculation of the scanner dynamic range.8 7.1 Luminance OECF 8 7.2 Scanner dynamic range8 7.3 Determination of the signal to noise ratio8 8 Presentation of results.9 8.1 General.9 8.2 Scanner OECF.10 8.3 Scanner dynamic range measurements.11 Annex A (normative) Scanner OECF Test Patch
17、es.12 Annex B (normative) Density shift to measure ISO scanner dmax.13 Bibliography .14 BS ISO 21550:2004 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 13:22:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI IS:05512 O4002(E) iv I SO 4002 All irthgs ersedevr Foreword ISO (the International Orga
18、nization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been establis
19、hed has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization
20、. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. P
21、ublication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such pate
22、nt rights. ISO 21550 was prepared by Technical Committee ISO/TC 42, Photography. BS ISO 21550:2004 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 13:22:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI IS:05512 O4002(E) I SO 4002 All irthgs ersedevr v Introduction The use of scanners to provide
23、digital image files is rapidly growing. A standard is needed in order to measure the ability of scanners to capture tones especially in the dark areas of the original. At the present time most manufacturers calculate the dynamic range from the bit depth of the implemented A/D conversion which is usu
24、ally higher than the actual capabilities of the scanner. This International Standard can be used for photofinishing, professional, graphic arts and consumer scanners. This International Standard specifies methods for measuring the ability of scanners to capture tones especially in the dark areas of
25、the original. The scanner measurements described in this International Standard are performed in the digital domain, using digital analysis techniques. A test chart of appropriate size and characteristics is scanned and the resulting data is analysed. The test chart described in this International S
26、tandard is designed specifically to evaluate continuous tone film and reflection scanners. It is not designed for evaluating electronic still-picture cameras, video cameras, or bi-tonal document scanners. BS ISO 21550:2004 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 13:22:36 GMT+00:00 200
27、6, Uncontrolled Copy, (c) BSI blank 4002:05512 OSI SB Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 13:22:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI INTENRATIONAL TSANDADR IS:05512 O4002(E) I SO 4002 All irthgs ersedevr 1 Photography Electronic scanners for photographic images Dynamic ra
28、nge measurements 1 Scope This International Standard specifies methods for measuring and reporting the dynamic range of electronic scanners for continuous tone photographic media. It applies to scanners for reflective and to scanners for transmissive media. 2 Normative references The following refer
29、enced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 5-2, Photography Density measurements Part 2: Geometric conditio
30、ns for transmission density ISO 5-4, Photography Density measurements Part 4: Geometric conditions for reflection density ISO 554, Standard atmospheres for conditioning and/or testing Specifications ISO 12231, Photography Electronic still-picture cameras Terminology ISO 12232:1998, Photography Elect
31、ronic still-picture cameras Determination of ISO speed ISO 14524, Photography Electronic still-picture cameras Methods for measuring opto-electronic conversion functions (OECFs) 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 12231 and the following
32、apply. 3.1 addressable photoelements number of active photoelements in an image sensor NOTE This is equal to the number of active lines of photoelements, multiplied by the number of active photoelements per line. 3.2 aliasing output image artefacts that occur in a sampled imaging system for input im
33、ages having significant energy at frequencies higher than the Nyquist frequency of the system 3.3 digital output level numerical value assigned to a particular output level, also known as the digital code value BS ISO 21550:2004 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 13:22:36 GMT+00:
34、00 2006, Uncontrolled Copy, (c) BSI IS:05512 O4002(E) 2 I SO 4002 All irthgs ersedevr 3.4 edge spread function ESF normalized spatial signal distribution in the linearized output of an imaging system resulting from imaging a theoretical infinitely sharp edge 3.5 effectively spectrally neutral charac
35、teristic of an imaging system whereby the output is the same as that produced from a spectrally neutral object 3.6 electronic scanners for photographic film scanner that incorporates an image sensor whose output is a digital signal that represents a still film image 3.7 fast scan direction scan dire
36、ction corresponding to the direction of the alignment of the addressable photoelements in a linear array image sensor 3.8 gamma correction process that alters the image data in order to modify the tone reproduction 3.9 image sensor electronic device that converts incident electromagnetic radiation i
37、nto an electronic signal; e.g. a charge coupled device (CCD) array 3.10 incremental gain function change in output level (digital code value) divided by the change in input level (luminance or exposure) as a function of input level NOTE 1 For the determination of incremental gain values, log input v
38、alues are not used. NOTE 2 If the input exposure points are very finely spaced and the output noise is small compared to the quantization interval, the incremental gain function may have a jagged shape. Such behaviour is an artefact of the quantization process and should be removed by using an appro
39、priate smoothing algorithm, or by fitting a smooth curve to the data. In some cases it may be desirable to fit a curve to the input-output data and then determine the incremental gain function by taking the first derivative of the function used for the curve fit. 3.11 incremental output signal input
40、 level multiplied by the system incremental gain at that level 3.12 incremental signal to noise ratio ratio of the incremental output signal to the root-mean-squared (rms) noise level, at a particular signal level NOTE This is typically expressed as a graph or table showing the rms noise level versu
41、s output signal level for the full range of output signal levels. 3.13 ISO scanner dynamic range difference of the maximum density where the incremental gain is higher than 0,5, as determined according to ISO 21550 to the minimum density that appears unclipped BS ISO 21550:2004 Licensed Copy: sheffi
42、eldun sheffieldun, na, Sun Nov 26 13:22:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI IS:05512 O4002(E) I SO 4002 All irthgs ersedevr 3 3.14 noise unwanted variations in the response of an imaging system 3.15 resolution measure of the ability of a digital image capture system, or a component of a di
43、gital image capture system, to capture fine spatial detail NOTE Resolution measurement metrics include resolving power, limiting visual resolution, SFR, Modulation Transfer Function (MTF) and Contrast Transfer Function (CTF). 3.16 sampled imaging system imaging system or device which generates an im
44、age signal by sampling an image at an array of discrete points, or along a set of discrete lines, rather than a continuum of points NOTE The sampling at each point is done using a finite size sampling aperture or area. 3.17 sample spacing physical distance between sampling points or sampling lines N
45、OTE 1 The sample spacing may be different in the two orthogonal sampling directions. NOTE 2 Measured in units of distance (e.g. microns, mm). 3.18 sampling frequency reciprocal of sample spacing NOTE This is expressed in samples per unit distance e.g. dots per inch (dpi). 3.19 scanner electronic dev
46、ice that converts a fixed image, such as a film or film transparency, into an electronic signal 3.20 scanner opto-electronic conversion function Scanner OECF relationship between the input density and the digital output levels for a scanner 3.21 slow scan direction direction in which the scanner mov
47、es the photoelements (perpendicular to the lines of active photoelements in a linear array image sensor) 3.22 spatial frequency response SFR measured amplitude response of an imaging system as a function of relative input spatial frequency NOTE The SFR is normally represented by a curve of the outpu
48、t response to an input sinusoidal spatial luminance distribution of unit amplitude, over a range of spatial frequencies. The SFR is normalized to yield a value of 1,0 at a spatial frequency of 0. 3.23 spectrally neutral test chart equality of the relative spectral power distributions of the incident
49、 and reflected (or transmitted) light BS ISO 21550:2004 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 13:22:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI IS:05512 O4002(E) 4 I SO 4002 All irthgs ersedevr 3.24 test chart arrangement of test patterns designed to test particular characteristics 3.25 test pattern specified arrangement of spectral reflectance or transmittance characteristics used in measuring an image quality attri