1、BRITISH STANDARD Multime dia systems and equipment Colour measurement and management Part 8: Multimedia colour scanners The European Standard EN 61966-8:2001 has the status ofa British Standard ICs 33.160.60; 35.180 BS EN IEC 6 1 966-8 1200 1 6 1 966-8 1200 1 Wk present to the responsible European c
2、ommittee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. - A list of organizations represented on this committee can be obtained on request to its secretary. From
3、1 January 1997, all IEC publications have the number 60000 added to the old number. For instance, IEC 27-1 has been renumbered as IEC 60027-1. For a period oftime during the change over from one numbering system to the other, publications may contain identifiers from both systems. Cr oss-r e fer enc
4、 e s The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalo
5、gue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document compr
6、ises a front cover, an inside front cover, the EN title page, pages 2 to 38, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. O BSI 03 December 2001 ISBN O 580 38732 I EUROPEAN STANDARD EN 61966-8 NORME EUROPENNE EU
7、ROPflSCHE NORM May 2001 ICs 33.160.60; 35.180 English version Multimedia systems and equipment - Colour measurement and management Part 8: Multimedia colour scanners (IEC 61 966-812001) Systmes et appareils multimdia - Mesure et gestion de la couleur Partie 8: Numhiseurs couleur (CE1 61966-812001) M
8、ultimediasysteme und -ger%k - Farbmessung und Farbmanagement Te I 8: Mu It med ia-Farbscan ner (IEC 61966-812001) This European Standard was approved by CENELEC on 2001-04-01. CENELEC members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this
9、European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions
10、(English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of Aust
11、ria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique
12、Eurqfhlsches Komitee f, r Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels O 2001 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61966-8:2001 E Page 2 EN 61966-8:2001 Foreword The text of docum
13、ent 100/192/FDIS, future edition 1 of IEC 61966-8, prepared by IEC TC 100, Audio, video and multimedia systems and equipment, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61966-8 on 2001-04-01. The following dates were fixed: latest date by which the EN has to be
14、implemented at national level by publication of an identical national standard or by endorsement latest date by which the national standards conflicting with the EN have to be withdrawn (don) 2002-01-01 (dow) 2004-04-01 Annexes designated “normative“ are part of the body of the standard. Annexes des
15、ignated “informative“ are given for information only. In this standard, annexes A, B and ZA are normative and annex C is informative. Annex ZA has been added by CENELEC. Endorsement notice The text of the International Standard IEC 61966-8:2001 was approved by CENELEC as a European Standard without
16、any modification. O BSI 03 December Page 3 EN 61966-8:2001 CONTENTS Page INTRODUCTION . . 6 1 Scope and object 2 Normative references . 9 3 Terms and definitions . IO 4 Letters and symbols I1 5 Conditions 11 5.1 General CO 5.2 Output digital image data . 6 Measurement equipment and target of scan 12
17、 6.1 Spectrophotometer 12 6.2 Spectroradiometer . 12 6.3 Specification of the target 13 7 Spectral power distrib 15 7.1 Characteristics to be measured . 15 7.2 Measurement conditions 15 7.3 Presentation of results . 15 8 Tone characteristics 17 8.1 Characteristics to be measured 17 8.2 Measurement c
18、onditions 17 8.3 Method of measurement 17 8.4 Calculation of results . 17 8.5 Presentation of results 18 19 9 Inverse tone characteristics 9.1 Characteristics to be calculated 19 9.2 Method of calculation. . I9 9.3 Presentation of results 20 10 Spectral responsivity charac .20 10.1 Characteristics t
19、o be measured . . 20 10.2 Measurement conditions 21 10.3 Method of measurement 21 10.4 Presentation of results . 21 11 Spatial non-uniformity 25 11 .I Characteristics to be measured 25 11.2 Measurement conditions . .25 11.3 Method of measurement 25 11.4 Presentation of results . 27 12 Mid-term insta
20、bility 28 12.1 Characteristics to be measured . 28 12.2 Measurement conditions . .28 12.3 Method of measurement 29 12.4 Presentation of results . 29 O BSI 03 December Page 4 EN 61966-8:2001 13 Large area spatial crosstalk 29 13.1 13.2 13.3 13.4 Annex A A . 1 A.2 A . 3 A.4 A . 5 Annex B Character ist
21、 ics to be m eas u red . 29 M eas u rem e nt co nd it ions 29 Method of measurement 30 Presentation of results . 31 normative) Estimation of multiband of wavelength sensitivities 32 Quantities to be estimated 32 Input to the algorithm . 32 Internal variables of the algorithm 33 Estimation algorithm
22、33 normative) Scanner model output data from estimated multiband Output to the algorithm 33 sensitivities . 35 Annex C (informative) Examples for the application of the spectral characteristics . 36 C.l Calculation of the ICC profiles 36 C.2 36 corresponding European publications . 38 Calculation of
23、 an optimized conversion for sRGB colour space Annex ZA (normative) Normative references to international publications with their Bibliography 37 Figure 1 . Specification of the target for characterization of multimedia colour scanners . 13 Figure 2 . Example of graphical representation of multiband
24、 spectral reflection of a colour patch 14 Figure 3 . Scanning area and the points of measurement . 15 Figure 4 . Example of the normalized spectral power distribution of the built-in light source . 16 Figure 5 . Example of reporting form of tone characteristics, light flux vs . output data 19 Figure
25、 6 . An example of multiband spectral responsivity, SR, SG and SB 24 Figure 7 . Example of reporting form of the overall multiband spectral responsitivity, Sns, . Sns, and Sns, 25 Figure 8 . Measurement points for spatial non-uniformity 26 Figure 9 . Example of report of mid-term instability . 29 Fi
26、gure 10 . Target for the measurement of spatial crosstalk . 30 Table 1 . Example of reporting form of a spectral table . 14 Table 2 . Example of multiband spectral characteristics of the light source . 16 Table 3 . Example of reporting form of the polynomial coefficients of the red, green and blue c
27、hannel . 18 Table 4 . Example of reporting form of the polynomial coefficients of the red, green and blue channels 20 22 Table 6 . Reporting form for the measurement of spatial non-uniformity . 28 Table 7 . Reporting form for the measurement of spatial crosstalk 31 Table 5 . Example of reporting for
28、m of the multiband responsitivity characteristics O BSI 03 December Page 5 EN 61966-8:2001 Table 8 - Reporting form of average data and maximum crosstalk given by relative maximum differences and relative standard deviations of data in red, green and blue channels (8 bits per channel) 31 O BSI 03 De
29、cember Page 6 EN 61966-8:2001 INTRODUCTION This introduction is intended to distinguish the field of application of IS0 12641 and IEC 61966-8. In order to standardize the calibration procedure for input scanners used in the printing and Prepress industry, IS0 12641 was published in 1997. This part o
30、f IEC 61966 targets colour scanners for multimedia applications by providing characterization data necessary for colour management in open multimedia systems. It characterizes any multimedia colour scanners for consumer use, typically being connected to personal computers so as to capture colour ima
31、ges and display the colour information, either locally or distributed worldwide. In such applications, colour management is important. Any red - green - blue data should have their colorimetric attributes clearly specified. The characterization data reported from this part of IEC 61966 will be used
32、for the calculation of equipment specific colorimetric characterization so that colour management in open systems can be conducted. The capture of colour information in a Prepress input scanner usually assumes that the source is a positive film (transparent) original. The second most common type of
33、original is positive photographic printing paper (reflective). Recently, Prepress input scanners can support various types of reflective originals in addition to printing paper and can also capture an image directly from a negative film, although this is not yet very common. Due to these circumstanc
34、es, IS0 12641 was established for Prepress digital data exchange corresponding to transparent and reflective originals. However, a standard colour target for transparent film negative originals has not yet been established. Spectral sensitivity characteristics of Prepress scanners are not derived fr
35、om the calculation based on a special colour system or the spectral distribution of printing ink; but are base signals relatively close to the three primary colours (red, green, blue) acquired for calibration purposes. The characteristics of the Prepress input scanners are guaranteed by the experien
36、ce of the operator or the sophistication of the colour processing application so that subtle variations among the colours appear in the printed result. In fact, printing and Prepress scanners have many settings that are made available to professional users, and the operator can control the input sca
37、nner characteristics in a non-linear fashion to suit their objectives. In older input scanners, these controls were part of the stand-alone scanner system itself. For the scanners of the printing industry, these controls are typically part of the colour processing application software which processe
38、s the signals after capture and transfers them to the general purpose computer (workstation or server). In other words, a highly experienced and skilled operator can adjust the settings to freely change scanner characteristics such as tone and colour separation as he desires. Furthermore, scanner ch
39、aracteristics can be changed to correct and compensate for the characteristics of the original image target, such as colour fogging, as well as absorb them, and the operator can even change scanner colour separation conditions (typically cyan, yellow, magenta and black) in anticipation of the later
40、printing process so as to obtain the most feasible printed result. As such, on the site of the Prepress scanner, good colour separation (reproduction) is and has been dependent on the skill of the operator. All Prepress input scanners show variation in colour sensitivity characteristics depending on
41、 types, manufacturers, manufactured time and condition. Prepress input scanners tend to show less variation than other general-purpose multimedia colour scanners because of their usage in critical colour capturing in a closed system in comparison with the worldwide open system such as the Internet.
42、There has never been an attempt to standardize the colour character- istics of Prepress input scanners put on the market by different manufacturers. O BSI 03 December Page 7 EN 61966-8:2001 However, it is demanded that the printing process should produce essentially the same results from the same or
43、iginal regardless of the input scanner used. This demand has been accomplished by the skill of the operator. For this reason, the process of scanning, including colour processing for the raw data, should involve the human operator, and the total system be considered as one system. In this human-mach
44、ine interaction system, the characteristics can be understood as unified or standardized. Under these circumstances, and in consideration of the actual work process, ISO/TC 130 (Graphic technology) has established a method using a colour target as stipulated in IS0 12641 for Prepress input scanner c
45、alibration that includes functions capable of handling colour changes accompanying local distortions in colour regions. These targets for both positive reflective material (photographic printing paper) and positive transmission material (photographic film) are implemented by the photographic manufac
46、turers on their specific materials of their particular products. Multimedia colour scanners for general use which are much less expensive in comparison with Prepress input scanners, are available for small office/home office personal computers. Targets for scanning are not specified as in Prepress i
47、nput scanners. Images of natural objects such as the petals of violets, green plants or human skin will be most important. As many of the users of multimedia colour scanners are not colour experts, it is preferable to have an automatic system requiring minimal adjustment. The manufacturers of this t
48、ype of colour scanner do not provide colorimetric specifications of the red - green - blue data obtained from their scanner on one hand. On the other hand, the data obtained from the multimedia colour scanner are easily compressible and compatible to the World Wide Web and anonymous users will use t
49、he colour information in colour reproduction without having available the specific features of the original generator. Prepress scanners have been used for many years in the printing and Prepress industry and an environment has already been created in which only Prepress scanners meeting certain critical criteria are selected. This being the case, there is no need for a new evaluation of pre- press input scanner performance. In such an environment, however, the maintenance of input scanner quality is important and it is necessary and sufficient to calibrate a scann
