1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 12231:2012Photography Electronic stillpicture imaging VocabularyBS ISO 12231:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 12
2、231:2012. Itsupersedes BS ISO 12231:2005 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee CPW/42, Photography.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include al
3、l the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2012. Published by BSI StandardsLimited 2012ISBN 978 0 580 68172 1ICS 01.040.37; 37.040.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This
4、British Standard was published under the authority of theStandards Policy and Strategy Committee on 29 February 2012.Amendments issued since publicationDate Text affectedBS ISO 12231:2012 ISO 2012Photography Electronic still picture imaging VocabularyPhotographie Prises de vue lectroniques Vocabulai
5、reINTERNATIONAL STANDARDISO12231Third edition2012-02-01Reference numberISO 12231:2012(E)BS ISO 12231:2012ISO 12231:2012(E)ii ISO 2012 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2012All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in
6、any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749
7、09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 12231:2012ISO 12231:2012(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally
8、carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the wo
9、rk. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.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 Intern
10、ational Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication 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
11、elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 12231 was prepared by Technical Committee ISO/TC 42, Photography.This third edition cancels and replaces the second edition (ISO 12231:2005), which has b
12、een technically revised. ISO 2012 All rights reserved iiiBS ISO 12231:2012ISO 12231:2012(E)IntroductionElectronic still picture imaging concepts are drawn from traditional photography, electronics, video, and information technology. In some cases the concepts are redefined to apply to electronic sti
13、ll picture imaging. For example, unlike traditional photography, measurements cannot be defined in terms of “film” or “sensitized material”, since images acquired by digital image capture devices are stored electronically and are not immediately exposed on film. The meaning of shutter and exposure t
14、ime is also different for digital image capture devices, because an electronic imaging sensor typically has image acquisition characteristics that are different from those of film.This International Standard provides a vocabulary which standardizes the use and meaning of terms associated with electr
15、onic still picture imaging. It is organized alphabetically and follows natural (English) word order wherever possible. The source documents for most of the definitions provided in this International Standard are International Standards on electronic still picture imaging developed by ISO/TC 42 and I
16、SO/TC 130.Where possible, users are advised to verify if a more recent edition of the source document has been published, which contains an updated version of the term and definition. Future revisions of this International Standard will include updated terms and definitions consistent with the sourc
17、e documents at the time the revision is prepared.iv ISO 2012 All rights reservedBS ISO 12231:2012Photography Electronic still picture imaging Vocabulary1 ScopeThis International Standard defines terms used in electronic still picture imaging.Only terms related to electronic still picture imaging are
18、 defined. These terms are relevant to current tasks or are of general interest in electronic still picture imaging.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated refere
19、nces, the latest edition of the referenced document (including any amendments) applies.ISO/IEC 10918-1, Information technology Digital compression and coding of continuous-tone still images: Requirements and guidelinesISO 12232, Photography Digital still cameras Determination of exposure index, ISO
20、speed ratings, standard output sensitivity, and recommended exposure indexISO 12234-2, Electronic still-picture imaging Removable memory Part 2: TIFF/EP image data formatISO 15739, Photography Electronic still-picture imaging Noise measurementsISO 21550, Photography Electronic scanners for photograp
21、hic images Dynamic range measurementsIEC 61966-2-1, Multimedia systems and equipment Colour measurement and management Part 2-1: Colour management Default RGB colour space sRGB3 Terms and definitions3.1absolute colorimetric coordinatestristimulus values, or other colorimetric coordinates derived fro
22、m tristimulus values, where the numerical values correspond to the magnitude of the physical stimulusEXAMPLE When CIE 1931 standard colour-matching functions are used, the Y-coordinate value corresponds to the luminance, not the luminance factor (or some scaled value thereof).ISO 22028-1:2004, defin
23、ition 3.13.2adapted whitecolour stimulus that an observer who is adapted to the viewing environment would judge to be perfectly achromatic and to have a luminance factor of unity; i.e. absolute colorimetric coordinates that an observer would consider to be a perfect white diffuserNOTE 1 The adapted
24、white can vary within a scene.NOTE 2 See also adopted white (3.5).NOTE 3 This term is also defined in ISO 22028-1 and ISO/TS 22028-3.ISO/TS 22028-2:2006, definition 3.1INTERNATIONAL STANDARD ISO 12231:2012(E) ISO 2012 All rights reserved 1BS ISO 12231:2012ISO 12231:2012(E)3.3additive RGB colour spac
25、ecolorimetric colour space having three colour primaries (generally red, green and blue) such that CIE XYZ tristimulus values can be determined from the RGB colour space values by forming a weighted combination of the CIE XYZ tristimulus values for the individual colour primaries, where the weights
26、are proportional to the radiometrically linear colour space values for the corresponding colour primariesNOTE 1 A simple linear 3x3 matrix transformation can be used to transform between CIE XYZ tristimulus values and the radiometrically linear colour space values for an additive RGB colour space.NO
27、TE 2 Additive RGB colour spaces are defined by specifying the CIE chromaticity values for a set of additive RGB primaries and a colour space white point, together with a colour component transfer function.NOTE 3 This term is also defined in ISO 22028-1 and ISO/TS 22028-3.ISO/TS 22028-2:2006, definit
28、ion 3.23.4addressable photoelementsnumber of active photoelements in an image, which is equal to the number of active lines of photoelements multiplied by the number of active photoelements per lineNOTE 1 It is possible that the number of addressable photoelements may be different for the different
29、colour records of an image. When the signal values of the photoelements are digitized, the digitized code values may be referred to as picture elements, or pixels.NOTE 2 This term is also defined in ISO 16067-1, ISO 16067-2 and ISO 21550.ISO 12233:2000, definition 3.13.5adopted whitespectral radianc
30、e distribution as seen by an image capture or measurement device and converted to colour signals that are considered to be perfectly achromatic and to have an observer adaptive luminance factor of unity, i.e. colour signals that are considered to correspond to a perfect white diffuserNOTE 1 The adop
31、ted white can vary within a scene.NOTE 2 No assumptions can be made concerning the relation between the adapted or adopted white and measurements of near perfectly reflecting diffusers in a scene, because measurements of such diffusers will depend on the illumination and viewing geometry, and other
32、elements in the scene that can affect perception. It is easy to arrange conditions for which a near perfectly reflecting diffuser will appear to be grey or coloured.NOTE 3 See also adapted white (3.2).NOTE 4 This term is also defined in ISO 17321-1 and ISO 22028-1.3.6albumend-user created object use
33、d to logically group data objects according to some user-defined criteriaNOTE An album might or might not be a physical folder in a file system. In this International Standard, an album is a type of association.ISO 15740:2008, definition 3.13.7aliasingoutput image artefacts that occur in a sampled i
34、maging system for input images having significant energy at frequencies higher than the Nyquist frequency of the systemNOTE 1 These artefacts usually manifest themselves as moir patterns in repetitive image features or as jagged “stairstepping” at edge transitions.2 ISO 2012 All rights reservedBS IS
35、O 12231:2012ISO 12231:2012(E)NOTE 2 This term is also defined in ISO 12233, ISO 16067-2 and ISO 21550.ISO 16067-1:2003, definition 3.23.8aliasing ratiovalue equal to the “maximum minus minimum” modulation divided by the “average” modulation of an electronic still picture camera when imaging a freque
36、ncy burst of constant spatial frequencyNOTE The aliasing ratio is described in 6.4 of ISO 12233:2000.ISO 12233:2000, definition 3.43.9applicationimage application software for use on a personal computerISO 12231:2005, definition 3.53.10Application Programming InterfaceAPIhigh-level functional descri
37、ption of a software interfaceNOTE 1 An API is typically language-dependent.NOTE 2 This was taken from ISO 15740:2005, definition 3.2, which has been cancelled and replaced by ISO 15740:2008.3.11artefactual attributeattribute of image quality that, when evident in an image, nearly always leads to a l
38、oss of overall image qualityNOTE The commonly used terms defect and impairment are similar in meaning.EXAMPLE Examples of artefactual attributes include noise and aliasing.ISO 20462-1:2005, definition 3.1, ISO 20462-3:2005, definition 3.13.12 aspect ratio3.12.1image aspect ratioratio of the image wi
39、dth to the image heightISO 12233:2000, definition 3.10, ISO 15740:2008, definition 3.163.12.2pixel aspect ratioratio of the distance between sampling points in the two orthogonal sampling directionsNOTE 1 If the distances are equal, the pixel aspect ratio equals 1:1, and is said to be “square”.NOTE
40、2 See also image aspect ratio (3.12.1).ISO 12231:2005, definition 2.6.23.13associationlogical construct used to expose a relationship between discrete objectsNOTE Associations are used to indicate that separate data objects are related. Associations are represented like folders, and may be nested us
41、ing a standard branched hierarchical tree structure.EXAMPLE A time sequence or user-defined groupings by content or capture session.ISO 15740:2008, definition 3.2 ISO 2012 All rights reserved 3BS ISO 12231:2012ISO 12231:2012(E)3.14attributeaspect, dimension, or component of overall image qualityNOTE
42、 1 See also artefactual attribute (3.11) and preferential attribute (3.138).NOTE 2 This term is also defined in ISO 20462-1 and ISO 20462-3.EXAMPLE Examples of image quality attributes include image structure properties such as sharpness and noise; colour and tone reproduction properties such as con
43、trast, colour balance, and relative colourfulness; and digital artefacts such as aliasing, contouring, and compression defects.3.15attribute just noticeable differenceattribute JNDmeasure of the detectability of appearance variations, corresponding to a stimulus difference that would lead to a 75:25
44、 proportion of responses in a paired comparison task in which univariate stimuli pairs were assessed in terms of a single attribute identified in the instructionsNOTE 1 As an example, a paired comparison identifying the sharper of two stimuli that differed only in their generating system modulation
45、transfer function (MTF) would yield results in terms of sharpness attribute JNDs. If the MTF curves differed monotonically and did not cross, the outcome of the paired comparison would depend primarily upon the observers ability to detect changes in the appearance of the stimuli as a function of MTF
46、 variations, with little or no value judgement required of the observers. NOTE 2 If observers are instead asked to choose which of a pair of stimuli is higher in overall image quality, and if the stimuli in aggregate are multivariate, such that the observer must make value judgements of the importan
47、ce of a number of attributes, rather than focusing on one aspect of image appearance, it is observed experimentally that larger objective stimulus differences (for example, MTF changes) are required to obtain a 75:25 proportion of responses, which in this case corresponds to a quality JND.NOTE 3 A J
48、ND is a statistical quantity, derived from a number of observations. An observer assessing a single pair of images differing by one attribute JND is unlikely to be confident that he or she has detected the sample difference. A stimulus difference of approximately three JNDs is usually needed for an
49、observer of average sensitivity to feel reasonably certain of his or her assessment.NOTE 4 See also quality JND (3.143).NOTE 5 Adapted from ISO 20462-1.3.16categorical sort methodpsychophysical method involving the classification of a stimulus into one of several ordered categories, at least some of which are identified by adjectives or phrases that describe different levels of image quality or attributes thereofNOTE The application of adjectival descriptors is strongly affected by the range of st
