1、BS ISO10505:2009ICS 37.040.20NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDPhotography Root mean squaregranularity ofphotographicfilms Method ofmeasurementThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 30
2、June2009. BSI 2009ISBN 978 0 580 62022 5Amendments/corrigenda issued since publicationDate CommentsBS ISO 10505:2009National forewordThis British Standard is the UK implementation of ISO 10505:2009.The UK participation in its preparation was entrusted to TechnicalCommittee CPW/42, Photography.A list
3、 of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obl
4、igations.BS ISO 10505:2009Reference numberISO 10505:2009(E)ISO 2009INTERNATIONAL STANDARD ISO10505First edition2009-05-15Photography Root mean square granularity of photographic films Method of measurement Photographie Moyenne quadratique granulaire de films photographiques Mthode de mesure BS ISO 1
5、0505:2009ISO 10505:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing.
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9、 ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 All rights reservedBS ISO 10505:2009ISO 1050
10、5:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1 4 Measurement instrument . 3 4.1 General. 3 4.2 Microdensitometer 3 4.3 Spectral products . 6 4.4 Spatial frequency response. 7 4.5 Scanning motion. 7
11、5 Instrument electronics . 8 5.1 Conversion to density 8 5.2 Temporal frequency response of the instrument 8 5.3 Instrument noise . 8 6 Diffuse rms-granularity 8 6.1 Optical geometry. 8 6.2 Diffuse conversion factor g 9 7 Preparation of specimens 9 7.1 Sampling and storage 9 7.2 Exposure 10 7.3 Proc
12、essing. 10 7.4 Specimen uniformity 10 7.5 Sampled area. 10 8 Operation of the measurement instrument 10 8.1 Positioning the specimen 10 8.2 Specimen scanning 10 8.3 Control of focus 10 8.4 Rate of scan. 11 8.5 Density mode 11 9 Method of test . 11 9.1 Principle. 11 9.2 Statistical background . 11 9.
13、3 Construction of the median estimator and the 95 % confidence intervals. 12 9.4 Instrument noise . 13 9.5 Diffuse rms-granularity 14 9.6 Uncertainty of the rms-granularity result. 14 9.7 Reporting results 14 9.8 Summary of rms-granularity characterization parameters 15 Annex A (informative) Typical
14、 viewing magnifications for critical naked-eye viewing 16 Annex B (informative) Limiting the temporal frequency response of the measuring instrument . 18 Annex C (informative) The effects of specimen non-uniformity 20 Annex D (informative) Derived constants c for subgroup sizes 10, 20, , 200 . 21 An
15、nex E (informative) Determination of sample size for specified precision and subgroup size. 22 Bibliography . 24 BS ISO 10505:2009ISO 10505:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
16、(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 established has the right to be represented on that committee. International organizations, g
17、overnmental 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. International Standards are drafted in accordance with the rules given in the ISO/I
18、EC 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. Publication as an International Standard requires approval by at least 75 % of the mem
19、ber 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 patent rights. ISO 10505 was prepared by Technical Committee ISO/TC 42, Photography. BS I
20、SO 10505:2009ISO 10505:2009(E) ISO 2009 All rights reserved vIntroduction This International Standard specifies procedures for measuring and computing the root mean square granularity (rms-granularity) of photographic films. Its purpose is to provide guidance in making accurate measurements, and als
21、o to provide an objective basis for comparing films. This International Standard describes a method for making accurate rms-granularity measurements in the presence of instrument noise and minor sample imperfections. In principle, the measurement of rms-granularity is straightforward, but its determ
22、ination with accuracy is not a trivial matter. Experience has shown that the preparation of an imperfection-free sample is virtually impossible in usual practice. Therefore, considerable attention has been devoted to the definition of a method of accurately estimating the rms-granularity of a film i
23、n the presence of density fluctuations not caused by the intrinsic grain structure of the film. Research in rms-granularity (see Reference 10) has pointed out that the inclusion of several “artefact-induced” data values in a set of several thousand “grain-produced” data values may result in large er
24、rors in the rms-granularity estimate. Under these circumstances, the traditional method for estimating rms-granularity produces higher rms-granularity estimates than the new method. It can also be shown that this method produces results that are identical to those produced by the traditional method
25、when using artefact-free data. In either case, it is important to bear in mind that rms-granularity is a statistical estimate which is necessarily reported with its associated confidence intervals. In addition, the measurement process recognizes and accounts for the presence of instrument noise that
26、 can affect the accuracy of the rms-granularity estimate. BS ISO 10505:2009BS ISO 10505:2009INTERNATIONAL STANDARD ISO 10505:2009(E) ISO 2009 All rights reserved 1Photography Root mean square granularity of photographic films Method of measurement 1 Scope This International Standard describes a meth
27、od for determining the intrinsic root mean square granularity (rms-granularity) of photographic films. Intrinsic rms-granularity refers to those density fluctuations produced solely by the distribution of developed image forming centres in the photographic emulsion. Continuous-tone monochrome (silve
28、r absorbing species) and colour (dye absorbing species) materials coated on a transmitting support can be measured by the procedures described in this International Standard. This International Standard is intended for imaging systems with viewing magnifications between 5 and 12 (see Annex A). The f
29、ollowing kinds of granularity measurements are not covered by this International Standard, even though they are photographically important: reflecting materials (photographic papers); materials having emulsion coated on both sides of the support (e.g. some X-ray films); the estimation of the noise p
30、ower spectrum (Wiener spectrum). 2 Normative references The following referenced 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) ap
31、plies. ISO 5-2, Photography Density measurements Part 2: Geometric conditions for transmission density ISO 5-3, Photography Density measurements Part 3: Spectral conditions 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 transmittance factor
32、T ratio of the measured flux transmitted by a specimen to the measured flux when the specimen is removed from the sampling aperture of the measuring device NOTE TJT= where Tis the transmitted flux; Jis the aperture flux. BS ISO 10505:2009ISO 10505:2009(E) 2 ISO 2009 All rights reserved3.2 transmissi
33、on density DTlogarithm to the base 10 of the reciprocal of the transmittance factor, T NOTE 10log 1/TD T= . 3.3 microtransmittance factor transmittance factor of a small area of a film or plate, measured using a suitable instrument such as a microphotometer NOTE In general, the microtransmittance fa
34、ctor of a uniformly exposed and developed film sample varies from point-to-point on the surface. The measured microtransmittance factor of a given film or plate can depend on the optical geometry of the instrument in which it is measured. 3.4 microdensity D transform of the microtransmittance factor
35、 in accordance with the usual relation 10log 1/D T= 3.5 graininess sensation produced, in the mind of an observer viewing a photographic image, by random inhomogeneity in what should be structureless areas NOTE Graininess is a subjective quantity that is necessarily measured by psychophysical method
36、s and, as such, is outside the scope of this International Standard. 3.6 root mean square granularity rms-granularity Dobjective characterization of the spatial microdensity fluctuation of a uniformly exposed and developed photographic layer, determined in accordance with this International Standard
37、 NOTE 1 See Reference 3. NOTE 2 In contrast to graininess, rms-granularity is an objective quantity. NOTE 3 The spatial fluctuation is observed when the microdensity of the layer is measured at various points over the surface and is the result of the random distribution of the absorbent species in t
38、he layer. The fluctuation in the microdensity over an area of a specimen is characterized by its standard deviation, D, and is generally a function of the specimens macrodensity. This quantity is termed the “rms-granularity” and in all conceivable cases of interest, this population parameter cannot
39、be determined exactly because of finite sample size. The method for estimating Dis described in Clause 9. NOTE 4 The relation between graininess and rms-granularity is as follows: rms-granularity is intended to be an objective correlate of graininess. The methods of measuring film rms-granularity as
40、 defined in 3.6 have been found to give values that generally correlate with the magnitude of the graininess sensation produced when images produced by the film are viewed under suitable conditions. The just-noticeable differences in graininess, detectable by observers viewing areas having a visual
41、density of about 1,0, correspond to differences in rms-granularity of 6 % for a uniform field, of 16 % for an average scene and of 30 % for a complex or busy scene4. Because rms-granularity does not account for effects encountered in multiple stage imaging processes, methods for evaluating the grain
42、iness of final images have been developed11. These methods are particularly useful for comparing the image graininess of different final print formats when produced from different negative formats and film types. BS ISO 10505:2009ISO 10505:2009(E) ISO 2009 All rights reserved 33.7 specimen piece of
43、photographic film or photographic plate on which rms-granularity measurements are made NOTE The specimen can be specific or constitute a sample from a population whose rms-granularity is being determined. 3.8 diffuse conversion factor g factor used to convert small transmission (projection) density
44、differences produced by most microdensitometers to small diffuse density differences, as determined in accordance with 6.2 3.9 spatial frequency passband part of the spatial frequency spectrum that passes through the measuring system NOTE The spatial frequency passband is determined by the cut-off f
45、requencies of the system on the low side and the high side of the spatial frequency. The passband characteristics required for the measuring instrument are specified in 5.2. 4 Measurement instrument 4.1 General This clause describes the basic elements of an instrument suitable for the measurement of
46、 rms-granularity. The generic instrument described in this clause follows the general principles for a linear, incoherent microdensitometer used in an overfilled, image-scanning mode. Microdensitometers of different designs may be employed, provided they are shown to conform to the physical optics p
47、rinciples required for linearity and incoherent illumination, as described in References 6, 7, 8 and 9. 4.2 Microdensitometer 4.2.1 Apparatus A typical microdensitometer is shown schematically in Figure 1. Its key elements are as follows: light source (1): an incoherent source of suitable spectral p
48、ower distribution; illumination filter (2), which produces spectral transmittance necessary to conform to 4.2.2; condenser lens (3): optics that fill the influx aperture uniformly with light; influx aperture (4): in the optical system shown in Figure 1, this aperture limits the area of the specimen
49、that is illuminated in order to minimize stray light in the optical system; influx optics (5), which images the influx aperture (4) on the specimen at point 6; specimen (6): emulsion (7) facing the efflux optics; efflux optics (8), which collects the light transmitted by the specimen and focuses it upon the efflux aperture of the instrument; efflux (measuring) aperture (9): this aperture, projected back onto the specimen, determines the area of the specimen whose density is being mea
