1、CENELEC EN*b1*bLO 96 3404583 0177182 299 BRITISH STANDARD Prints and transparencies produced from electronic sources - Assessment of image quality The European standard EN 61610 : 1996 has the status of a British Standard ICs 36.240.20 37.100 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY
2、COPYRIGHT LAM 3s EN i1610 : 1996 EC 1610 : 1995 CENELEC EN*bL*bLO 96 W 3404583 0177183 125 = Amd. No. BS EN 61610 : 1996 Date Text affected Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee EPUl, Audio, video and multimedia
3、 systems and equipment, to Subcommittee EPUlB, Equipment and systems in the field of audio, video and audiovisual engineering, upon which the foilowing bodies were represented: Association of British Theatre Technicians Audio Engineering Society British Broadcasting Corporation British Educational S
4、uppliers? Association British Radio and Electronic Equipment Manufacturers? Association British Telecommunications plc Federation of British Audio Federation of the Electronics Industry Independent Television Association (rrvA) Institute of Sound and Communication Engineers institution of Electrical
5、 Engineers International Association of Broadcasting Manufacturers Professional Lightmg and Sound Association Royal institute of British Architects Society of Cable Television Engineers This British Standard, having been prepared under the direction of the Electrotechnicai Sector Board, was publishe
6、d under the authority of the Standards Board and comes into effect on 16 August 1996 o BI 1996 The foilowing BSI references relate to the work on this standard: Committee reference EPUIW3 Draft for comment 93?205914 DC ISBN O 580 26120 4 I - CENELEC EN*bL*hLO b 3404583 0377384 Ob3 BS EN 61610 : 1996
7、 Contents page Committees responsible inside front cover ii Nationai foreword 2 Foreword 3 Text of EN 61610 i O BI 1996 - CENELEC EN*bL*bLO 96 = 3404583 OL77L85 TT8 BS EN 61610 : 1996 National foreword This British Standard has been prepared by Subcommittee EPL/100/3 and is the English language vers
8、ion of EN 61610 : 1996 Prints and transparencies producedfrom electrorzic soumes - Assessment of imge quality, published by the European Committee for Electrotechnical Standardization (CENELEC). It is identical with IEC 1610 : 1995, pubished by the International Electrotechnicd Commission (IEC). Cro
9、ss-references Publication referred to Corresponding British Standard BS 1384 Photographic density measurements Part 1 : 1985 Guide for terms, symbols and notations Part 2 : 1993 Spec(A) and ;(A) are the functions specified as the CIE 1931 standard colorimetric observer for a view angle of 2“ (see IS
10、O/ClE 10527). 4.3.3 Relation between input values and tristimulus values When the input signal is a standard analogue or digital video signal, the appropriate colorimetric specifcation should be used to transform corresponding tristimulus values. The conversions from R, G, B to the tristimulus value
11、s shall be made by the following equations according to the video standard used. CENELEC EN*bL*blO b 3404583 OL77L92 138 Page 7 EN 61610 : 1996 For standard NTSC system with standard illuminant C X = 0,60674 R + 0,17353 G + 0,20025 B Y = 0,29884 R + 0,58673 G + 0,11443 B Z= 0,00000 R + 0,0661 1 G +
12、1,11566 B For standard PAUSECAM systems with standard illuminant D, X= 0,43066 R + 0,34155 G + 0,17819 B Y = 0,22206 R + 0,70666 G + 0,07 128 B Z= 0,02019 R + 0,12956 G + 0,93848 B For any standard HDTV system The equations should be decided in accordance with the chromaticity coordinate values for
13、the input primary colours, and for the reference white, in accordance with the method described in 2. 5 Methods of measurements 5.1 Gamut of colours 5.1.1 Characteristics to be determined The maximum reproducible colour range m terms of the psychometric lightness and chromaticity. 5.1.2 Measurement
14、procedure a) The test signais containing input saturated colours shall be generated as specified by this standard.The signals shall correspond to the colours white, yellow, cyan, green, magenta, red, blue, and black as prints and transparencies. The level of each input signal shall be in accordance
15、with table 1. CENELEC EN*bL*b10 9b 3404583 0177193 079 H Page 8 EN 61610 : 1996 I imite 2 Yellow 3cym 4 Green 5 Magenta 6 Red 7 Blue 8 Black Table 1 - Input signal specification 1 O0 100 1 O0 1 O0 O 1 O0 O 100 100 O 1 O0 O O O O O Colours input signais % B 100 O 1 O0 O 100 O 100 O If the equipment a
16、ccepts standard video signals, the standard colour bar generator to produce colour bars (a) lKXl/O (see lTU-R Recommendation BT 471-1) may be used. b) The spectral density d(A), or spectral reflectance or spectral transmittance p(A), for object coiours of the prints or ihmhant colours of transparenc
17、ies, corresponding to the test signals, shall be measured for wavelengths from 400 nm to 700 nm in 10 nm steps. If spectral density is adopted for the measurement, it shall be converted to spectral reflectance or transmittance by the following formula: p(A) e) The tristimulus values, X, Y, 2 shall b
18、e calculated for each colour (see 4.3.2). 5.1.3 Presentation of results The measured spectral characteristics for the eight colours, including white and black, shall be plotted as the curves (see figure 1). The calculated tristimulus values shall be converted to values in the CIE 1976 colour space,
19、Lab as defined in CIE 15.2 for eight colours. They shall be reported as a table (see table 2), together with the kind of the standard iliuminant used for calculation. The results shall also be presented as graphs, as shown in figure 2. La - 116,O P-16,0 b - 200 ,O(Y-Z) CENELEC EN*hL*hLO b 3404583 01
20、77194 TOO Page 9 EN 61610 : 1996 where x X Xn xn x - (-) fm - L 0,008856 Yi Y Yn Yn Y - (-) fo* - L 0,008856 z Z zn 2, z - (-1 fop. - L 0,008856 and X 16,O X X - 7,787 - t - fa - s 0,008856 Xn 116,O Xn Y fo* - 5 0,008856 Y 16,O Y - 7,787 - + - Yn 116,O 4 Z 16,O Z 2, 116,O zn fa - s 0,008856 Z- 7,787
21、 - + - and where X, Y, 2, are the tristimulus values for the illuminant of the colorimetric system adopted for the input signal. For the NTSC system: X, = 0,98054 Z,= 1,18181 For the PAUSECAM system: X, = 0,95041 2, = 1,08825 Y, 1,00000 Y, 1,00000 For the systems other than the above, taking ,it0 ac
22、count the specific illuminant, S(A): S(A) ;(A) A JViS Y,. 1,00000 CENELEC EN*bL*bLO 96 3404583 OLL95 947 M Page 10 EN 61610 : 1996 O. 8 O. 6 P(N 0.4 0.2 n - 400 450 500 550 600 650 Wmelength (i) Figure 1 - Spectral characteristics of saturate colours Table 2 - Tabular report for gamut of colours whi
23、te Yellow cyan Green Magenta Red Blue Black Standard illuminant: 700 CENELEC EN*bL*bLO 96 3404583 0377396 883 Page 11 EN 61610 : 1996 100 50 b0 -50 -100 -100 -50 O 50 100 a+ Figure 2a - Gamut of colours expressed in (u*,b? plane M O0 R U - 100 -50 O 50 100 a* Figure 2b - Gamut of colours expressed i
24、n (u* Aa*= ; Ab= ; Al? D,(O,l) and D,(O,l) are the maximum and the minimum optical densities at spatial frequency s = O,i mm-, respectively. NOE -To avoid aliasing, the aperture width w should be given by ws (2fm)- wheref- is the highest spatial frequency to be measured as determined in step b). 5.7
25、.3 Presentation of results The measured results, v(s), for each spatial frequency shall be reported as curves exemplified in figure 7. The aperture size of the micro densitometer shall be reported in millimetres. CENELEC EN*bL*blO 96 3404583 O377206 552 Page 21 EN 61610 : 1996 I 1 1 O ,8 0.6 0.4 O 1
26、 1 10 NOTE - The spatial frequency range may be changed so as to cover the spatiai frequency for v(s) = 0,3. Figure 7 - Spatiai frequency response resolution 5.8 Image stabilio under exposure to light (light fstness) 5.8.1 Characteristics to be determined The image stability when the prints or trans
27、parencies are exposed to normal room lighting conditions. 5.8.2 Measurement procedure a) Produce a sample of print or transparency of the specified image. The specification of the he corresponding input signai is specified in table 6. image is shown in figure 8. NOTE -The numbers correspond to the c
28、olours in table 6. Figure 8 - Profile of printed image Page 22 EN 61610 : 1996 Colours 1 White 2 Yellow 4 Green 6 Red 7 Blue 8 Black 3 cyan 5 Magenta Table 6 - Input signal specification for image stability Input signals 96 R G B 100 100 100 100 100 50 50 100 100 50 100 50 100 50 100 100 50 50 50 50
29、 100 50 50 50 b) The print or transparency shall be cut across the bars into two similar pieces. One of the pieces shall be used for the test, and the other shall be kept in a dark environment at a temperature less than 300 K and at a relative humidity of 50 (+10/0) % as a control piece. c) The test
30、 piece shall be placed underneath a sodium glass plate of thickness 6 mm and shall be kept for 7 days exposure to a xenon lamp giving an irradiance of 0,22 W/m2 at a wavelength of 340 nm with an ambient temperature of betwen 300 K and 310 K and a relative humidity of 50 (+10/0) %. d) The transmittan
31、ce densities or reflectance densities of the test piece shall be measured every 24 h for 7 days. The microdensitometer shall be in accordance with status A as specified in IS0 5-3. The results of the measurenient, D,(s : A Horizontal: 96 5.1 1 Flatfield modulation 5.1 1.1 Characteristics to be deter
32、mined The image modulation when a constant achromatic signal is reproduced as uniform grey prints or transparencies. 5.1 1.2 Measurement procedure . a), The achromatic signal which produces prints or transparencies of reflectance optical density D, (SA : V) - 0,8 or trans- optical density D, (SEI :
33、Vr) - 0,8 shall be generated. The measuring instrument shall have the same spectral response as the CIE standard luminous efficiency function, V( A). b) The signal level shall be adjusted to the required level by interpolating the data obtained in 5.5. c) The image corresponding to the constant sign
34、al shall be measured in the longitudinal direction for its transmittance or reflectance optical density using a micro densitometer with a slit aperture having the same spectral response as the CIE standard luminous efficiency function, V(A). The width of the slit aperture, x, shall be constrained by
35、: 1 xs- 2fH wheref, is the highest spatial frequency being detected. The height of the slit, y, shall be constrained by: y z Nx where N is the number of data samples collected in the scan. The slit shall be stepped across the image with a step pitch, z, given by Xn, as shown in figure 10. CENELEC EN
36、*bl*blO 96 3404583 OL77ZLl 9LT Page 26 EN 61610 : 1996 Direction of rccm Figure 10 - Shape of slit and direction of scan The number of data samples, N, shall be constrained by: wheref, is the lowest spatial frequency being detected. d) The average, p, of all data values collected in step c) shall be
37、 computed and it shall be subtracted from each data value as follows: ri - D, - p i - ON-I where D is the sample data; r is the residual data. e) The squared magnitude of the discrete fourier transform Fi) of the residual data shall be computed to produce the first estimate of the flat field modulat
38、ion, S, in the longitudinal direction, given by: where II II indicates the magnitude of a complex number; i is the imaginary unit satisfying i* = - i. f) Steps c) through e) shall be repeated 99 more times over non-overlapping image areas and the ensemble average over all 100 estimates of the flat field modulation shall be computed, as indicated by the formula: Sko) j - ON-l 1 So) - - 100 k-l
