221:
The spectral similarity index (SSI) of 2016 is a scale that completely forgoes the comparison of color samples, instead directly comparing the SPDs of one light source to the reference. Its developers argue that difference among cameras mean that TLCI can only describe three-chip television cameras,
106:
2016 (revised 2020). Ditches the concept of color samples in CRI and TLCI to directly address the shape of the spectrum. As there are no color samples, SSI doesn't measure color rendering, but is included here because it is often used to indicate the potential color rendering quality of a test light
229:
The SSI is calculated by taking two integrated, normalized SPDs in the 5-nm intervals from 375 to 675 nm and finding a weighted relative difference between them. This weighted relative difference is convolved, and the magnitude of the result is translated into a 100-point value. A low SSI only
129:
Researchers used daylight as the benchmark to which to compare color rendering of electric lights. In 1948, daylight was described as the ideal source of illumination for good color rendering because "it (daylight) displays (1) a great variety of colours, (2) makes it easy to distinguish slight
269:(accuracy of color reproduction) to describe other aspects of color rendering. This extra information allows for, e.g. fidelity to be sacrificed for vividness of skin tones under a certain design criterion. Three reference design intents and priority levels are defined in TM-30 Annex E.
120:, 2015 (revised 2020). A metric related to CRI with updated color transformation, more (99) color samples, and scoring for additional "pleasantness" factors such as gamut size and hue shift. Still uses human participants. Endorsed by CIE in 2015 to replace CRI.
169:. Eight samples of varying hue would be alternately lit with two illuminants, and the color appearance compared. Since no color appearance model existed at the time, it was decided to base the evaluation on color differences in a suitable color space,
212:
is simulated using known reflectivities and the color curves of an average HDTV camera and display. The differences are calculated in CIEDE2000. With the TLMF, the reference is not specified by a CCT, but by a user directly.
164:
The color rendering index (CRI) of 1974 is the product of a CIE committee's study on the topic of color rendering. It uses the
American colorimetric approach with a panel of human subjects instead of requiring
529:"[Tech 3355] Method for the Assessment of the colorimetric properties of luminaires: The Television Lighting Consistency Index (TLCI-2012) &Television Luminaire Matching Factor (TLMF-2013)"
193:. At that time, the relatively broad-band nature of light sources meant that the CRI still approximated the color rendering for television cameras, an assumption quickly broken by the advent of
254:, a gamut shape graph, and detailed values for chroma, hue, and color fidelity for each of the 16 hue ranges, plus color fidelity scores for each of the 99 sample colors. It uses the
238:
TM-30 is the current (as of 2021) CIE recommended measure for color rendering as perceived by humans. It generates a large set of outputs, including an overall fidelity index (R
290:
A revision of the CRI to account for the obsolescence/loss of original color samples and some improvements in colorimetry. Uses ColorChecker samples, CIELAB, and CIECAT94.
201:
re-introduced the concept of a television lighting consistency index (TLCI) in 2012, followed by a television luminaire matching factor (TLMF) in 2013 for mixed lights.
75:
A wide variety of quantitative measures have been devised to measure the color rendering of a light source, to the human eye or to the camera. Notable ones include:
177:
before comparing to the reference illuminant. Each color difference was translated to a sub-score, eight of which are averaged to produce the final score of R
103:
277:
Before the aforementioned scales are devised to replace CRI, a number of other measures have been proposed. None of them have seen wide use, however:
55:
46:) in comparison with an ideal or natural light source. Light sources with good color rendering are desirable in color-critical applications such as
489:
265:
As with other newer scales, TM-30 is calculated from a SPD with reference to a SPD of the same CCT. The uniqueness of TM-30 is that it goes beyond
517:
Sproson, W. N. & Taylor, E. W. (1971). A colour television illumination consistency index. BBC Research
Department Report 1971-45
640:
230:
warns of potential color-rendering issues, but neither confirms the presence of one nor indicates what errors are likely to occur.
82:(CRI), CIE 1974. Currently acknowledged as flawed, but still widely used for consumer lighting. Updated 1999, but rarely followed.
204:
To calculate a TLCI, a full measure of the spectral power distribution (SPD) of the light source is first taken. From this SPD a
114:
425:
174:
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578:"Tutorial: Background and Guidance for Using the ANSI/IES TM-30 Method for Evaluating Light Source Color Rendition"
406:
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area. Use in conjunction with a fidelity measure (such as CRI) predicts preference better than using either alone.
208:(CCT) is found, which provides the reference illuminant. Under the test and reference illuminant, an image of the
733:. Vol. 8, no. 2. Alliance for Solid-State Illumination Systems and Technologies. March 2010. p. 6
92:
2012. Address the spectral response of cameras and screens, which can have significantly different results with
222:
not the more-varied spectral sensitivities of single-chip digital cinema, still cameras, or film. (In theory,
66:
of objects by conscious or subconscious comparison with their color appearance under a reference illuminant.
667:
666:
Davis, W.; Ohno, Y. (2005). Ferguson, Ian T.; Carrano, John C.; Taguchi, Tsunemasa; Ashdown, Ian E. (eds.).
452:. (Eindhoven: Philips Gloeilampenfabrieken (Philips Industries) Technical and Scientific Literature Dept.).
449:
Physical aspects of colour; an introduction to the scientific study of colour stimuli and colour sensations
687:
615:
556:
497:
281:
159:
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to accurately reproduce colors. European researchers attempted to describe illuminants by measuring the
93:
79:
853:. International Lighting and Colour Conference, Cape Town, South Africa, Nov 2–5, 2003. pp. 76–85.
829:
798:
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170:
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Around the middle of the 20th century, color scientists took an interest in assessing the ability of
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293:
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141:(SPD) in "representative" spectral bands, whereas their North American counterparts studied the
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63:
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731:
Recommendations for
Specifying Color Properties of Light Sources for Retail Merchandising
189:
As early as 1971, an analogue of CRI for televisions have been devised by workers at the
833:
802:
771:
683:
868:
862:
787:
Crawford, Brian Hewson (December 1959). "Measurement of color rendering tolerances".
756:
Barnes, Bentley T. (December 1957). "Band
Systems for Appraisal of Color Rendition".
709:
601:
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shades of colour, and (3) the colours of objects around us obviously look natural".
251:
209:
194:
142:
35:
593:
646:
616:"Using TM-30 to Improve Your Lighting Design – Illuminating Engineering Society"
361:
528:
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841:
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has been adopted by the CIE as CIE 224:2017 "color fidelity index" (CFI).
307:
255:
17:
818:
Nickerson, Dorothy (January 1960). "Light sources and color rendering".
701:
344:"Neonatal intensive care unit lighting: Update and Recommendations"
317:
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39:
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also introduce variations that are hard to be captured by TLCI.)
820:
789:
758:
385:
299:
190:
173:. The residual difference in chromaticity is resolved with a
496:. Troy, NY: Rensselaer Polytechnic Institute. Archived from
674:. Fifth International Conference on Solid State Lighting.
555:
Academy of Motion
Picture Arts and Sciences (2020-09-16).
85:
411:
Oscars.org | Academy of Motion
Picture Arts and Sciences
107:
source as compared to a reference source. Published as
557:"Academy Spectral Similarity Index (SSI): Overview"
635:, Publication 135/2, Vienna: CIE Central Bureau,
358:"CIE 17.4-1987 International Lighting Vocabulary"
145:effect of the illuminants on reference objects.
42:of various objects faithfully (i.e. to produce
99:
475:
27:Ability of a light source to reproduce colors
8:
571:
569:
386:"Television Lighting Consistency Index 2012"
668:"Toward an improved color rendering metric"
306:. Uses more saturated samples, CIELAB, and
632:Colour rendering (TC 1–33 closing remarks)
851:Colour rendering, past – present – future
691:
550:
548:
463:
849:Schanda, János; Sándor, Norbert (2003).
471:
56:International Commission on Illumination
426:"Evaluating Color Rendering With TM-30"
335:
488:Rea, M.; Deng, L.; Wolsey, R. (2004).
467:
380:
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401:
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185:Television lighting consistency index
86:Television lighting consistency index
7:
38:refers to its ability to reveal the
576:Royer, Michael P. (16 March 2021).
462:American approach is expounded in
25:
407:"Spectral Similarity Index (SSI)"
424:Michael Royer (March 31, 2016).
466:, and the European approach in
302:-proposed replacement for CRI R
62:Effect of an illuminant on the
175:chromatic adaptation transform
1:
594:10.1080/15502724.2020.1860771
527:European Broadcasting Union.
433:ENERGY STAR Webinar (US DOE)
206:correlated color temperature
476:Schanda & Sándor (2003)
310:. Modifications to scoring.
199:European Broadcasting Union
139:spectral power distribution
890:
478:for a historical overview.
157:
117:
490:"Light Sources and Color"
217:Spectral similarity index
100:Spectral similarity index
54:. It is defined by the
842:10.1364/JOSA.50.000057
811:10.1364/JOSA.49.001147
780:10.1364/JOSA.47.001124
494:NLPIP Lighting Answers
313:Gamut area index, 2010
68:
160:Color rendering index
154:Color rendering index
94:high-CRI LED lighting
80:Color rendering index
71:Quantitative measures
60:
44:illuminant metamerism
446:P. J. Bouma (1948).
834:1960JOSA...50...57N
803:1959JOSA...49.1147C
772:1957JOSA...47.1124B
684:2005SPIE.5941..283D
294:Color quality scale
197:. As a result, the
258:color space. The R
58:(CIE) as follows:
797:(12): 1147–1156.
766:(12): 1124–1129.
724:"Color Rendering"
702:10.1117/12.615388
250:) for changes in
167:spectrophotometry
135:artificial lights
16:(Redirected from
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64:color appearance
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588:(2): 191–231.
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392:. 31 May 2016.
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735:. Retrieved
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678:: 59411G–1.
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651:, retrieved
647:the original
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629:CIE (1999),
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535:. Retrieved
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502:. Retrieved
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366:. Retrieved
362:the original
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273:Other scales
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220:
210:ColorChecker
203:
195:LED lighting
188:
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143:colorimetric
132:
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74:
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36:light source
31:
29:
749:Works cited
537:16 November
390:tech.ebu.ch
863:Categories
737:2020-09-14
672:Proc. SPIE
653:2008-07-16
504:2010-06-17
368:2008-02-19
330:References
308:CMCCAT2002
224:color gels
125:Background
710:121431482
688:CiteSeerX
602:233697915
256:CAM02-UCS
18:IES TM-30
874:Lighting
267:fidelity
246:index (R
88:(TLCI),
830:Bibcode
799:Bibcode
768:Bibcode
680:Bibcode
102:(SSI),
708:
690:
639:
600:
582:LEUKOS
474:. See
470:, and
296:, 2005
287:, 1999
252:chroma
171:CIEUVW
149:Scales
40:colors
869:Color
727:(PDF)
706:S2CID
598:S2CID
560:(PDF)
532:(PDF)
429:(PDF)
318:gamut
244:gamut
234:TM-30
118:TM-30
111:2122.
109:SMPTE
104:AMPAS
34:of a
821:JOSA
790:JOSA
759:JOSA
676:5941
637:ISBN
539:2021
300:NIST
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282:R96
191:BBC
115:IES
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