Physics:Tristimulus colorimeter
A tristimulus colorimeter, colloquially shortened to colorimeter, is used in digital imaging to profile and calibrate output devices. It takes a limited number of wideband spectral energy readings along the visible spectrum by using filtered photodetectors; e.g. silicon photodiodes.[1]
A colorimeter with the known value of absolute error allows measuring (x,y)-chromaticity coordinates in red, green, blue and white colors. Measured values are used for calculation of LCD profile coefficients.[2]
Originally, three glass filters whose transmittance spectra mimicked the CIE color matching functions (shown below) were employed.[3] A filter bank may be used to decompose the individual color matching functions if more accuracy is desired.[4]
A camera or colorimeter is said to be colorimetric if it satisfies the Luther condition by Robert Luther (1868–1945) (also called the "Maxwell–Ives criterion"),[5] reducing observer metamerism color errors, if the product of the spectral responsivity of the photoreceptor and the spectral transmittance of the filters is a linear combination of the CMFs.[6]
A colorimeter or a digital camera with a color filter array can, under certain conditions, be used as an alternative to a spectrophotometer.[7][8]
The illuminant and observer conditions should be specified when citing a measurement (e.g. D65/10°).[9]
The quality of a colorimeter may be assessed using the means in CIE publication 179:2007.[10]
There are various calibration methods for tristimulus colorimeters.[11]
Color sensor of a colorimeter
The CIE 1931 XYZ color matching functions
References
- ↑ Schanda, János; George Eppeldauer; Georg Sauter (2007). "Tristimulus Color Measurement of Self-Luminous Sources". in János Schanda. Colorimetry: Understanding the CIE System. Wiley Interscience. doi:10.1002/9780470175637.ch6. ISBN 978-0-470-04904-4.
- ↑ Zharinov I.O., Zharinov O.O. (2015). "Method of software-based compensation of technological variation in chromaticity coordinates of LCD panels". Scientific and Technical Journal of Information Technologies, Mechanics and Optics 15 (3): 387–397. doi:10.17586/2226-1494-2015-15-3-387-397. http://ntv.ifmo.ru/en/article/13462/metod_programmnoy_kompensaciitehnologicheskogo_razbrosa_koordinat_cvetnostizhidkokristallicheskih_paneley.htm.
- ↑ Hunter, Richard Sewall (September 1942). "Photoelectric tristimulus colorimetry with three filters". JOSA 32 (9): 509–538. doi:10.1364/JOSA.32.000509. http://www.opticsinfobase.org/abstract.cfm?URI=josa-32-9-509.
- ↑ Eppeldauer, George (Nov–Dec 1998). "Spectral Response Based Calibration Method of Tristimulus Colorimeters". Journal of Research of the National Institute of Standards and Technology 103 (6): 615–619. doi:10.6028/jres.103.040. PMID 28009362. PMC 4890952. http://nvl.nist.gov/pub/nistpubs/jres/103/6/j36epp.pdf.
- ↑ Luther, Robert T.D. (1927). "Aus dem Gebiet der Farbreizmetrik". Zeitschrift für technische Physik 8: 540–558.
- ↑ Ohta, Noboru; Robertson, Alan R. (2005). "Measurement and Calculation of Colorimetric Values". Colorimetry. John Wiley & Sons, Ltd.. p. 154. doi:10.1002/0470094745.ch5. ISBN 978-0-470-09472-3.
- ↑ Imai, Francisco H.; Berns, Roy S. (1999). "Spectral estimation using trichromatic digital cameras". Proceedings of the International Symposium on Multispectral Imaging and Color Reproduction for Digital Archives 42. http://www.cis.rit.edu/research/mcsl2/online/Spectral/TechnicalPapers/SpecEstimRGBCamera_Chiba99.pdf. Retrieved 2008-05-06.
- ↑ Solli, Martin (16 December 2004). Filter characterization in digital cameras (PDF) (Thesis). Retrieved 2008-05-06.
- ↑ Sangwine, Stephen J.; Horne; Robin E. N. (1998). The Colour Image Processing Handbook. Springer. p. 41. ISBN 0-412-80620-7. https://books.google.com/books?id=oEsZiCt5VOAC&q=%22tristimulus+colorimeter%22+OR+spectrocolorimeter&pg=PA42.
- ↑ CIE TC 2-16 "Characterization of the Performance of Tristimulus Colorimeters" (2007). Methods for characterising tristimulus colorimeters for measuring the colour of light. Publication 179:2007. Vienna: CIE Central Bureau. ISBN 978-3-901906-60-2. http://www.cie.co.at/publ/abst/179-07.html.
- ↑ Gardner, James L. (May–June 2007). "Comparison of Calibration Methods for Tristimulus Colorimeters". Journal of Research of the National Institute of Standards and Technology 112 (3): 129–138. doi:10.6028/jres.112.010. PMID 27110460. PMC 4656001. Archived from the original on 2008-05-28. https://web.archive.org/web/20080528051448/http://nvl.nist.gov/pub/nistpubs/jres/112/3/V112.N03.A01.pdf.
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