Összefoglalás di L fénysűrűség da cd/m 2 fényáram lm d I fényerősség d/dcd P A P pontot körülvevő területelem, da Megvilágítás E d da
Hazai és nemzetközi színbizottságok 1. CIE (Commission Internationale de l Éclairage,1913) 2. AIC (Association Internationale de la Couleur, 1967) Albizottságok: Színek Színes környezet A színek rendszerezése A színek oktatása Látási illuziók és effektusok Színlátási hibák 3. OSA (Optical Society of America) 4. ISCC (Inter Society Color Council), USA
Hazai és nemzetközi színbizottságok 5. ICC (International Color Consortium) www.color.org
Each device sees color differently Image display Photographic printer How can we convert colors from one device to another? Ink jet printer Digital camera Scanner Printing press FujiFilm 2002
Device dependent solution Image display Photographic printer Colour transform jungle Ink jet printer Digital camera Scanner Printing press M x N transforms required FujiFilm 2002
Device-independent solution Image display Photographic printer TAG Color transform for device to standard color space and from standard color space to device Ink jet printer TAG TAG Standard colour space TAG TAG TAG Digital camera Scanner Printing press M + N transforms required FujiFilm 2002
TOWARDS A NEW CENTURY OF LIGHT CIE Commission Internationale de l Éclairage
IT IS ABOUT:::::: LIGHT & VISION & COLOUR SCIENCE & STANDARDS KNOWLEDGE TRANSFER & QUALITY ASSURANCE
THE COMMISSION 1400 Experts (Scientists, Standardization Officers, Lighting Designers in more than 50 Countries 41 National Committees in all Continents 15 Industry Members 7 Divisions 129 Scientific Project Groups (Technical Committees)
THE BRAND Recognized worldwide as being the best authority on the subject High Quality Independent & Unbiased Setting Standards in Science & Applications
OBJECTIVES to provide an international forum to develop basic standards and procedures to provide guidance in the development of international, national and regional standards to provide publications to maintain liaisons and technical interaction with other international organizations working in similar subject areas
MILESTONES IN HISTORY 1900: World Exhibition in Paris- Commission de la Photométrie 1913: Commission International de l Eclairage 1986: Central Bureau established in Vienna 2013: 100th anniversary Paris 2017: Jeju, South Korea
STAKEHOLDERS Lighting Designers Metrology Institutions Industry Standards Organizations Academia CIE International Organizations
PROCESS MODEL Knowledge Generation Knowledge Publishing Knowledge Transfer Quality Assurance
DIVISIONS 1. Vision and Colour 2. Measurement of Light and Radiation 3. Interior Environment and Lighting Design 4. Lighting and Signalling for Transport 5. Exterior Lighting and Other Applications 6. Photobiology and Photochemistry 8. Image Technology
TECHNICAL COMMITTEES Scientific Heart of the Organisation Semi-permanent Units Clear Terms of Reference, Workplan and Schedule Aims at Publication of a Standard, Technical Report or Guide
LIAISONS Bureau International de Poids et Mesures (BIPM) European Standardization Committee (CEN) International Standards Organization (ISO) International Electrotechnical Commission (IEC) Lighting Urban Cities International (LUCI) Professional Lighting Designers Association (PLDA)
INTERNATIONAL STANDARDIZATION
COMMISSION INTERNATIONALE DE L ECLAIRAGE (CIE) the world s leading organization for the preparation and publication of International Standards in Light/Lighting/Vision/Colour Non-governmental organization Central Secretariat in Vienna 41 members, 7 Divisions, and app. 130 Technical Committees.
ROLE IN STANDARDIZATION ISO delegated standardization in lighting and colour to CIE IEC develops PRODUCT STANDARDS (IEC TC34) CIE develops FUNDAMENTAL AND APPLICATION STANDARDS
http://www.cie.co.at/
http://eilv.cie.co.at/ 17-491 germicidal radiation optical radiation capable of inactivating or killing pathogenic micro-organisms Equivalent term: "microbiocidal radiation" 17-97 blue light hazard potential for a photochemically induced retinal injury resulting from optical radiation exposure at wavelengths primarily between 400 nm and 500 nm NOTE 1 This damage mechanism dominates over the thermal damage mechanism for exposure durations exceeding 10 s. NOTE 2 The action spectrum extends into the UV-A for persons without a normal UV-A absorbing lens. Abbreviation: "BLH" 17-720 luminance threshold lowest luminance of a stimulus which enables it to be perceived Unit: cd m -2 NOTE The value depends on field size, surround, state of adaptation, methodology, and other viewing conditions.
CIE 212:2014 Guidance towards Best Practice in Psychophysical Procedures Used when Measuring Relative Spatial Brightness
TC1-89 Enhancement of Images for Colour Defective Observers
TC2-63 Spectral mismatch with photometers Photometer head 1.0 <Example> -26 % V( ) s( ) +17 % 0.5 0.0 400 450 500 550 600 650 700 750 Wavelength (nm) This case would cause -45 % error! To avoid this, Use standard LEDs of the same color (many std LEDs are needed). or Apply mismatch correction factors (not easy).
TC1-95: Whiteness formula
CIE TC1-01 Colour mixing Additive subtractive colour mixing
Colorimetry Additive colour mixture
Grassmann s laws To specify a colour match three independent variables are necessary and sufficient For additive mixture of colour stimuli, only their tristimulus values are relevant, not their spectral composition In additive mixtures of colour stimuli, if one or more components are gradually changed, the resulting tristimulus values also change gradually
Colour equation Positive additivity C RR GG BB
CIE colorimetry The colour equation Condition 1: 2 bipartite visual field, central fixation and dark surround. Matching (reference, primary) stimuli: Red (R): 700 nm, Green (G): 546,1 nm and Blue (B): 435,8 nm C R( R) + G( G) + B( B)
Colour matching experiment
The colour equation But i.e.: C(520 nm ) R( R) G( G) + B( B) C R( R) + G( G) + B( B) C R( R) + G( G) + B( B)
Practical realization of negative matching stimulus
Tristimulus values and colour matching functions rel. sens. r ( ), g ( ) and b ( ) r2 g2 b2 400 500 600 700 wavelength, nm λr =700,0 λg =546,1 λb =435,8
X,Y,Z colour space CIE 1931 Standard Colorimetric Observer 1.the tristimulus values of the colour stimulus of the equienergetic spectrum should again be equal; 2.all the photometric information (luminance, if the stimulus is measured in radiance units) should be in a single value, i.e. one of the colour matching functions should be equal with the V()-function; 3.the tristimulus values of all real colours should be positive and the volume of the tetrahedron should be as small as possible.
RGB - XYZ matrix transformation X 2,76888 1,75175 1,13016 R Y 1,00000 4,59070 0,06010 G Z 0,00000 0,05651 5,59427 B The inverse transformation: 0,41846-0,15866-0,08283-0,09117 0,25243 0,01571 0,00092-0,00255 0,17860
The colour matching functions
The tristimulus values The X, Y, Z tristimulus values of a colour stimulus (S()): 780 nm X k S( ) x( ) d, Y k S( ) y( ) d, 380 nm 780 nm Z k S( ) z( ) d 380 nm 780 nm 380 nm with k = 683 lm/w for photometric quantities.
Chromaticity co-ordinates x X X Y Z, y X Y Y Z, z X Z Y Z where, as x + y + z = 1
Chromaticity diagram
Chromaticity diagram E: equi-energy chromaticity R, G, B: chromaticity of real primaries
Mixing and visualising colours in the chromaticity diagram achromatic (N for neutral) "white point dominant (complementary) wavelength ( D ), correlate of hue excitation purity, correlate of saturation
Excitation purity For chromaticity point C 0,9 0,8 520 540 pe=(yc - yn)/(ydw - yn) or pe=(xc - xn)/(xdw - xn) 0,7 0,6 0,5 CW 500 560 580 y 0,4 0,3 0,2 DW C N C' 600 620 700 0,1 480 P 0 460 0 380 0,2 0,4 0,6 0,8
Description of a colour stimulus Tristimulus values, X, Y, Z. Chromaticity and luminance: Y (or L), x, y. Further descriptors: Luminance: L, dominant (or complementary) wavelength: D excitation purity: p e
CIE 1964 Standard Colorimetric Observer Macula lutea or yellow spot 10 field of vision X 10 Z 10 k k 780nm 380nm S( ) x 780nm 380nm 10 S( ) z and X x 10 10 X Y Z 10 10 10 ( )d, 10 ( )d Y 10 k 780nm 380nm k = Y10 Y, y 10, 10 X Y Z 10 10 10 S( ) y z 10 X 10 ( )d, Z Y 10 10 10
CIE 1931 and 1964 Standard Colorimetric Observers
The CIE x,y diagram with ellipses representing small colour differences MacAdam ellipses
The CIE system of colorimetry CIE 1976 uniform chromaticity diagram colour temperature, Tc & correlated Tc, TCC Colorimetry of surface colours CIE standard illuminants and sources CIE colour spaces CIELUV space CIELAB space CIE 1994 colour difference CIE DE2000 colour difference Brightness - luminance ratio
u,v chromaticity diagram 0,6 0,5 500 550 huv 600 650 700 0,4 Sn v' 0,3 0,2 C 0,1 0 450 400 0 0,1 0,2 0,3 0,4 0,5 0,6 0, u'
Uniform colour scales u' = 4X / (X+15Y+3Z) = 4x / (-2x+12y+3) v' = 9Y / (X+15Y+3Z) = 9y / (-2x+12y+3) u = u', v = (2/3)v' CIE 1976 u,v hue angle: h uv = arctg[(v' - v' n ) / (u' - u' n )] = v* / u* The CIE 1976 u,v saturation: s uv = 13[(u' - u' n ) 2 + (v' - v' n ) 2 ] 1/2
u,v chromaticity diagram
CIE 1976 (L*a*b*) colour space, CIELAB colour space L* 116(Y/Y n ) 1/3-16 a* 500 ( X/X n ) 1/3 - (Y/Y n ) 1/3 b* 200 (Y/Y n ) 1/3 - (Z/Z n ) 1/3 for X/X n > 0,008856 Y/Y n > 0,008856 Z/Z n > 0,008856
CIE 1976 (L*a*b*) colour space, CIELAB colour space
CIE 1976 a,b colour difference and CIELAB components Colour difference: E ab (L*) 2 + (a*) 2 (b*) 2 1/2 CIE1976 a,b chroma: C ab * (a* 2 + b* 2 ) 1/2 CIE 1976 a,b hue-angle: h a arctan (b*/a*) CIE 1976 a,b hue-difference: H ab * (E ab *) 2 - (L*) 2 - (C ab*)2 1/2
Perceived colour differences E ab * experimental values 0...0,5 not perceivable 0,5...1,5 slightly perceivable 1,5...3,0 perceivable 3,0...6,0 well perceivable 6,0...12,0 large
Színhőmérséklet
Hőmérsékleti sugárzás o o o A kellően nagy hőmérsékletű test az energia egy részét fény formájában is sugározza. A kisugárzott fényenergia a test hőmérsékletének növelésével növekszik. Azonos hőmérsékletű testek közül az sugároz legjobban, amelyik a sugárzást legjobban elnyeli.
Kirchoff-törvény Abszorpcióképesség: α(λ,t) [dimenzió nélkül] Emisszióképesség: e(λ,t) W 2 m sr Kirchoff (1860):
Abszolút fekete test Abszolút fekete testnél: α(λ,t)=1 Megvalósítása: gondosan hőszigetelt, fekete belső felületű platina cső, indukciós fűtéssel
Abszolút fekete test
Hőmérsékleti sugárzás
Planck-törvény 1 2 ), ( 5 2 T k h c e c h T E c: a fény sebessége vákuumban ~3 10 8 m/s h: a Planck állandó 6,626176 10-34 Js k: a Boltzmann állandó 1,38 10-23 J/K
Wien-féle eltolódási törvény
Stefan-Boltzman-törvény Abszolút fekete test által kisugárzott energia: E T 4 E E( ) d : Stefan-Boltzman áll.
Hőmérsékleti sugárzó fényforrások e( ) ( ) T 4 ε(λ):emissziós tényező szürke sugárzó, ha ε(λ)=constans szelektív sugárzó, ha ε(λ) constans
Színhőmérséklet
Színkoordináták
Színkoordináták Z Y X Z z ; ; Z Y X Y y Z Y X X x 780 380 ) ( ) ( d x X 780 380 ) ( ) ( d y Y 780 380 ) ( ) ( d z Z
CIE színrendszer 1931 xy
Korrelált színhőmérséklet - CCT
Színhőmérséklet Meleg < 3500K Semleges 3500K 5500K Hideg > 5500K
Színhőmérséklet 1500 K 2680 K 3000 K 3200 K 3400 K 5000 K Gyertya 40 W-os izzó 200 W-os izzó Naplemente 1 órával naplemente előtt Xenon lámpa 5500-5600 K Vaku 6500-7500 K Déli napfény 9000-12000 K Kék ég