GRA 633 Lecture Notes - Lecture 1: Reflectance, Chromaticity, Cie 1931 Color Space
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Cyan :how many ways can you describe the colour? (order below) #2: colourimetric value (device independent) (cid:0) doesn"t depend on device. #3: indexed colour (cid:0) number or name for said colour pantone. Dependent in order to reproduce accurate copy of colour cmyk rgb. #5: descriptive colour naming common names for the colour (blue/red/purple/teal) Will always come back with same spectral reflectance percentage is luminance of object thus absorbs 98% of the wavelength. Xyz (cid:0) tristimulus values based on d50 lighting condition based on standard observer so most unknowns are eliminated. Cielab (l*a*b*) calculated from xyz based on d50 lighting and the standard observer design to be perceptually uniform. L* = lightness (0 100 )/ black - white a* = redness (+) or greenness (-) [christmas] b* = yellowness (+) or blueness (-) [ryerson] L* = 61 a* = -41 b* = -7.