LMS color space

LMS color space

LMS is a color space represented by the response of the three types of cones of the human eye, named after their responsivity (sensitivity) at long, medium and short wavelengths.

It is common to use the LMS color space when performing chromatic adaptation (estimating the appearance of a sample under a different illuminant).

XYZ to LMS

Typically, the color to be adapted will be specified in a color space other than LMS, but easily convertible to XYZ. The chromatic adaptation matrix in the von Kries transform method, however, is diagonal in LMS space, thus the usefulness of a transformation matrix M between spaces. The transformation matrices for some chromatic adaptation models in terms of CIEXYZ coordinates are presented here.

; Notes :
* All tristimulus values are normally calculated using the CIE 1931 2° standard colorimetric observer.cite book|first=Mark D.|last=Fairchild|title=Color Appearance Models|publisher=Wiley Interscience|isbn=978-0-470-01216-1|year=2005|edition=2E|url=http://books.google.com/books?id=8_TxzK2B-5MC&pg=PA228&lpg=PA228&dq=hunt+model+tristimulus+matrix&source=web&ots=IRmPqu6kY2&sig=I781mz7ur2tnRKcAC8aM1GH2uWk] .
* Unless specified otherwise, M is normalized (the rows add up to unity) so the tristimulus values for an equal-energy illuminant (X=Y=Z), like CIE Illuminant E, produce equal LMS values.

CMCCAT97

The CMCCAT97 color appearance model uses the Bradford transformation matrix (MB): [cite book|url=http://books.google.com/books?id=zgeuoz_muCIC&pg=PA89&lpg=PA89&dq=ciecam97s+bradford+0.8951&source=web&ots=oJQ6ylBkOz&sig=91sZ-oHpaUHNivWBVyr6XyPm2B4#PPA89,M1|title=Computational Colour Science Using MATLAB|first=Stephen|last=Westland|coauthors=Ripamonti, Caterina|publisher=Wiley Interscience|page=89|chapter=6.2.2 CMCCAT97|year=2004|isbn=0470845627]

egin{bmatrix}L\M\Send{bmatrix}=egin{bmatrix}0.8951 & 0.2664 & -0.1614 \-0.7502 & 1.7135 & 0.0367 \0.0389 & -0.0685 & 1.0296end{bmatrix}egin{bmatrix}X\Y\Zend{bmatrix}

RLAB

The RLAB color appearance model uses the Hunt-Pointer-Estevez (HPE) transformation matrix (MH) for conversion from CIE XYZ to LMS: [cite conference|title=The CIECAM02 Color Appearance Model|booktitle=IS&T/SID Tenth Color Imaging Conference|last=Moroney|first=Nathan|coauthors=Fairchild, Mark D.; Hunt, Robert W.G.; Li, Changjun; Luo, M. Ronnier; Newman, Todd|url=http://www.polybytes.com/misc/Meet_CIECAM02.pdf|location=Scottsdale, Arizona|id=ISBN 0-89208-241-0|year=2002|month=November 12|publisher=The Society for Imaging Science and Technology]

CAT97s

CIECAM97s uses a spectrally-sharpened Bradford chromatic adaptation matrix:

egin{bmatrix}L\M\Send{bmatrix}=egin{bmatrix}0.8562 & 0.3372 & -0.1934 \-0.8360 & 1.8327 & 0.0033 \0.0357 & -0.0469 & 1.0112end{bmatrix}egin{bmatrix}X\Y\Zend{bmatrix}

CAT02

The chromatic adaptation matrix (MCAT02) from the CIECAM02 model is:

egin{bmatrix}L\M\Send{bmatrix}=egin{bmatrix}0.7328 & 0.4296 & -0.1624\-0.7036 & 1.6975 & 0.0061\0.0030 & 0.0136 & 0.9834end{bmatrix}egin{bmatrix}X\Y\Zend{bmatrix}

ee also

* Color balance
* Color vision
* Luminosity function
* Trichromacy

References


Wikimedia Foundation. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Color space — A comparison of the chromaticities enclosed by some color spaces. A color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers, typically as three or four values or color components (e.g. RGB… …   Wikipedia

  • CIE 1931 color space — In the study of color perception, one of the first mathematically defined color spaces is the CIE 1931 XYZ color space, created by the International Commission on Illumination (CIE) in 1931.[1][2] The CIE XYZ color space was derived from a series …   Wikipedia

  • LMS — is an initialism with the following meanings:* Louie McCarthy Scarsbrook, a rugby league footballer for Harlequins Rugby League * London, Midland and Scottish Railway * Leamington Spa railway station, England; National Rail station code LMS *… …   Wikipedia

  • Color balance — This article is about the process applied to still images. For the equivalent process applied to video, see Color grading. The left half shows the photo as it came from the digital camera. The right half shows the photo adjusted to make a gray… …   Wikipedia

  • Color model — A color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers, typically as three or four values or color components. When this model is associated with a precise description of how the… …   Wikipedia

  • Color triangle — A 1775 color triangle …   Wikipedia

  • List of color spaces and their uses — This is a list of color spaces and their uses from the color space article. A color space consists of a color model along with a specific mapping of that model onto an absolute color space. There are a large number of color spaces in use in the… …   Wikipedia

  • CMYK color model — Color p …   Wikipedia

  • RGB color model — RGB redirects here. For other uses, see RGB (disambiguation). A representation of additive color mixing. Projection of primary color lights on a screen shows secondary colors where two overlap; the combination of all three of red, green, and blue …   Wikipedia

  • Munsell color system — The Munsell color system, showing: a circle of hues at value 5 chroma 6; the neutral values from 0 to 10; and the chromas of purple blue (5PB) at value 5. In colorimetry, the Munsell color system is a color space that specifies colors based on… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”