module Data.Prizm.Color.CIE.XYZ ( toRGB , toRGBMatrix , toLAB , toLCH , toHex , fromRGB , fromHex , fromLAB , fromLCH ) where import Control.Applicative import Data.Prizm.Types import Data.Prizm.Color.Transform import Data.Prizm.Color.Matrices.XYZ import Data.Prizm.Color.CIE (v1, v2, refWhite) import qualified Data.Prizm.Color.SRGB as S import {-# SOURCE #-} qualified Data.Prizm.Color.CIE.LAB as LB import {-# SOURCE #-} qualified Data.Prizm.Color.CIE.LCH as LC -- | @transformRGB@ transform an XYZ integer to be computed against -- the xyzToRGB matrix. transformRGB :: Double -> Integer transformRGB v | v > 0.0031308 = min (round ((1.055 * (v ** (1 / 2.4)) - 0.055) * 255)) 255 | otherwise = min (round ((12.92 * v) * 255)) 255 transformLAB :: Double -> Double transformLAB v | v > v1 = v ** (1/3) | otherwise = (v2 * v) + (16 / 116) -- | @toRGB@ convert a CIE color to an SRGB color. -- -- This function uses the default d65 illuminant matrix. toRGB :: CIEXYZ Double -> RGB Integer toRGB = (toRGBMatrix d65SRGB) -- | @toRGBMatrix@ convert an XYZ color to an SRGB color using a -- provided matrix. toRGBMatrix :: XYZtoRGB -> CIEXYZ Double -> RGB Integer toRGBMatrix (XYZtoRGB m) (CIEXYZ x y z) = let t = ZipList ((/100) <\$> [x,y,z]) [r,g,b] = (transformRGB) <\$> ((zipTransform t) <\$> m) in (S.clamp) <\$> RGB r g b -- | @fromRGB@ convenience function for converting to XYZ from RGB. fromRGB :: RGB Integer -> CIEXYZ Double fromRGB = S.toXYZ -- | @toHex@ convenience function for converting XYZ straight to HEX. toHex :: CIEXYZ Double -> Hex toHex = S.toHex . toRGB -- | @fromHex@ convenience function for converting to XYZ from HEX. fromHex :: Hex -> CIEXYZ Double fromHex = S.toXYZ . S.fromHex -- | @toLAB@ convert an XYZ color to a LAB color. -- -- This function uses the default reference white (2deg observer, d65 -- illuminant). toLAB :: CIEXYZ Double -> CIELAB Double toLAB (CIEXYZ x y z) = let v = getZipList \$ ZipList ((/) <\$> [x,y,z]) <*> ZipList refWhite [tx,ty,tz] = (transformLAB) <\$> v l = (116 * ty) - 16 a = 500 * (tx - ty) b = 200 * (ty - tz) in CIELAB l a b -- | @fromLAB@ convenience function for converting to XYZ from LAB. fromLAB :: CIELAB Double -> CIEXYZ Double fromLAB = LB.toXYZ -- | @toLCH@ convenience function for converting XYZ straight to LAB. toLCH :: CIEXYZ Double -> CIELCH Double toLCH = LB.toLCH . toLAB fromLCH :: CIELCH Double -> CIEXYZ Double fromLCH = LC.toXYZ