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colors.yiq: expanded the number of digits in the coefficients for the rgba>yiqa conversions so that they match the FCC NTSC versions.

db4
John Benediktsson 2013-09-18 16:17:07 -07:00
parent 183508b852
commit a3e669aab3
1 changed files with 13 additions and 11 deletions
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24
extra/colors/yiq/yiq.factor
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@ -1,7 +1,8 @@
! Copyright (C) 2012 John Benediktsson ! Copyright (C) 2012 John Benediktsson
! See http://factorcode.org/license.txt for BSD license ! See http://factorcode.org/license.txt for BSD license
USING: accessors colors combinators kernel math math.order ; USING: accessors colors combinators kernel locals math
math.order ;
IN: colors.yiq IN: colors.yiq
@ -17,16 +18,17 @@ M: yiqa >rgba
{ {
[ y>> ] [ in-phase>> ] [ quadrature>> ] [ alpha>> ] [ y>> ] [ in-phase>> ] [ quadrature>> ] [ alpha>> ]
} cleave [ } cleave [
[ [ 0.948262 * ] [ 0.624013 * ] bi* + + ] [ [ 0.9468822170900693 * ] [ 0.6235565819861433 * ] bi* + + ]
[ [ 0.276066 * ] [ 0.639810 * ] bi* + - ] [ [ 0.27478764629897834 * ] [ 0.6356910791873801 * ] bi* + - ]
[ [ 1.105450 * ] [ 1.729860 * ] bi* - - ] [ [ 1.1085450346420322 * ] [ 1.7090069284064666 * ] bi* - - ]
3tri [ 0.0 1.0 clamp ] tri@ 3tri [ 0.0 1.0 clamp ] tri@
] dip <rgba> ; inline ] dip <rgba> ; inline
: rgba>yiqa ( rgba -- yiqa ) :: rgba>yiqa ( rgba -- yiqa )
>rgba-components [ rgba >rgba-components :> ( r g b a )
[ [ 0.30 * ] [ 0.59 * ] [ 0.11 * ] tri* + + ] 0.30 r * 0.59 g * 0.11 b * + + :> y
[ [ 0.60 * ] [ 0.28 * ] [ 0.32 * ] tri* + - ] r y - :> r-y
[ [ 0.21 * ] [ 0.52 * ] [ 0.31 * ] tri* - - ] b y - :> b-y
3tri 0.74 r-y * 0.27 b-y * - :> i
] dip <yiqa> ; 0.48 r-y * 0.41 b-y * + :> q
y i q a <yiqa> ;