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Test rework, bugfixes and more tests

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nxshock 2017-06-26 23:12:48 +05:00
parent 1cf1415b29
commit 28d09be6b5
22 changed files with 240 additions and 45 deletions
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27
colorconversion.go
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@ -5,10 +5,13 @@ import (
"math"
)
func rgbtoXYZ(r, g, b uint32) (x, y, z float64) {
varR := float64(r) / 255
varG := float64(g) / 255
varB := float64(b) / 255
// colorToXYZ returns CIE XYZ representation of color.
// https://en.wikipedia.org/wiki/Color_model#CIE_XYZ_color_space
func colorToXYZ(color color.Color) (x, y, z float64) {
r, g, b, _ := color.RGBA()
varR := float64(r>>8) / 255
varG := float64(g>>8) / 255
varB := float64(b>>8) / 255
if varR > 0.04045 {
varR = math.Pow((varR+0.055)/1.055, 2.4)
@ -28,16 +31,15 @@ func rgbtoXYZ(r, g, b uint32) (x, y, z float64) {
varB = varB / 12.92
}
varR = varR * 100
varG = varG * 100
varB = varB * 100
x = varR*41.24 + varG*35.76 + varB*18.05
y = varR*21.26 + varG*71.52 + varB*7.22
z = varR*1.93 + varG*11.92 + varB*95.05
x = varR*0.4124 + varG*0.3576 + varB*0.1805
y = varR*0.2126 + varG*0.7152 + varB*0.0722
z = varR*0.0193 + varG*0.1192 + varB*0.9505
return x, y, z
}
// xyztoLAB converts CIE XYZ color space to CIE LAB color space
// https://en.wikipedia.org/wiki/Lab_color_space#CIELAB-CIEXYZ_conversions
func xyztoLAB(x, y, z float64) (l, a, b float64) {
refX, refY, refZ := 95.047, 100.000, 108.883 // Daylight, sRGB, Adobe-RGB, Observer D65, 2°
@ -68,7 +70,8 @@ func xyztoLAB(x, y, z float64) (l, a, b float64) {
return l, a, b
}
// colorToLAB returns LAB representation of any color (without aplha)
// https://en.wikipedia.org/wiki/Lab_color_space
func colorToLAB(color color.Color) (l, a, b float64) {
cr, cg, cb, _ := color.RGBA()
return xyztoLAB(rgbtoXYZ(cr, cg, cb))
return xyztoLAB(colorToXYZ(color))
}