This commit is contained in:
kunfei 2022-05-14 18:29:20 +08:00
parent 5b6ab8d209
commit 8b2dee847c

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@ -15,7 +15,6 @@ object ColorUtils {
return String.format("#%06X", 0xFFFFFF and intColor)
}
fun stripAlpha(@ColorInt color: Int): Int {
return -0x1000000 or color
}
@ -176,72 +175,19 @@ object ColorUtils {
+ (colorByteArr[2].toInt() and 0xFF shl 8) + (colorByteArr[3].toInt() and 0xFF))
}
fun rgb2lab(R: Int, G: Int, B: Int): IntArray {
val x: Float
val y: Float
val z: Float
val fx: Float
val fy: Float
val fz: Float
val xr: Float
val yr: Float
val zr: Float
val eps = 216f / 24389f
val k = 24389f / 27f
val xr1 = 0.964221f // reference white D50
val yr1 = 1.0f
val zr1 = 0.825211f
// RGB to XYZ
var r: Float = R / 255f //R 0..1
var g: Float = G / 255f //G 0..1
var b: Float = B / 255f //B 0..1
// assuming sRGB (D65)
r = if (r <= 0.04045) r / 12 else ((r + 0.055) / 1.055).pow(2.4).toFloat()
g = if (g <= 0.04045) g / 12 else ((g + 0.055) / 1.055).pow(2.4).toFloat()
b = if (b <= 0.04045) b / 12 else ((b + 0.055) / 1.055).pow(2.4).toFloat()
x = 0.436052025f * r + 0.385081593f * g + 0.143087414f * b
y = 0.222491598f * r + 0.71688606f * g + 0.060621486f * b
z = 0.013929122f * r + 0.097097002f * g + 0.71418547f * b
// XYZ to Lab
xr = x / xr1
yr = y / yr1
zr = z / zr1
fx = if (xr > eps) xr.toDouble().pow(1 / 3.0)
.toFloat() else ((k * xr + 16.0) / 116.0).toFloat()
fy = if (yr > eps) yr.toDouble().pow(1 / 3.0)
.toFloat() else ((k * yr + 16.0) / 116.0).toFloat()
fz = if (zr > eps) zr.toDouble().pow(1 / 3.0)
.toFloat() else ((k * zr + 16.0) / 116).toFloat()
val ls: Float = 116 * fy - 16
val `as`: Float = 500 * (fx - fy)
val bs: Float = 200 * (fy - fz)
val lab = IntArray(3)
lab[0] = (2.55 * ls + .5).toInt()
lab[1] = (`as` + .5).toInt()
lab[2] = (bs + .5).toInt()
return lab
}
/**
* Computes the difference between two RGB colors by converting them to the L*a*b scale and
* comparing them using the CIE76 algorithm { http://en.wikipedia.org/wiki/Color_difference#CIE76}
*/
fun getColorDifference(a: Int, b: Int): Double {
val r1: Int = Color.red(a)
val g1: Int = Color.green(a)
val b1: Int = Color.blue(a)
val r2: Int = Color.red(b)
val g2: Int = Color.green(b)
val b2: Int = Color.blue(b)
val lab1 = rgb2lab(r1, g1, b1)
val lab2 = rgb2lab(r2, g2, b2)
val lab1 = DoubleArray(3)
val lab2 = DoubleArray(3)
ColorUtils.colorToLAB(a, lab1)
ColorUtils.colorToLAB(b, lab2)
return sqrt(
(lab2[0] - lab1[0].toDouble())
.pow(2.0) + (lab2[1] - lab1[1].toDouble())
.pow(2.0) + (lab2[2] - lab1[2].toDouble())
(lab2[0] - lab1[0])
.pow(2.0) + (lab2[1] - lab1[1])
.pow(2.0) + (lab2[2] - lab1[2])
.pow(2.0)
)
}