From 8b2dee847ce085a142fb03afef79ffcc9cee821a Mon Sep 17 00:00:00 2001
From: kunfei <gekunfei@live.com>
Date: Sat, 14 May 2022 18:29:20 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BC=98=E5=8C=96?=
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---
 .../java/io/legado/app/utils/ColorUtils.kt    | 68 ++-----------------
 1 file changed, 7 insertions(+), 61 deletions(-)

diff --git a/app/src/main/java/io/legado/app/utils/ColorUtils.kt b/app/src/main/java/io/legado/app/utils/ColorUtils.kt
index 03280a852..6ac8eccd1 100644
--- a/app/src/main/java/io/legado/app/utils/ColorUtils.kt
+++ b/app/src/main/java/io/legado/app/utils/ColorUtils.kt
@@ -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)
         )
     }