src/Transformer/Utilities/CyanMagentaYellowKeyToHueSaturationValue.php

@@ -74,7 +74,9 @@ class CyanMagentaYellowKeyToHueSaturationValue
 
     protected function buildHueAmount(): float
     {
-        if ($this->maxCmyProperty === 0.0) {
+        // Wenn beide Werte gleich sind, ist die Endfarbe Grau.
+        // Damit wird auch in {@sse hueAmount()} eine Division durch Null verhindert.
+        if ($this->maxCmyProperty === $this->minCmyProperty) {
             return 0.0;
         }
 
@@ -91,30 +93,32 @@ class CyanMagentaYellowKeyToHueSaturationValue
      */
     private function hueAmount(string $property): float
     {
-        static $amount_share = 2.0;
-
+        // Wertebereich: [0.0, 1.0]
         $divisor = $this->maxCmyProperty - $this->minCmyProperty;
+        // Wertebereich: [1.0, 5.0]
+        $amount = 0.0;
+        // Wertebereich: [-1.0, +1.0]
+        $dividend = 0.0;
 
         switch ($property) {
             case self::PROPERTY_YELLOW:
-                $amount = 0; // 0.167
+                $amount = 1.0; // 0.167
                 $dividend = $this->cyan - $this->magenta;
                 break;
             case self::PROPERTY_CYAN:
-                $amount = 1; // 0.500
+                $amount = 3.0; // 0.500
                 $dividend = $this->magenta -$this->yellow;
                 break;
             case self::PROPERTY_MAGENTA:
-                $amount = 2; // 0.833
+                $amount = 5.0; // 0.833
                 $dividend = $this->yellow - $this->cyan;
                 break;
-            default:
-                return 0;
         }
 
-        $start_amount = ($amount * $amount_share) + 1.0;
+        // Wertebereich: [-1.0, +1.0]
         $expansion_amount = $dividend / $divisor;
-        return ($start_amount + $expansion_amount) / 6.0;
+        // Wertebereich: [+0.0, +6.0]
+        return ($amount + $expansion_amount) / 6.0;
     }
 
 }

src/Transformer/Utilities/RedGreenBlueToHueSaturationValue.php

@@ -58,10 +58,6 @@ class RedGreenBlueToHueSaturationValue
         while($this->hue < 0.0) {
             $this->hue += 1.0;
         }
-
-        while($this->hue > 1.0) {
-            $this->hue -= 1.0;
-        }
     }
 
     public function convert(): HueSaturationValue
@@ -76,6 +72,8 @@ class RedGreenBlueToHueSaturationValue
 
     protected function buildHueAmount(): float
     {
+        // Wenn beide Werte gleich sind, ist die Endfarbe Grau.
+        // Damit wird auch in {@sse hueAmount()} eine Division durch Null verhindert.
         if ($this->maxRgbProperty === $this->minRgbProperty) {
             return 0.0;
         }
@@ -105,30 +103,32 @@ class RedGreenBlueToHueSaturationValue
      */
     private function hueAmount(string $property): float
     {
-        static $amount_share = 2.0;
-
+        // Wertebereich: [0.0, 1.0]
         $divisor = $this->maxRgbProperty - $this->minRgbProperty;
+        // Wertebereich: [1.0, 5.0]
+        $amount = 0.0;
+        // Wertebereich: [-1.0, +1.0]
+        $dividend = 0.0;
 
         switch ($property) {
             case self::PROPERTY_RED:
-                $amount = 0; // 0.0
+                $amount = 0.0; // 0.0
                 $dividend = $this->green - $this->blu;
                 break;
             case self::PROPERTY_GREEN:
-                $amount = 1; // 0.333
+                $amount = 2.0; // 0.333
                 $dividend = $this->blu -$this->red;
                 break;
             case self::PROPERTY_BLUE:
-                $amount = 2; // 0.999
+                $amount = 4.0; // 0.999
                 $dividend = $this->red - $this->green;
                 break;
-            default:
-                return 0;
         }
 
-        $start_amount = $amount * $amount_share;
+        // Wertebereich: [-1.0, +1.0]
         $expansion_amount = $dividend / $divisor;
-        return ($start_amount + $expansion_amount) / 6.0;
+        // Wertebereich: [-1.0, +5.0]
+        return ($amount + $expansion_amount) / 6.0;
     }
 
 }