Find nearest color

gamebeye/gbcamcolors/color_helpers.py

@@ -2,6 +2,7 @@
 
 import numpy as np
 import numpy.typing as npt
+import skimage.color
 
 
 def clamp(val: int) -> int:
@@ -336,3 +337,43 @@ def bgr_to_rgb(bgr_val: npt.ArrayLike) -> np.ndarray:
     if not isinstance(bgr_val, tuple):
         bgr_val = tuple(clamp_rgb(bgr_val))
     return bgr_val[::-1]
+
+
+def scaled_array(
+    array: list, src_range: list[int], dest_range: list[int]
+) -> np.ndarray:
+    """
+    Scale an array from a source range to a destination range.
+
+    :param list array: array to scale
+
+    :returns: a scaled array
+    :rtype: np.ndarray
+
+    >>> from gamebeye.gbcamcolors.color_helpers import scaled_array
+    >>> scaled_array([0, 0, 255], [0, 255], [0, 1])
+    np.array([0., 0., 1.])
+    >>> scaled_array([512, 128, 0], [0, 255], [0, 1])
+    array([2.00784314, 0.50196078, 0. ])
+    """
+    array = np.array(array)
+    src_min, src_max = src_range
+    dest_min, dest_max = dest_range
+    return (array - src_min) / (src_max - src_min) * (dest_max - dest_min) + dest_min
+
+
+def rgb_to_lab(rgb_val):
+    """
+    Convert a (R, G, B) array to a (L, a, b) array.
+
+    :param list rgb_val: (R, G, B) list to convert
+
+    :returns: a list containing L, a, b values.
+    :rtype: np.array
+
+    >>> from gamebeye.gbcamcolors.color_helpers import rgb_to_lab
+    >>> rgb_to_lab([25, 50, 75])
+    array([ 20.0262693 ,  -0.6623394 , -18.32821659])
+    """
+    rgb_val = scaled_array(rgb_val, [0, 255], [0, 1])
+    return skimage.color.rgb2lab(rgb_val)

gamebeye/gbcamcolors/gbcolorvalues.py

@@ -3,7 +3,9 @@
 from enum import Enum, unique
 from typing import List, Tuple
 
-from gamebeye.gbcamcolors.color_helpers import hex_to_rgb
+from skimage.color import deltaE_ciede2000
+
+from gamebeye.gbcamcolors.color_helpers import hex_to_rgb, rgb_to_lab
 
 
 # Class decorator @unique ensure each enum value is unique
@@ -2332,7 +2334,28 @@ def rgb_colors(self) -> List[int]:
         :rtype: list[int]
 
         >>> from gamebeye.gbcamcolors.gbcolorvalues import GBColorValues
-        >>> GBcolorValues.ROYAL_NAVY_BLUE
+        >>> GBColorValues.ROYAL_NAVY_BLUE
         [1, 99, 198]
         """
         return hex_to_rgb(self.value)
+
+    @classmethod
+    def nearest_color(cls, rgb_value):
+        """
+        Find nearest color value among the GBColorValues.
+
+        :param list rgb_val: (R, G, B) list to convert
+
+        :return: the nearest color from the GBColorValues
+        :rtype: GBColorValue
+
+        >>> from gamebeye.gbcamcolors.gbcolorvalues import GBColorValues
+        >>> GBColorValues.nearest_color([2, 100, 198])
+        <GBColorValues.ROYAL_NAVY_BLUE: '#0163C6'>
+        """
+        ref_lab_color = rgb_to_lab(rgb_value)
+        distance = []
+        for color in cls:
+            lab_color = rgb_to_lab(color.rgb_colors)
+            distance.append((color, deltaE_ciede2000(ref_lab_color, lab_color)))
+        return min(distance, key=lambda d: d[1])[0]