Add options for quantization

test/test_image_options.py

@@ -65,6 +65,33 @@ class Test_normalize_options(object):
             ("png_slow_optimization", 0, False),
             ("png_slow_optimization", "", False),
             ("png_slow_optimization", b"", False),
+            # enable_quantization
+            ("enable_quantization", True, True),
+            ("enable_quantization", False, False),
+            ("enable_quantization", 1, True),
+            ("enable_quantization", 0, False),
+            ("enable_quantization", "", False),
+            ("enable_quantization", b"", False),
+            # quantization_dithering_level
+            ("quantization_dithering_level", 0.42, 0.42),
+            ("quantization_dithering_level", 42, 1.0),
+            ("quantization_dithering_level", "0.42", 0.42),
+            ("quantization_dithering_level", ".42", 0.42),
+            ("quantization_dithering_level", "42", 1.0),
+            ("quantization_dithering_level", b"0.42", 0.42),
+            ("quantization_dithering_level", b".42", 0.42),
+            ("quantization_dithering_level", b"42", 1.0),
+            ("quantization_dithering_level", -1, 0.0),
+            # quantization_max_colors
+            ("quantization_max_colors", 128, 128),
+            ("quantization_max_colors", 128.5, 128),
+            ("quantization_max_colors", "128", 128),
+            ("quantization_max_colors", "128.5", 128),
+            ("quantization_max_colors", "255", 255),
+            ("quantization_max_colors", 300, 256),
+            ("quantization_max_colors", "300", 256),
+            ("quantization_max_colors", b"255", 255),
+            ("quantization_max_colors", 0, 1),
         ],
     )
     def test_options(self, option_name, input_, output):

yoga/image/options.py

@@ -3,12 +3,15 @@ import re
 
 # fmt: off
 DEFAULT_OPTIONS = {
-    "output_format": "orig",         # orig|auto|jpeg|png|webp|webpl
-    "resize": "orig",                # orig|[w,h]
-    "jpeg_quality": 0.84,            # 0.00-1.00
-    "webp_quality": 0.90,            # 0.00-1.00
-    "opacity_threshold": 254,        # 0-255
-    "png_slow_optimization": False,  # True|False
+    "output_format": "orig",              # orig|auto|jpeg|png|webp|webpl
+    "resize": "orig",                     # orig|[w,h]
+    "jpeg_quality": 0.84,                 # 0.00-1.00
+    "webp_quality": 0.90,                 # 0.00-1.00
+    "opacity_threshold": 254,             # 0-255
+    "png_slow_optimization": False,       # True|False
+    "enable_quantization": False,         # True|False
+    "quantization_dithering_level": 1.0,  # 0.00-1.00
+    "quantization_max_colors": 256,       # 1-256
 }
 # fmt: on
 
@@ -130,4 +133,39 @@ def normalize_options(options=None):
             options["png_slow_optimization"]
         )
 
+    # "" -> False
+    # 0 -> False
+    # 1 -> True
+    if "enable_quantization" in options:
+        result["enable_quantization"] = bool(options["enable_quantization"])
+
+    # > 1.0 -> 1.0
+    # < 0.0 -> 0.0
+    # "0.5" -> 0.5
+    if "quantization_dithering_level" in options:
+        value = options["quantization_dithering_level"]
+
+        if type(value) in (str, bytes):
+            value = float(value)
+
+        value = max(value, 0.0)
+        value = min(value, 1.0)
+
+        result["quantization_dithering_level"] = value
+
+    # > 256 -> 256
+    # < 1 -> 1
+    # "128" -> 128
+    # 128.5 -> 128
+    if "quantization_max_colors" in options:
+        value = options["quantization_max_colors"]
+
+        if type(value) in (str, bytes):
+            value = float(value)
+
+        value = max(value, 1)
+        value = min(value, 256)
+
+        result["quantization_max_colors"] = int(value)
+
     return result