Adds Apple Log 2 and Linear Apple Wide Gamut

docs/opencolorio_config_aces.clf.rst

@@ -39,6 +39,7 @@ Common LUT Format Generation
 .. autosummary::
     :toctree: generated/
 
+    generate_clf_transforms_apple
     generate_clf_transforms_arri
     generate_clf_transforms_bmdfilm
     generate_clf_transforms_canon

opencolorio_config_aces/clf/__init__.py

@@ -10,6 +10,7 @@
 )
 from .transforms import (
     generate_clf_transform,
+    generate_clf_transforms_apple,
     generate_clf_transforms_arri,
     generate_clf_transforms_bmdfilm,
     generate_clf_transforms_canon,
@@ -32,6 +33,7 @@
 __all__ += [
     "generate_clf_transform",
     "generate_clf_transform",
+    "generate_clf_transforms_apple",
     "generate_clf_transforms_arri",
     "generate_clf_transforms_bmdfilm",
     "generate_clf_transforms_canon",

opencolorio_config_aces/clf/discover/classify.py

@@ -1051,7 +1051,7 @@ def discover_clf_transforms(
     'input'
     >>> sorted([os.path.basename(path) for path in clf_transforms[key]])[:2]
     ['Apple.Input.Apple_Log-Curve.clf', \
-'Apple.Input.Apple_Log_to_ACES2065-1.clf']
+'Apple.Input.Apple_Log_2_to_ACES2065-1.clf']
     """
 
     root_directory = os.path.normpath(os.path.expandvars(root_directory))
@@ -1114,9 +1114,9 @@ def classify_clf_transforms(
     [('Apple.Input.Apple_Log-Curve', \
 CLFTransform(\
 'apple...input...Apple.Input.Apple_Log-Curve.clf')), \
-('Apple.Input.Apple_Log_to_ACES2065-1', \
+('Apple.Input.Apple_Log_2_to_ACES2065-1', \
 CLFTransform(\
-'apple...input...Apple.Input.Apple_Log_to_ACES2065-1.clf'))]
+'apple...input...Apple.Input.Apple_Log_2_to_ACES2065-1.clf'))]
     """
 
     classified_clf_transforms = defaultdict(lambda: defaultdict(dict))

opencolorio_config_aces/clf/transforms/__init__.py

@@ -9,6 +9,9 @@
     format_clf_transform_id,
     clf_basename,
 )
+from .apple import (
+    generate_clf_transforms_apple,
+)
 from .arri import (
     generate_clf_transforms_arri,
 )
@@ -46,6 +49,9 @@
     "format_clf_transform_id",
     "clf_basename",
 ]
+__all__ += [
+    "generate_clf_transforms_apple",
+]
 __all__ += [
     "generate_clf_transforms_arri",
 ]

opencolorio_config_aces/clf/transforms/apple/generate.py

@@ -14,13 +14,16 @@
 
 from pathlib import Path
 
+import numpy as np
 import PyOpenColorIO as ocio
 
 from opencolorio_config_aces.clf.transforms import (
     clf_basename,
     format_clf_transform_id,
     generate_clf_transform,
+    matrix_transform,
 )
+from opencolorio_config_aces.utilities import required
 
 __author__ = "OpenColorIO Contributors"
 __copyright__ = "Copyright Contributors to the OpenColorIO Project."
@@ -52,11 +55,51 @@
 """
 
 
+@required("Colour")
+def _build_apple_wg_mtx() -> ocio.MatrixTransform:
+    """
+    Build the `MatrixTransform` for the *Apple Wide Gamut* primaries.
+
+    The *Apple Log 2* white paper publishes neither the matrix nor the
+    chromatic adaptation transform to use, thus the matrix is derived from the
+    primaries using *Bradford* adaptation, as it is the most consistent with
+    *ACES* and matches the *OpenColorIO* `APPLE_LOG-APPLEWG_to_ACES2065-1`
+    builtin transform.
+
+    Returns
+    -------
+    :class:`ocio.MatrixTransform`
+         *OpenColorIO* `MatrixTransform`.
+    """
+
+    import colour
+
+    # Primaries as defined in: "Apple Log 2 Profile".
+    colourspace = colour.RGB_Colourspace(
+        "Apple Wide Gamut",
+        np.array([[0.725, 0.301], [0.221, 0.814], [0.068, -0.076]]),
+        np.array([0.3127, 0.3290]),
+    )
+    colourspace.use_derived_transformation_matrices(True)
+
+    colourspace_ACES2065_1 = colour.RGB_COLOURSPACES["ACES2065-1"]
+    colourspace_ACES2065_1.use_derived_transformation_matrices(True)
+
+    return matrix_transform(
+        colour.matrix_RGB_to_RGB(
+            colourspace,
+            colourspace_ACES2065_1,
+            chromatic_adaptation_transform="Bradford",
+        )
+    )
+
+
 def generate_clf_transforms_apple(
     output_directory: Path,
 ) -> dict[Path, ocio.GroupTransform]:
     """
-    Generate the *CLF* transforms for *Apple Log* and for *Apple Log* curve.
+    Generate the *CLF* transforms for *Apple Log*, *Apple Log 2* and for the
+    *Apple Log* curve.
 
     Parameters
     ----------
@@ -74,6 +117,9 @@ def generate_clf_transforms_apple(
     -   Apple. (September 22, 2023). Apple Log Profile.
         Retrieved February 2, 2024, from
         https://developer.apple.com/download/all/?q=Apple%20log%20profile
+    -   Apple. (2025). Apple Log 2 Profile.
+        Retrieved from
+        https://developer.apple.com/download/all/?q=Apple%20log%20profile
 
     Notes
     -----
@@ -105,6 +151,46 @@ def generate_clf_transforms_apple(
         style=style,
     )
 
+    # "Apple Log 2" uses the same transfer function as "Apple Log" but encodes
+    # in the "Apple Wide Gamut" primaries rather than "ITU-R BT.2020".
+
+    aces_transform_id = (
+        "urn:ampas:aces:transformId:v2.0:CSC.Apple.AppleLog2_to_ACES.a2.v1"
+    )
+
+    name = "Apple_Log_2_to_ACES2065-1"
+    input_descriptor = "Apple Log 2"
+    output_descriptor = "ACES2065-1"
+    clf_transform_id = format_clf_transform_id(FAMILY, GENUS, name, VERSION)
+    filename = output_directory / clf_basename(clf_transform_id)
+    style = "APPLE_LOG-APPLEWG_to_ACES2065-1"
+    clf_transforms[filename] = generate_clf_transform(
+        filename,
+        [{"transform_type": "BuiltinTransform", "style": style}],
+        clf_transform_id,
+        f"{input_descriptor} to {output_descriptor}",
+        input_descriptor,
+        output_descriptor,
+        aces_transform_id=aces_transform_id,
+        style=style,
+    )
+
+    # Generate transform for primaries only.
+
+    name = "Linear_Apple_Wide_Gamut_to_ACES2065-1"
+    input_descriptor = "Linear Apple Wide Gamut"
+    output_descriptor = "ACES2065-1"
+    clf_transform_id = format_clf_transform_id(FAMILY, GENUS, name, VERSION)
+    filename = output_directory / clf_basename(clf_transform_id)
+    clf_transforms[filename] = generate_clf_transform(
+        filename,
+        [_build_apple_wg_mtx()],
+        clf_transform_id,
+        f"{input_descriptor} to {output_descriptor}",
+        input_descriptor,
+        output_descriptor,
+    )
+
     # Generate `NamedTransform` for log curve only.
 
     name = "Apple_Log-Curve_to_Linear"