Merge pull request #100 from ampas/feature/exclude_k_from_clf_export

Feature/exclude k from clf export

Author: KelSolaar

aces/idt/core/common.py

@@ -428,6 +428,7 @@ def clf_processing_elements(
     use_range: bool = True,
     include_white_balance_in_clf: bool = False,
     flatten_clf: bool = True,
+    include_exposure_factor_in_clf: bool = False,
 ) -> Et.Element:
     """
     Add the *Common LUT Format* (CLF) elements for given *IDT* matrix,
@@ -449,6 +450,8 @@ def clf_processing_elements(
         Whether to include the white balance multipliers in the *CLF*.
     flatten_clf
         Whether to flatten the *CLF*. into a single 1D Lut & 1 3x3 Matrix
+    include_exposure_factor_in_clf
+        Whether to include the exposure factor :math:`k` in the *CLF*.
 
     Returns
     -------
@@ -493,14 +496,15 @@ def format_array(a: NDArrayFloat) -> str:
             et_max_out_value = Et.SubElement(et_range, "maxOutValue")
             et_max_out_value.text = "1"
 
-        et_k = Et.SubElement(root, "Matrix", inBitDepth="32f", outBitDepth="32f")
-        et_description = Et.SubElement(et_k, "Description")
-        et_description.text = (
-            'Exposure factor *k* that results in a nominally "18% gray" object in '
-            "the scene producing ACES values [0.18, 0.18, 0.18]."
-        )
-        et_array = Et.SubElement(et_k, "Array", dim="3 3")
-        et_array.text = f"\n\t\t{format_array(np.ravel(np.diag([k_factor] * 3)))}"
+        if include_exposure_factor_in_clf:
+            et_k = Et.SubElement(root, "Matrix", inBitDepth="32f", outBitDepth="32f")
+            et_description = Et.SubElement(et_k, "Description")
+            et_description.text = (
+                'Exposure factor *k* that results in a nominally "18% gray" object in '
+                "the scene producing ACES values [0.18, 0.18, 0.18]."
+            )
+            et_array = Et.SubElement(et_k, "Array", dim="3 3")
+            et_array.text = f"\n\t\t{format_array(np.ravel(np.diag([k_factor] * 3)))}"
 
         et_M = Et.SubElement(root, "Matrix", inBitDepth="32f", outBitDepth="32f")
         et_description = Et.SubElement(et_M, "Description")
@@ -510,6 +514,11 @@ def format_array(a: NDArrayFloat) -> str:
 
     else:
         # If we are flattening the clf we output just a single matrix into the clf
+
+        # If we do not include the k factor, we set it to 1.0 so it becomes and identity
+        # matrix and has no affect
+        if not include_exposure_factor_in_clf:
+            k_factor = 1.0
         output_matrix = np.diag([k_factor] * 3) @ matrix
         if include_white_balance_in_clf:
             output_matrix = np.diag(multipliers) @ np.diag([k_factor] * 3) @ matrix

aces/idt/core/constants.py

@@ -460,6 +460,15 @@ class ProjectSettingsMetadataConstants:
         ui_category=UICategories.STANDARD,
     )
 
+    INCLUDE_EXPOSURE_FACTOR_IN_CLF = Metadata(
+        name="include_exposure_factor_in_clf",
+        default_value=False,
+        description="Whether to include the exposure factor (K) in the CLF",
+        display_name="Include Exposure Factor in CLF",
+        ui_type=UITypes.BOOLEAN_FIELD,
+        ui_category=UICategories.STANDARD,
+    )
+
     ALL: ClassVar[tuple[Metadata, ...]] = (
         SCHEMA_VERSION,
         CAMERA_MAKE,
@@ -493,4 +502,5 @@ class ProjectSettingsMetadataConstants:
         OPTIMIZATION_KWARGS,
         INCLUDE_WHITE_BALANCE_IN_CLF,
         FLATTEN_CLF,
+        INCLUDE_EXPOSURE_FACTOR_IN_CLF,
     )

aces/idt/framework/project_settings.py

@@ -181,6 +181,10 @@ def __init__(self, **kwargs: Dict):
             IDTProjectSettings.flatten_clf.metadata.name,
             IDTProjectSettings.flatten_clf.metadata.default_value,
         )
+        self._include_exposure_factor_in_clf = kwargs.get(
+            IDTProjectSettings.include_exposure_factor_in_clf.metadata.name,
+            IDTProjectSettings.include_exposure_factor_in_clf.metadata.default_value,
+        )
 
     @metadata_property(metadata=MetadataConstants.SCHEMA_VERSION)
     def schema_version(self) -> str:
@@ -598,6 +602,18 @@ def flatten_clf(self) -> str:
 
         return self._flatten_clf
 
+    @metadata_property(metadata=MetadataConstants.INCLUDE_EXPOSURE_FACTOR_IN_CLF)
+    def include_exposure_factor_in_clf(self) -> bool:
+        """
+        Getter property for whether to include the exposure factor (K) in the *CLF*.
+
+        Returns
+        -------
+        :class:`bool`
+            Whether to include the exposure factor (K) in the *CLF*.
+        """
+        return self._include_exposure_factor_in_clf
+
     def get_reference_colour_checker_samples(self) -> NDArrayFloat:
         """
         Return the reference colour checker samples.

aces/idt/generators/base_generator.py

@@ -837,6 +837,7 @@ def format_array(a):
             False,
             self.project_settings.include_white_balance_in_clf,
             self.project_settings.flatten_clf,
+            self.project_settings.include_exposure_factor_in_clf,
         )
 
         clf_path = (

tests/resources/example_from_folder.json

@@ -6,6 +6,7 @@
     "camera_make": "",
     "camera_model": "",
     "include_white_balance_in_clf": false,
+    "include_exposure_factor_in_clf": false,
     "flatten_clf": false,
     "iso": 800,
     "temperature": 6000,