added load_specific_image_stack function

scripts/operations_tests/operations_tests.py

@@ -20,8 +20,6 @@
 import numpy as np
 import pandas as pd
 
-from mantidimaging.core.utility.data_containers import FILE_TYPES
-
 try:
     from plotly import graph_objs as go
     from plotly.subplots import make_subplots
@@ -34,6 +32,7 @@
 from mantidimaging.core.io.filenames import FilenameGroup  # noqa: E402
 from mantidimaging.core.io.loader import loader  # noqa: E402
 from mantidimaging.core.operations.loader import load_filter_packages  # noqa: E402
+from mantidimaging.core.utility.data_containers import FILE_TYPES  #
 
 script_dir = Path(__file__).resolve().parent
 log_directory = script_dir / "logs"
@@ -181,9 +180,23 @@ def add_nan(self, image_stack, fraction=0.001):
     def add_flats_and_darks(self, params):
         for frame_type in ['flat_before', 'dark_before', 'flat_after', 'dark_after']:
             if frame_type in params:
-                file_path = FilenameGroup.from_file(config_manager.load_sample)
-                file_path.find_related(getattr(FILE_TYPES, frame_type.upper()))
-                params[frame_type] = self.load_image_stack(file_path.get_path(getattr(FILE_TYPES, frame_type.upper())))
+                filename_group = FilenameGroup.from_file(config_manager.load_sample)
+                filename_group.find_all_files()
+                filename_group.find_related(getattr(FILE_TYPES, frame_type.upper()))
+
+                image_stack = self.load_specific_image_stack(filename_group, frame_type)
+                if image_stack is not None:
+                    params[frame_type] = image_stack
+                else:
+                    print(f"Failed to load image stack for {frame_type}")
+
+    def load_specific_image_stack(self, filename_group, frame_type):
+        try:
+            image_stack = loader.load(filename_group=filename_group)
+            return image_stack
+        except Exception as e:
+            print(f"Error loading image stack for {frame_type}: {e}")
+            return None
 
     def compare_mode(self):
         for operation, test_case_info in TEST_CASES.items():