Update on convert_grayscale_to_rgb_preserve_range, making it class method

src/gui/tabs/training_tab.py

@@ -34,7 +34,7 @@ from PySide6.QtWidgets import (
 from src.database.db_manager import DatabaseManager
 from src.model.yolo_wrapper import YOLOWrapper
 from src.utils.config_manager import ConfigManager
-from src.utils.image import Image, convert_grayscale_to_rgb_preserve_range
+from src.utils.image import Image
 from src.utils.logger import get_logger
 
 
@@ -1368,7 +1368,7 @@ class TrainingTab(QWidget):
                 img_obj = Image(src)
                 pil_img = img_obj.pil_image
                 if len(pil_img.getbands()) == 1:
-                    rgb_img = convert_grayscale_to_rgb_preserve_range(pil_img)
+                    rgb_img = img_obj.convert_grayscale_to_rgb_preserve_range()
                 else:
                     rgb_img = pil_img.convert("RGB")
                 rgb_img.save(dst)