Fixing grayscale conversion

src/gui/tabs/training_tab.py

@@ -34,6 +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 convert_grayscale_to_rgb_preserve_range
 from src.utils.logger import get_logger
 
 
@@ -1361,7 +1362,10 @@ class TrainingTab(QWidget):
             dst.parent.mkdir(parents=True, exist_ok=True)
             try:
                 with PILImage.open(src) as img:
-                    rgb_img = img.convert("RGB")
+                    if len(img.getbands()) == 1:
+                        rgb_img = convert_grayscale_to_rgb_preserve_range(img)
+                    else:
+                        rgb_img = img.convert("RGB")
                     rgb_img.save(dst)
             except Exception as exc:
                 logger.warning(f"Failed to convert {src} to RGB: {exc}")