diff --git a/src/twomartens/masterthesis/debug.py b/src/twomartens/masterthesis/debug.py
index 2afd67f..ae5a2da 100644
--- a/src/twomartens/masterthesis/debug.py
+++ b/src/twomartens/masterthesis/debug.py
@@ -33,7 +33,7 @@ from twomartens.masterthesis import config
 from twomartens.masterthesis.ssd_keras.eval_utils import coco_utils
 
 
-def save_ssd_train_images(images: np.ndarray, labels: np.ndarray, output_path: str) -> None:
+def save_ssd_train_images(images: np.ndarray, labels: np.ndarray, output_path: str, custom_string: str = None) -> None:
     annotation_file_train = f"{config.get_property('Paths.coco')}/annotations/instances_train2014.json"
     _, _, _, classes_to_names = coco_utils.get_coco_category_maps(annotation_file_train)
     colors = pyplot.cm.hsv(np.linspace(0, 1, 81)).tolist()
@@ -42,12 +42,13 @@ def save_ssd_train_images(images: np.ndarray, labels: np.ndarray, output_path: s
     nr_images = len(images)
     nr_digits = math.ceil(math.log10(nr_images))
     image_size = config.get_property("Parameters.ssd_image_size")
+    custom_string = f"{custom_string}_" if custom_string is not None else ""
     
     for i, train_image in enumerate(images):
         instances = labels[i]
         image = Image.fromarray(train_image)
         image.save(f"{output_path}/"
-                   f"train_image{str(i).zfill(nr_digits)}.png")
+                   f"{custom_string}train_image{str(i).zfill(nr_digits)}.png")
         
         figure = pyplot.figure(figsize=(20, 12))
         pyplot.imshow(image)