diff --git a/src/eynollah/eynollah.py b/src/eynollah/eynollah.py
index 27277ee..9071f7a 100644
--- a/src/eynollah/eynollah.py
+++ b/src/eynollah/eynollah.py
@@ -107,6 +107,7 @@ from .utils.drop_capitals import (
 from .utils.marginals import get_marginals
 from .utils.resize import resize_image
 from .utils import (
+    is_image_filename,
     boosting_headers_by_longshot_region_segmentation,
     crop_image_inside_box,
     find_num_col,
@@ -4547,14 +4548,13 @@ class Eynollah:
             self.logger.info("Enabled modes: " + ", ".join(enabled_modes))
 
         if dir_in:
-            self.ls_imgs  = os.listdir(dir_in)
-            self.ls_imgs = [ind_img for ind_img in self.ls_imgs if ind_img.endswith('.jpg') or ind_img.endswith('.jpeg') or ind_img.endswith('.png') or ind_img.endswith('.tif') or ind_img.endswith('.tiff') or ind_img.endswith('.JPG') or ind_img.endswith('.JPEG') or ind_img.endswith('.TIF') or ind_img.endswith('.TIFF') or ind_img.endswith('.PNG')]
+            ls_imgs = list(filter(is_image_filename, os.listdir(self.dir_in)))
         elif image_filename:
-            self.ls_imgs = [image_filename]
+            ls_imgs = [image_filename]
         else:
             raise ValueError("run requires either a single image filename or a directory")
 
-        for img_filename in self.ls_imgs:
+        for img_filename in ls_imgs:
             self.logger.info(img_filename)
             t0 = time.time()
 
@@ -5394,8 +5394,7 @@ class Eynollah_ocr:
 
     def run(self, overwrite : bool = False):
         if self.dir_in:
-            ls_imgs = os.listdir(self.dir_in)
-            ls_imgs = [ind_img for ind_img in ls_imgs if ind_img.endswith('.jpg') or ind_img.endswith('.jpeg') or ind_img.endswith('.png') or ind_img.endswith('.tif') or ind_img.endswith('.tiff') or ind_img.endswith('.JPG') or ind_img.endswith('.JPEG') or ind_img.endswith('.TIF') or ind_img.endswith('.TIFF') or ind_img.endswith('.PNG')]
+            ls_imgs = list(filter(is_image_filename, os.listdir(self.dir_in)))
         else:
             ls_imgs = [self.image_filename]
         
diff --git a/src/eynollah/image_enhancer.py b/src/eynollah/image_enhancer.py
index f577e52..5a06d59 100644
--- a/src/eynollah/image_enhancer.py
+++ b/src/eynollah/image_enhancer.py
@@ -21,6 +21,7 @@ from tensorflow.keras.models import load_model
 from .utils.resize import resize_image
 from .utils.pil_cv2 import pil2cv
 from .utils import (
+    is_image_filename,
     crop_image_inside_box
 )
 
@@ -701,13 +702,13 @@ class Enhancer:
         t0_tot = time.time()
 
         if dir_in:
-            self.ls_imgs  = os.listdir(dir_in)
+            ls_imgs = list(filter(is_image_filename, os.listdir(dir_in)))
         elif image_filename:
-            self.ls_imgs = [image_filename]
+            ls_imgs = [image_filename]
         else:
             raise ValueError("run requires either a single image filename or a directory")
 
-        for img_filename in self.ls_imgs:
+        for img_filename in ls_imgs:
             self.logger.info(img_filename)
             t0 = time.time()
 
diff --git a/src/eynollah/sbb_binarize.py b/src/eynollah/sbb_binarize.py
index 2d5035f..3716987 100644
--- a/src/eynollah/sbb_binarize.py
+++ b/src/eynollah/sbb_binarize.py
@@ -16,6 +16,7 @@ import tensorflow as tf
 from tensorflow.keras.models import load_model
 from tensorflow.python.keras import backend as tensorflow_backend
 
+from .utils import is_image_filename
 
 def resize_image(img_in, input_height, input_width):
     return cv2.resize(img_in, (input_width, input_height), interpolation=cv2.INTER_NEAREST)
@@ -347,7 +348,7 @@ class SbbBinarizer:
                 cv2.imwrite(output, img_last)
             return img_last
         else:
-            ls_imgs  = os.listdir(dir_in)
+            ls_imgs = list(filter(is_image_filename, os.listdir(dir_in)))
             for image_name in ls_imgs:
                 image_stem = image_name.split('.')[0]
                 print(image_name,'image_name')
diff --git a/src/eynollah/utils/__init__.py b/src/eynollah/utils/__init__.py
index ca86047..c154fe4 100644
--- a/src/eynollah/utils/__init__.py
+++ b/src/eynollah/utils/__init__.py
@@ -2194,3 +2194,11 @@ def return_boxes_of_images_by_order_of_reading_new(
         return boxes, peaks_neg_tot_tables_new
     else:
         return boxes, peaks_neg_tot_tables
+
+def is_image_filename(fname: str) -> bool:
+    return fname.lower().endswith(('.jpg',
+                                   '.jpeg',
+                                   '.png',
+                                   '.tif',
+                                   '.tiff',
+    ))