diff --git a/Question_11_20/answers_py/answer_17.py b/Question_11_20/answers_py/answer_17.py
index c3064c89..8f641dc8 100644
--- a/Question_11_20/answers_py/answer_17.py
+++ b/Question_11_20/answers_py/answer_17.py
@@ -16,7 +16,11 @@ def BGR2GRAY(img):
 
 # laplacian filter
 def laplacian_filter(img, K_size=3):
-	H, W, C = img.shape
+	if len(img.shape) == 3:
+		H, W, C = img.shape
+	else:
+		img = np.expand_dims(img, axis=-1)
+		H, W, C = img.shape
 
 	# zero padding
 	pad = K_size // 2