diff --git a/tests/test_diff_motion_detector/test.py b/tests/test_diff_motion_detector/test.py
index e468af8..86573e9 100644
--- a/tests/test_diff_motion_detector/test.py
+++ b/tests/test_diff_motion_detector/test.py
@@ -13,3 +13,41 @@ def test_set_background_successfully(self):
         background_image = cv2.imread('background.jpg')
         detector.setBackground(background_image)
         assert detector.getBackground() is not None
+
+    # Tests that a binary image is returned successfully after the detection process
+    def test_return_binary_image_successfully(self):
+        detector = DiffMotionDetector()
+        background_image = cv2.imread('background.jpg')
+        foreground_image = cv2.imread('foreground.jpg')
+        detector.setBackground(background_image)
+        binary_image = detector.returnMask(foreground_image)
+        assert binary_image is not None
+
+    # Tests that a background image is set and a binary image is returned successfully after the detection process
+    def test_set_background_and_return_binary_image_successfully(self):
+        detector = DiffMotionDetector()
+        background_image = cv2.imread('background.jpg')
+        foreground_image = cv2.imread('foreground.jpg')
+        detector.setBackground(background_image)
+        binary_image = detector.returnMask(foreground_image)
+        assert detector.getBackground() is not None and binary_image is not None
+
+    # Tests that setting a None background image returns None
+    def test_set_none_background_image_and_return_none(self):
+        detector = DiffMotionDetector()
+        detector.setBackground(None)
+        assert detector.getBackground() is None
+
+    # Tests that setting a None foreground image returns None
+    def test_set_none_foreground_image_and_return_none(self):
+        detector = DiffMotionDetector()
+        background_image = cv2.imread('background.jpg')
+        detector.setBackground(background_image)
+        binary_image = detector.returnMask(None)
+        assert binary_image is None
+
+    # Tests that setting a None background image returns None after the detection process
+    def test_set_none_background_image_and_return_none_after_detection_process(self):
+        detector = DiffMotionDetector()
+        detector.setBackground(None)
+        assert detector.getBackground() is None