I04_1-1014: add blank image when image is none

Author: UrszulaNeuman

dls_util/image/image.py

@@ -1,6 +1,7 @@
 import cv2 as opencv
 import math
 import numpy as np
+import logging
 
 from PyQt5 import QtCore
 from PyQt5.QtGui import QImage, QPixmap
@@ -13,6 +14,10 @@ class Image:
     """
     def __init__(self, img):
         self.img = img
+        if img is None:
+            log = logging.getLogger(".".join([__name__]))
+            log.info("image is none")
+            self.img = np.full((1, 1, 3), 0.0, np.uint8)
 
         size = self.img.shape
         self.width = size[1]
@@ -36,7 +41,13 @@ def is_valid(self):
     @staticmethod
     def from_file(filename):
         """ Return a new image by loading from the specified image file. """
-        img = opencv.imread(filename, opencv.IMREAD_UNCHANGED)
+        try:
+            img = opencv.imread(filename, opencv.IMREAD_UNCHANGED)
+        except:
+            log = logging.getLogger(".".join([__name__]))
+            log.info("check file path")
+            img = None
+            
         return Image(img)
 
     @staticmethod

tests/unit_tests/test_dls_util/test_image/test_image.py

@@ -232,4 +232,14 @@ def test_sub_image_is_created_if_the_center_is_outside_but_the_radius_ovelaps_wi
         self.assertEqual(width, 1)
         self.assertEqual(height, 1)
 
-    #def test_calculate_brightness
+    def test_empty_image_returned_when_image_is_none(self):
+        empty_image = Image(None)
+        self.assertEqual(empty_image.width, 1)
+        self.assertEqual(empty_image.height, 1)
+    
+    def test_from_file_returns_none_no_image_found_in_the_path(self):
+        wrong_file_path = "wrong_file.jpg"
+        img = Image.from_file(wrong_file_path)
+        
+        self.assertEqual(img.width, 1)
+