Added padding to enable border detection at image boundaries

colorbynumber/gen_islands.py

@@ -10,9 +10,11 @@ class GenerateIslands:
         self.gradient_kernel = np.ones((gradient_kernel_size, gradient_kernel_size), np.uint8)
         self.color_index_island_list = []
     
-    def _get_islands_for_one_color(self, color_index):
+    def _get_islands_for_one_color(self, color_index, border_padding):
         # Get a binary image with just the selected color
         this_color = (self.indices_color_choices == color_index).astype(np.uint8)
+        # Pad the image to enable border detection on image boundaries
+        this_color = np.pad(this_color, border_padding, mode='constant', constant_values=0)
 
         # Find connected components
         num_labels, labels_im = cv.connectedComponents(this_color)
@@ -29,9 +31,9 @@ class GenerateIslands:
         
         return this_color_index_island_list
     
-    def get_islands(self):
+    def get_islands(self, border_padding=2):
         for color_index in np.unique(self.indices_color_choices):
-            this_color_index_island_list = self._get_islands_for_one_color(color_index)
+            this_color_index_island_list = self._get_islands_for_one_color(color_index, border_padding)
             self.color_index_island_list.extend(this_color_index_island_list)
         
         return self.color_index_island_list

colorbynumber/numbered_islands.py

@@ -34,7 +34,7 @@ def _add_text_to_image(image, text, position, font_size=1, font_color=(0, 0, 0))
         )
 
 
-def create_numbered_islands(islands, image_shape, border_color=[0, 0, 0]):
+def create_numbered_islands(islands, image_shape, border_color=[0, 0, 0], padding=2):
     """Create a new image with the islands numbered.
     
     Args:
@@ -45,7 +45,9 @@ def create_numbered_islands(islands, image_shape, border_color=[0, 0, 0]):
         np.array: A new image with the islands numbered.
     """
     # Create an all white image
-    numbered_islands = np.ones(image_shape, dtype=np.uint8) * 255
+    width, height, channels = image_shape
+    numbered_islands = np.ones((width + padding*2, height + padding*2, channels), 
+                               dtype=np.uint8) * 255
 
     for color_id, island_coordinates in islands:
         numbered_islands[island_coordinates] = border_color