invert output image

app.py

@@ -16,7 +16,8 @@ def detect_edges(image:str, sigma, upper_thresh, lower_thresh)->np.ndarray:
         low_threshold=lower_thresh,
         high_threshold=upper_thresh,
     )
-    return edges*255
+    inverted_image = cv2.bitwise_not(edges)
+    return inverted_image*255
 
 edge_detector_interface = gr.Interface(
     fn=detect_edges,
@@ -29,4 +30,4 @@ edge_detector_interface = gr.Interface(
     outputs=[gr.Image(label="Edge Detected Image", image_mode="L", height=400)]
 )
 
-edge_detector_interface.launch()
+edge_detector_interface.launch()