add Gaussian Blur

app.py

@@ -93,7 +93,8 @@ def _preview_canny(
     """Fast Canny‑edge preview (already implemented)."""
 
     arr = np.array(pil_img.convert("RGB"))
-    edges = cv2.Canny(arr, threshold1=canny_threshold_1, threshold2=canny_threshold_2)
+    blurred = cv2.GaussianBlur(arr, (5, 5), 1.4)
+    edges = cv2.Canny(blurred, threshold1=canny_threshold_1, threshold2=canny_threshold_2)
     edges_rgb = cv2.cvtColor(edges, cv2.COLOR_GRAY2RGB)
     return Image.fromarray(edges_rgb)