Update app.py

app.py

@@ -28,8 +28,8 @@ vehicle_threshold = 0.5
 def bbox_normalization(bbox, width, height):
     height_coeff = height/352
     width_coeff = width/352
-    normalized_bbox = [bbox[0]*width_coeff, bbox[1]*height_coeff,
-                       bbox[2]*width_coeff, bbox[3]*height_coeff]
+    normalized_bbox = [[bbox[0]*width_coeff, bbox[1]*height_coeff],
+                       [bbox[2]*width_coeff, bbox[3]*height_coeff]]
     return normalized_bbox
 
 def bbox_area(bbox):