Merge pull request #733 from roboflow/fix/speed-estimation-issue-when-detections-empty

`fix/speed-estimation-issue-when-detections-empty`

examples/speed_estimation/requirements.txt

@@ -1,6 +1,6 @@
 supervision==0.18.0rc1
-tqdm
+tqdm==4.66.1
 requests
-ultralytics
-super-gradients
-inference
+ultralytics==8.0.237
+super-gradients==3.5.0
+inference==0.9.8

examples/speed_estimation/ultralytics_example.py

@@ -29,6 +29,9 @@ class ViewTransformer:
         self.m = cv2.getPerspectiveTransform(source, target)
 
     def transform_points(self, points: np.ndarray) -> np.ndarray:
+        if points.size == 0:
+            return points
+
         reshaped_points = points.reshape(-1, 1, 2).astype(np.float32)
         transformed_points = cv2.perspectiveTransform(reshaped_points, self.m)
         return transformed_points.reshape(-1, 2)