Merge pull request #1049 from rolson24/fix-pr-bug

fix enumerate call

supervision/tracker/byte_tracker/core.py

@@ -272,11 +272,8 @@ def callback(frame: np.ndarray, index: int) -> np.ndarray:
         """
 
         tensors = detections2boxes(detections=detections)
-
         tracks = self.update_with_tensors(tensors=tensors)
 
-        final_detections = Detections.empty()
-
         if len(tracks) > 0:
             detection_bounding_boxes = np.asarray([det[:4] for det in tensors])
             track_bounding_boxes = np.asarray([track.tlbr for track in tracks])
@@ -286,20 +283,16 @@ def callback(frame: np.ndarray, index: int) -> np.ndarray:
             iou_costs = 1 - ious
 
             matches, _, _ = matching.linear_assignment(iou_costs, 0.5)
-            for i, idet, itrack in enumerate(matches):
-                if i == 0:
-                    final_detections = detections[[idet]]
-                    final_detections.tracker_id[0] = int(tracks[itrack].track_id)
-                else:
-                    current_detection = detections[[idet]]
-                    current_detection.tracker_id[0] = int(tracks[itrack].track_id)
-                    final_detections = Detections.merge(
-                        [final_detections, current_detection]
-                    )
+            detections.tracker_id = np.full(len(detections), -1, dtype=int)
+            for i_detection, i_track in matches:
+                detections.tracker_id[i_detection] = int(tracks[i_track].track_id)
+
+            return detections[detections.tracker_id != -1]
+
         else:
-            final_detections.tracker_id = np.array([], dtype=int)
+            detections.tracker_id = np.array([], dtype=int)
 
-        return final_detections
+            return detections
 
     def reset(self):
         """