Integrate ByteTracker and BoT-SORT trackers (#788)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>
Co-authored-by: Ayush Chaurasia <ayush.chaurarsia@gmail.com>

ultralytics/yolo/engine/results.py

@@ -44,6 +44,14 @@ class Results:
             setattr(r, item, getattr(self, item)[idx])
         return r
 
+    def update(self, boxes=None, masks=None, probs=None):
+        if boxes is not None:
+            self.boxes = Boxes(boxes, self.orig_shape)
+        if masks is not None:
+            self.masks = Masks(masks, self.orig_shape)
+        if boxes is not None:
+            self.probs = probs
+
     def cpu(self):
         r = Results(orig_shape=self.orig_shape)
         for item in self.comp:
@@ -138,7 +146,10 @@ class Boxes:
     def __init__(self, boxes, orig_shape) -> None:
         if boxes.ndim == 1:
             boxes = boxes[None, :]
-        assert boxes.shape[-1] == 6  # xyxy, conf, cls
+        n = boxes.shape[-1]
+        assert n in {6, 7}, f"expected `n` in [6, 7], but got {n}"  # xyxy, (track_id), conf, cls
+        # TODO
+        self.is_track = n == 7
         self.boxes = boxes
         self.orig_shape = torch.as_tensor(orig_shape, device=boxes.device) if isinstance(boxes, torch.Tensor) \
             else np.asarray(orig_shape)
@@ -155,6 +166,10 @@ class Boxes:
     def cls(self):
         return self.boxes[:, -1]
 
+    @property
+    def id(self):
+        return self.boxes[:, -3] if self.is_track else None
+
     @property
     @lru_cache(maxsize=2)  # maxsize 1 should suffice
     def xywh(self):
@@ -303,7 +318,7 @@ class Masks:
 
     def __getitem__(self, idx):
         masks = self.masks[idx]
-        return Masks(masks, self.im_shape, self.orig_shape)
+        return Masks(masks, self.orig_shape)
 
     def __getattr__(self, attr):
         name = self.__class__.__name__