Support Partial labels with Faster R-CNN.

PiperOrigin-RevId: 325536056

research/object_detection/meta_architectures/faster_rcnn_meta_arch.py

@@ -2412,7 +2412,15 @@ class FasterRCNNMetaArch(model.DetectionModel):
            unmatched_class_label=tf.constant(
                [1] + self._num_classes * [0], dtype=tf.float32),
            gt_weights_batch=groundtruth_weights_list)
-
+      if self.groundtruth_has_field(
+          fields.InputDataFields.groundtruth_labeled_classes):
+        gt_labeled_classes = self.groundtruth_lists(
+            fields.InputDataFields.groundtruth_labeled_classes)
+        gt_labeled_classes = tf.pad(
+            gt_labeled_classes, [[0, 0], [1, 0]],
+            mode='CONSTANT',
+            constant_values=1)
+        batch_cls_weights *= tf.expand_dims(gt_labeled_classes, 1)
       class_predictions_with_background = tf.reshape(
           class_predictions_with_background,
           [batch_size, self.max_num_proposals, -1])