{'loss_classifier': tensor(0.1195, grad_fn=), 'loss_box_reg': tensor(0.0222, grad_fn=), 'loss_objectness': tensor(0.0159, grad_fn=), 'loss_rpn_box_reg': tensor(0.0009, grad_fn=)} {'boxes': tensor([], size=(0, 4), grad_fn=), 'labels': tensor([], dtype=torch.int64), 'scores': tensor([], grad_fn=)}