Hybrid auto-labelling support (#1646)

test.py

          dataloader=None,
          save_dir=Path(''),  # for saving images
          save_txt=False,  # for auto-labelling
-         save_conf=False,
+         save_hybrid=False,  # for hybrid auto-labelling
+         save_conf=False,  # save auto-label confidences
          plots=True,
          log_imgs=0):  # number of logged images
 
     else:  # called directly
         set_logging()
         device = select_device(opt.device, batch_size=batch_size)
-        save_txt = opt.save_txt  # save *.txt labels
 
         # Directories
         save_dir = Path(increment_path(Path(opt.project) / opt.name, exist_ok=opt.exist_ok))  # increment run
 
             # Run NMS
             targets[:, 2:] *= torch.Tensor([width, height, width, height]).to(device)  # to pixels
-            lb = [targets[targets[:, 0] == i, 1:] for i in range(nb)] if save_txt else []  # for autolabelling
+            lb = [targets[targets[:, 0] == i, 1:] for i in range(nb)] if save_hybrid else []  # for autolabelling
             t = time_synchronized()
             output = non_max_suppression(inf_out, conf_thres=conf_thres, iou_thres=iou_thres, labels=lb)
             t1 += time_synchronized() - t
     parser.add_argument('--augment', action='store_true', help='augmented inference')
     parser.add_argument('--verbose', action='store_true', help='report mAP by class')
     parser.add_argument('--save-txt', action='store_true', help='save results to *.txt')
+    parser.add_argument('--save-hybrid', action='store_true', help='save label+prediction hybrid results to *.txt')
     parser.add_argument('--save-conf', action='store_true', help='save confidences in --save-txt labels')
     parser.add_argument('--save-json', action='store_true', help='save a cocoapi-compatible JSON results file')
     parser.add_argument('--project', default='runs/test', help='save to project/name')
              opt.single_cls,
              opt.augment,
              opt.verbose,
-             save_txt=opt.save_txt,
+             save_txt=opt.save_txt | opt.save_hybrid,
+             save_hybrid=opt.save_hybrid,
              save_conf=opt.save_conf,
              )