readme update

Author: yhenon-nextdroid

README.md

@@ -67,15 +67,23 @@ Note that the --csv_val argument is optional, in which case no validation will b
 
 ## Pre-trained model
 
-A pre-trained model is available at: https://drive.google.com/open?id=1yLmjq3JtXi841yXWBxst0coAgR26MNBS
+A pre-trained model is available at: 
+- https://drive.google.com/open?id=1yLmjq3JtXi841yXWBxst0coAgR26MNBS (this is a pytorch state dict)
+- https://drive.google.com/open?id=1hCtM35R_t6T8RJVSd74K4gB-A1MR-TxC (this is a pytorch model serialized via `torch.save()`)
 
-This model can be loaded using:
+The state dict model can be loaded using:
 
 ```
 retinanet = model.resnet50(num_classes=dataset_train.num_classes(),)
 retinanet.load_state_dict(torch.load(PATH_TO_WEIGHTS))
 ```
 
+The pytorch model can be loaded directly using:
+
+```
+retinanet = torch.load(PATH_TO_MODEL)
+```
+
 ## Visualization
 
 To visualize the network detection, use `visualize.py`: