Generation of saliency maps

There is a problem in the code src/ptbench/scripts/generate_saliencymaps.py on line 256 and 258. To solve this problem, change "model" to "state_dict"

To reproduce the error:

ptbench train -vv densenet montgomery --batch-size=4 --epochs=1

ptbench generate-saliencymaps -vv densenet montgomery --accelerator="cuda" --weight=results/model_final_epoch.ckpt --output-folder=path/to/visualizations