inference from images stored on disk

[balthazarneveu]

To get a quick insights on how much the performances of a trained network fall down when we apply it on natural images we need an inference script for natural images

-> would be useful to evaluate before we start #18

• [x] Div2K https://www.kaggle.com/datasets/joe1995/div2k-dataset/data
• [x] Kodak https://www.kaggle.com/datasets/sherylmehta/kodak-dataset/data git clone https://github.com/clausmichele/CBSD68-dataset.git