about the loss

[Jimzhou82sub]

In many image restoration works like super resolution, denoising and so on, when I train the network ,I found after 1or2epoch ,the loss keeps an approximately stable value, Is this normal?

[proteus1991]

To my best understanding, if the network is designed well (i.e., effective), the loss would keep decreasing to achieve the local minimum, which usually needs more than 2 epochs.