Correct way to specify loss

[hvgazula]

What is the correct way to specify a loss? This will be relevant for streamlining the process of defining new losses.

losses.dice as seen in

nobrainer/nobrainer/processing/segmentation.py

Line 54 in 976691d

loss=losses.dice,

or

losses.Dice() as seen in

nobrainer/nobrainer/losses.py

Line 35 in 976691d

model.compile('sgd', loss=nobrainer.losses.Dice())

Check how using either impact saving/loading the model.