Image scaling issues

[SMercier88]

1- Currently, I believe the images are not scaled to a [0-1] range when we run the tfrecords generation followed by model training. This is OK for efficientnet models, because preprocessing is done by the model itself. That said, other models, like inception expect a scaled input.

2- I might we wrong, but I believe the scale variable, used for data augmentation and created here, should be the opposite. It should be 1 for models of the efficientnet family (because the model expect a tensor of [0-255] floats), while it should be 255 for the other models.