Stream data from files during training
To create a validation data set, split off around 10% of the training data into a validation set. The
validate_split.py helper script does this:
python validate_split.py day1
Keras has built-in support for streaming images from files in this directory structure through the
ImageDataGenerator class and its
flow_from_directory method. However, when training it is valuable to have a validation data set, which is taken from the same set of images as the training data but is set aside and used to estimate how well a network is generalizing to images that it has not seen during training.