ImageDataGenerator class modes

Mode for yielding the targets (labels)

categorical	Default. Returns 2D one hot encoded labels
binary	1D binary labels
sparse	1D integer labels
input	Images identical to input images
multi_output	list with the values of the different columns,
raw	num_py array of values in y_col columns
None	No labels are returned. Only batches of image data is yielded

None-> return only images, no labels. this can be useful for prediction phase.