from keras.preprocessing.image import ImageDataGenerator

datagen = ImageDataGenerator(featurewise_center=False,
                             featurewise_std_normalization=False,
                             rotation_range=20,
                             width_shift_range=0.2,
                             height_shift_range=0.2,
                             horizontal_flip=True,
                             zoom_range=0.1,
                             validation_split=0.2)

datagen.fit(X_train)