What does ImageDataGenerator.fit() function does in Keras Image preprocessing?

Question

There is ImageDataGenerator.flow() function, in which we pass our training images and it returns augmented images. But what does ImageDataGenerator.fit() function does?

Answer 1

For some transformations such as centering or scaling, the ImageDataGenerator needs statistics on the data such the feature-wise mean, standard deviation etc. The fit() method collects these statistics. This API is similar to how the preprocessing functions in scikit-learn work.