AttributeError: 'function' object has no attribute 'image_data_format'

This error occurs when trying to access the `image_data_format` attribute of a function object, which is not defined for functions.

Most likely, this error is caused by trying to access the `image_data_format` attribute of a function instead of a Keras backend object. Make sure you are using the correct object and that it has the `image_data_format` attribute defined.

For example, instead of using a function like `keras.backend.function()`, try using `keras.backend` directly to access the backend object and its attributes:

from keras import backend as K

print(K.image_data_format())