.. note::
    :class: sphx-glr-download-link-note

    Click :ref:`here <sphx_glr_download_auto_examples_plot_dl_keras.py>` to download the full example code
.. rst-class:: sphx-glr-example-title

.. _sphx_glr_auto_examples_plot_dl_keras.py:



.. _l-example-backend-api-tensorflow:

ONNX Runtime for Keras
======================

The following demonstrates how to compute the predictions
of a pretrained deep learning model obtained from 
`keras <https://keras.io/>`_
with *onnxruntime*. The conversion requires
`keras <https://keras.io/>`_,
`tensorflow <https://www.tensorflow.org/>`_,
`keras-onnx <https://github.com/onnx/keras-onnx/>`_,
`onnxmltools <https://pypi.org/project/onnxmltools/>`_
but then only *onnxruntime* is required
to compute the predictions.



.. code-block:: python

    import os
    if not os.path.exists('dense121.onnx'):
        from keras.applications.densenet import DenseNet121
        model = DenseNet121(include_top=True, weights='imagenet')

        from keras2onnx import convert_keras
        onx = convert_keras(model, 'dense121.onnx')    
        with open("dense121.onnx", "wb") as f:
            f.write(onx.SerializeToString())







Let's load an image (source: wikipedia).



.. code-block:: python


    from keras.preprocessing.image import array_to_img, img_to_array, load_img
    img = load_img('Sannosawa1.jpg')
    ximg = img_to_array(img)

    import matplotlib.pyplot as plt
    plt.imshow(ximg / 255)
    plt.axis('off')




.. image:: /auto_examples/images/sphx_glr_plot_dl_keras_001.png
    :class: sphx-glr-single-img




Let's load the model with onnxruntime.



.. code-block:: python

    import onnxruntime as rt
    from onnxruntime.capi.onnxruntime_pybind11_state import InvalidGraph

    try:
        sess = rt.InferenceSession('dense121.onnx')
        ok = True
    except (InvalidGraph, TypeError, RuntimeError) as e:
        # Probably a mismatch between onnxruntime and onnx version.
        print(e)
        ok = False

    if ok:
        print("The model expects input shape:", sess.get_inputs()[0].shape)
        print("image shape:", ximg.shape)





.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    The model expects input shape: ['N', 224, 224, 3]
    image shape: (960, 1280, 3)


Let's resize the image.



.. code-block:: python


    if ok:
        from skimage.transform import resize
        import numpy

        ximg224 = resize(ximg / 255, (224, 224, 3), anti_aliasing=True)
        ximg = ximg224[numpy.newaxis, :, :, :]
        ximg = ximg.astype(numpy.float32)

        print("new shape:", ximg.shape)





.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    new shape: (1, 224, 224, 3)


Let's compute the output.



.. code-block:: python


    if ok:
        input_name = sess.get_inputs()[0].name
        res = sess.run(None, {input_name: ximg})
        prob = res[0]
        print(prob.ravel()[:10])  # Too big to be displayed.






.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    [5.3862054e-06 6.1927537e-08 2.0104133e-07 1.3239808e-06 1.0415122e-06
     6.7792627e-08 3.1348068e-07 3.2683040e-08 1.0914272e-07 1.1627122e-06]


Let's get more comprehensive results.



.. code-block:: python


    if ok:
        from keras.applications.densenet import decode_predictions
        decoded = decode_predictions(prob)

        import pandas
        df = pandas.DataFrame(decoded[0], columns=["class_id", "name", "P"])
        print(df)






.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    class_id        name         P
    0  n09468604      valley  0.785549
    1  n09193705         alp  0.187054
    2  n09399592  promontory  0.010602
    3  n09246464       cliff  0.005537
    4  n02417914        ibex  0.001997


**Total running time of the script:** ( 0 minutes  56.895 seconds)


.. _sphx_glr_download_auto_examples_plot_dl_keras.py:


.. only :: html

 .. container:: sphx-glr-footer
    :class: sphx-glr-footer-example



  .. container:: sphx-glr-download

     :download:`Download Python source code: plot_dl_keras.py <plot_dl_keras.py>`



  .. container:: sphx-glr-download

     :download:`Download Jupyter notebook: plot_dl_keras.ipynb <plot_dl_keras.ipynb>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.readthedocs.io>`_