View source on GitHub |
Preprocesses a tensor or Numpy array encoding a batch of images.
tf.keras.applications.vgg16.preprocess_input( x, data_format=None )
Usage example with applications.MobileNet
:
i = tf.keras.layers.Input([None, None, 3], dtype = tf.uint8) x = tf.cast(i, tf.float32) x = tf.keras.applications.mobilenet.preprocess_input(x) core = tf.keras.applications.MobileNet() x = core(x) model = tf.keras.Model(inputs=[i], outputs=[x]) image = tf.image.decode_png(tf.io.read_file('file.png')) result = model(image)
Arguments | |
---|---|
x | A floating point numpy.array or a tf.Tensor , 3D or 4D with 3 color channels, with values in the range [0, 255]. The preprocessed data are written over the input data if the data types are compatible. To avoid this behaviour, numpy.copy(x) can be used. |
data_format | Optional data format of the image tensor/array. Defaults to None, in which case the global setting tf.keras.backend.image_data_format() is used (unless you changed it, it defaults to "channels_last"). |
Returns | |
---|---|
Preprocessed numpy.array or a tf.Tensor with type float32 . The images are converted from RGB to BGR, then each color channel is zero-centered with respect to the ImageNet dataset, without scaling. |
Raises | |
---|---|
ValueError | In case of unknown data_format argument. |
© 2020 The TensorFlow Authors. All rights reserved.
Licensed under the Creative Commons Attribution License 3.0.
Code samples licensed under the Apache 2.0 License.
https://www.tensorflow.org/versions/r2.4/api_docs/python/tf/keras/applications/vgg16/preprocess_input