contrib.keras.backend.ctc_decode

tf.contrib.keras.backend.ctc_decode

tf.contrib.keras.backend.ctc_decode

ctc_decode(
    y_pred,
    input_length,
    greedy=True,
    beam_width=100,
    top_paths=1
)

Defined in tensorflow/contrib/keras/python/keras/backend.py.

Decodes the output of a softmax.

Can use either greedy search (also known as best path) or a constrained dictionary search.

Arguments:

y_pred: tensor `(samples, time_steps, num_categories)`
    containing the prediction, or output of the softmax.
input_length: tensor `(samples, )` containing the sequence length for
    each batch item in `y_pred`.
greedy: perform much faster best-path search if `true`.
    This does not use a dictionary.
beam_width: if `greedy` is `false`: a beam search decoder will be used
    with a beam of this width.
top_paths: if `greedy` is `false`,
    how many of the most probable paths will be returned.

Returns:

Tuple:
    List: if `greedy` is `true`, returns a list of one element that
        contains the decoded sequence.
        If `false`, returns the `top_paths` most probable
        decoded sequences.
        Important: blank labels are returned as `-1`.
    Tensor `(top_paths, )` that contains
        the log probability of each decoded sequence.