tf.nn.ctc_beam_search_decoder

Performs beam search decoding on the logits given in input.

tf.nn.ctc_beam_search_decoder(
    inputs, sequence_length, beam_width=100, top_paths=1
)
  • ctc_beam_search_decoder treats blanks as sequence termination
  • ctc_greedy_decoder treats blanks as regular elements

inputs 3-D float Tensor, size [max_time, batch_size, num_classes]. The logits.
sequence_length 1-D int32 vector containing sequence lengths, having size [batch_size].
beam_width An int scalar >= 0 (beam search beam width).
top_paths An int scalar >= 0, <= beam_width (controls output size).

A tuple (decoded, log_probabilities) where
decoded A list of length top_paths, where decoded[j] is a SparseTensor containing the decoded outputs:

decoded[j].indices: Indices matrix [total_decoded_outputs[j], 2]; The rows store: [batch, time].

decoded[j].values: Values vector, size [total_decoded_outputs[j]]. The vector stores the decoded classes for beam j.

decoded[j].dense_shape: Shape vector, size (2). The shape values are: [batch_size, max_decoded_length[j]].

log_probability A float matrix [batch_size, top_paths] containing sequence log-probabilities.