View source on GitHub |

Computes the 1D Inverse Discrete Cosine Transform (DCT) of `input`

.

tf.signal.idct( input, type=2, n=None, axis=-1, norm=None, name=None )

Currently Types I, II, III, IV are supported. Type III is the inverse of Type II, and vice versa.

Note that you must re-normalize by 1/(2n) to obtain an inverse if `norm`

is not `'ortho'`

. That is: `signal == idct(dct(signal)) * 0.5 / signal.shape[-1]`

. When `norm='ortho'`

, we have: `signal == idct(dct(signal, norm='ortho'), norm='ortho')`

.

Args | |
---|---|

`input` | A `[..., samples]` `float32` /`float64` `Tensor` containing the signals to take the DCT of. |

`type` | The IDCT type to perform. Must be 1, 2, 3 or 4. |

`n` | For future expansion. The length of the transform. Must be `None` . |

`axis` | For future expansion. The axis to compute the DCT along. Must be `-1` . |

`norm` | The normalization to apply. `None` for no normalization or `'ortho'` for orthonormal normalization. |

`name` | An optional name for the operation. |

Returns | |
---|---|

A `[..., samples]` `float32` /`float64` `Tensor` containing the IDCT of `input` . |

Raises | |
---|---|

`ValueError` | If `type` is not `1` , `2` or `3` , `n` is not `None,` axis`is not` -1`, or` norm`is not` None`or` 'ortho'`. |

Equivalent to scipy.fftpack.idct for Type-I, Type-II, Type-III and Type-IV DCT.

© 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/r2.3/api_docs/python/tf/signal/idct