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# scipy.fftpack.idct

`scipy.fftpack.``idct`(x, type=2, n=None, axis=-1, norm=None, overwrite_x=0)

  Return the Inverse Discrete Cosine Transform of an arbitrary type sequence.

  Parameters : | x : array_like The input array. type : {1, 2, 3}, optional Type of the DCT (see Notes). Default type is 2. n : int, optional Length of the transform. axis : int, optional Axis over which to compute the transform. norm : {None, ‘ortho’}, optional Normalization mode (see Notes). Default is None. overwrite_x : bool, optional If True the contents of x can be destroyed. (default=False)
  Returns : | idct : ndarray of real The transformed input array.

  See also

  `dct`

  Notes

  For a single dimension array x, `idct(x, norm='ortho')` is equal to MATLAB `idct(x)`.

  ‘The’ IDCT is the IDCT of type 2, which is the same as DCT of type 3.

  IDCT of type 1 is the DCT of type 1, IDCT of type 2 is the DCT of type 3, and IDCT of type 3 is the DCT of type 2. For the definition of these types, see `dct`.

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