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.