IDCT

Purpose:

Calculates the Unitary Inverse Discrete Cosine Transform.

Syntax:

IDCT(series, n)

series

-

An input series or array.

n

-

Optional. An integer, the transform length. Defaults to length(series).

Returns:

A series or array.

Example:

idct(dct(gcos(100, 1/100, 20)))

 

returns a 20 Hz cosine wave.

Remarks:

The unitary inverse discrete cosine transform is defines as:

 

 

 

The transform is applied to each column if the input is an array. The IDCT is often used in conjunction with DCT to perform image compression.

See Also:

DCT

DCT2

IDCT2

IDST

IFFT