Contents

vDSP.DCTTransformType.III

A constant that represents a type-III discrete cosine transform.

Declaration

case III

Discussion

The type-III DCT uses the following operation for a discrete cosine transform:

// `N` is the length given in the setup.
// `h` is the input array that contains real numbers.
// `H` is the output array that contains real numbers.

For 0 <= k < N
    Or[k] = Ir[0]/2
        + sum(Ir[j] * cos((k+1/2) * j * pi / N), 1 <= j < N)

See Also

Discrete Cosine Transform Type Constants