Inverse Discrete Cosine Transform
x = idct(a, n) x = idct(a)
Real or complex vector or real or complex matrix (2-dim dct).
Real or complex vector or real or complex matrix (2-dim dct).
Integer value for length of the input vector.
The Inverse Discrete Cosine Transform (IDCT) reconstruct the original sequence from its discrete cosine transform sequence. To rebuild a sequence in the spatial domain from the frequencies obtained by the dct transform, we use the IDCT: x = idct(a) returns the inverse discrete cosine transform of a. x = idct(a, n) pads or truncates a to length n before transforming. If a is a matrix, idct(a) transforms its columns.