% y = dct (x, n) % Computes the inverse discrete cosine transform of x. If n is % given, then x is padded or trimmed to length n before computing % the transform. If x is a matrix, compute the transform along the % columns of the the matrix. The transform is faster if x is % real-valued and even length. % % The inverse discrete cosine transform x of X can be defined as follows: % % N-1 % x[n] = sum w(k) X[k] cos (pi (2n-1) k / 2N ), k = 0, ..., N-1 % k=0 % % with w(0) = sqrt(1/N) and w(k) = sqrt(2/N), k = 1, ..., N-1 % % See also: idct, dct2, idct2, dctmtx