% y = dct (x, n) % Computes the 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 discrete cosine transform X of x can be defined as follows: % % N-1 % X[k] = w(k) sum x[n] cos (pi (2n-1) k / 2N ), k = 0, ..., N-1 % n=0 % % with w(0) = sqrt(1/N) and w(k) = sqrt(2/N), k = 1, ..., N-1. There % are other definitions with different scaling of X[k], but this form % is common in image processing. % % See also: idct, dct2, idct2, dctmtx

- dct2 % y = dct2 (x)

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