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dct

PURPOSE ^

% y = dct (x, n)

SYNOPSIS ^

function y = dct (x, n)

DESCRIPTION ^

% 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

CROSS-REFERENCE INFORMATION ^

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