| Signal Processing Toolbox | Help Desk |
idct
Inverse discrete cosine transform.
x = idct(y) x = idct(y,n)The inverse discrete cosine transform reconstructs a sequence from its discrete cosine transform (DCT) coefficients. The
idct function is the inverse of the dct function.
x = idct(y)
returns the inverse discrete cosine transform of y
where
and N = length(x). x is the same size as y. The series is indexed from n + 1 and k + 1 instead of the usual n and k because MATLAB vectors run from 1 to N instead of from 0 to N-1.
x = idct(y,n)
appends zeros or truncates the vector y to length n before transforming.
If y is a matrix, idct transforms its columns.
Two-dimensional DCT (see Image Processing Toolbox User's Manual). |
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Two-dimensional inverse DCT (see Image Processing Toolbox User's Manual). |
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