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idct

Inverse Discrete Cosine Transform

Calling Sequence

x = idct(a, n)
x = idct(a)

Arguments

x

Real or complex vector or real or complex matrix (2-dim dct).

a

Real or complex vector or real or complex matrix (2-dim dct).

n

Integer value for length of the input vector.

Description

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.

Examples

a = [2  5  1  6  8  10  7  3];
b = dct(a);
c = idct(b);

c is same as vector a.

See Also

Authors

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