Computes the inverse Discrete Cosine Transform (DCT) of the input sequence DCT {X}. Wire data to the DCT {X} input to determine the polymorphic instance to use or manually select the instance.


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Inputs/Outputs

  • c1ddbl.png DCT {X} —

    DCT {X} is the real input sequence.

  • i1ddbl.png X —

    X is the inverse DCT of DCT {X}.

  • ii32.png error —

    error returns any error or warning from the VI. You can wire error to the Error Cluster From Error Code VI to convert the error code or warning into an error cluster.

    • 1D Inverse DCT

    If y represents the input sequence DCT {X}, the one-dimensional inverse DCT of y is defined as:

    and

    where N is the length of the input sequence DCT {X}, y(k) is the k-th element of DCT {X}, and x(n) is the n-th element of the output sequence X. This VI applies a fast inverse DCT algorithm instead of calculating the inverse DCT directly. LabVIEW implements this fast inverse DCT algorithm using an FFT technique.

    Examples

    Refer to the following example files included with LabVIEW.

    • labview\examples\Signal Processing\Transforms\Image Compression with DCT.vi