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

  • c2ddbl.png DCT {X} —

    DCT {X} is the real input sequence.

  • i2ddbl.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.

    • 2D Inverse DCT

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

    where M and N are the number of rows and columns, respectively, of DCT {X}. x(m,n) is the element of the output matrix X with row number m and column number n. y(u,v) is the element of the input matrix DCT {X} with row number u and column number v. This VI performs a two-dimensional inverse DCT using the following two steps:

    1. Perform a one-dimensional inverse DCT row-by-row on the input matrix DCT {X}. The output is Y'.
    2. Perform a one-dimensional inverse DCT column-by-column on Y'. The output is X.

    Examples

    Refer to the following example files included with LabVIEW.

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