Decomposes signal as a linear combination of Gabor elementary functions, which are complex sinusoids with a window envelope. You can use the TFA Discrete Gabor Expansion VI to reconstruct the time-domain signal. Wire data to the signal input to determine the polymorphic instance to use or manually select the instance.

Use the pull-down menu to select an instance of this VI.


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Inputs/Outputs

  • c2ddbl.png signal —

    signal specifies the 2D input signal.

  • ccclst.png transform info (row) —

    transform info (row) specifies the analysis window to use for the Gabor transform along each row of signal. You can use the Dual Window Express VI to design the analysis window.

  • c1ddbl.png analysis window —

    analysis window specifies the window to use to compute the Gabor coefficients.

  • ci32.png dM (time steps) —

    dM (time steps) specifies the time shift, in samples, between elementary functions. The time sampling interval of the signal in the time-frequency domain is dM (time steps)/fs, where fs is the sampling rate of the signal. National Instruments recommends that you set dM (time steps) to a power of 2.

  • ci32.png N (frequency bins) —

    N (frequency bins) specifies the number of frequencies of the Gabor elementary functions. The frequency sampling interval of the signal in the time-frequency plane is fs/N (frequency bins), where fs is the sampling rate of the signal. N (frequency bins) must be a power of 2.

  • ccclst.png transform info (column) —

    transform info (column) specifies the analysis window to use for the Gabor transform along each column of signal. You can use the Dual Window Express VI to design the analysis window.

  • c1ddbl.png analysis window —

    analysis window specifies the window to use to compute the Gabor coefficients.

  • ci32.png dM (time steps) —

    dM (time steps) specifies the time shift, in samples, between elementary functions. The time sampling interval of the signal in the time-frequency domain is dM (time steps)/fs, where fs is the sampling rate of the signal. National Instruments recommends that you set dM (time steps) to a power of 2.

  • ci32.png N (frequency bins) —

    N (frequency bins) specifies the number of frequencies of the Gabor elementary functions. The frequency sampling interval of the signal in the time-frequency plane is fs/N (frequency bins), where fs is the sampling rate of the signal. N (frequency bins) must be a power of 2.

  • cerrcodeclst.png error in (no error) —

    error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

  • i4dcdb.png Gabor coef —

    Gabor coef returns the result of the 2D discrete Gabor transform.

  • ierrcodeclst.png error out —

    error out contains error information. This output provides standard error out functionality.

    • TFA Discrete Gabor Transform Details

    The Gabor elementary functions are localized in the joint time-frequency domain. The weight of the Gabor elementary function reveals the behavior of a signal around the time-frequency center of the Gabor elementary function in the joint time-frequency domain. The Gabor transform is a type of invertible linear transform.

    Examples

    Refer to the following VIs for examples of using the TFA Discrete Gabor Transform VI:

    • Gabor Transform and Expansion VI: labview\examples\Time Frequency Analysis\TFAFunctions
    • Dual Function VI: labview\examples\Time Frequency Analysis\TFAGettingStarted
    • Linear JTFA Method VI: labview\examples\Time Frequency Analysis\TFAGettingStarted