fourier




Input


An integer between 0 and 116 specifying the input image frame number. A value of 0 represents the DMA memory buffer of the video device. Values in the range of 100116 correspond to hidden frames.


Output


An integer between 1 and 116 specifying the output image frame number. Values in the range of 100116 correspond to hidden frames.


Invert


An enumerated integer that describes the direction of the transform:


M_DIRECT – applies the direct Fourier transform by converting the image from the spatial domain into the frequency domain.

M_INVERSE – applies the inverse Fourier transform by converting the image from the frequency domain into the spatial domain.


FFT


An enumerated integer that specifies if the fast Fourier transform will be enforced. Must be one of the following values:


FALSE – applies the DFT (discrete Fourier transform) algorithm as described above. If the horizontal and vertical sizes of the input image are powers of 2, the FFT (fast Fourier transform) algorithm will be applied.

TRUE – applies the Fast Fourier transform algorithm for an arbitrary image size by expanding the image horizontally and vertically to the closest width and height which are powers of 2. This is done by surrounding the image with the black margins prior to the application of the function. When the inverse transform is applied to the frequency image generated with the enforced FFT algorithm, the resulting image will retain the size of the original grayscale image.

Default value: TRUE


ERR_OK


The flag set if successful.


ERR_FAILED


The flag set if failed.


This set of statements applies converts a captured image into the frequency domain and then back to the spatial domain:


GrabIm(1)

fourier (1,2, M_DIRECT, F_FFT)

fourier (2,3,M_INVERSE,F_FFT)

