CvArrFFT Method (CvArr, DFTFlag, Int32) OpenCvSharp Class Library
Performs forward or inverse Discrete Fourier transform of 1D or 2D floating-point array

Namespace:  OpenCvSharp
Assembly:  OpenCvSharp (in OpenCvSharp.dll) Version: 1.0.0.0 (1.0.0.0)
Syntax

public void FFT(
	CvArr dst,
	DFTFlag flags,
	int nonzeroRows
)

Parameters

dst
Type: OpenCvSharpCvArr
Destination array of the same size and same type as the source.
flags
Type: OpenCvSharpDFTFlag
Transformation flags
nonzeroRows
Type: SystemInt32
Number of nonzero rows to in the source array (in case of forward 2d transform), or a number of rows of interest in the destination array (in case of inverse 2d transform). If the value is negative, zero, or greater than the total number of rows, it is ignored. The parameter can be used to speed up 2d convolution/correlation when computing them via DFT.
See Also

Reference