Cv2Dft Method OpenCvSharp Class Library
Performs a forward Discrete Fourier transform of 1D or 2D floating-point array.

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

public static void Dft(
	InputArray src,
	OutputArray dst,
	DftFlag2 flags = DftFlag2.None,
	int nonzeroRows = 0
)

Parameters

src
Type: OpenCvSharp.CPlusPlusInputArray
The source array, real or complex
dst
Type: OpenCvSharp.CPlusPlusOutputArray
The destination array, which size and type depends on the flags
flags (Optional)
Type: OpenCvSharp.CPlusPlusDftFlag2
Transformation flags, a combination of the DftFlag2 values
nonzeroRows (Optional)
Type: SystemInt32
When the parameter != 0, the function assumes that only the first nonzeroRows rows of the input array ( DFT_INVERSE is not set) or only the first nonzeroRows of the output array ( DFT_INVERSE is set) contain non-zeros, thus the function can handle the rest of the rows more efficiently and thus save some time. This technique is very useful for computing array cross-correlation or convolution using DFT
See Also

Reference