private static ComplexF[,] prepareImage(Gray <float>[,] image, int biggestKernelWidth, int biggestKernelHeight,
ConvolutionBorder options,
out int fillX, out int fillY)
{
int FFTNumOfCols = (int)System.Math.Pow(2.0, System.Math.Ceiling(System.Math.Log(biggestKernelWidth + image.Width(), 2.0)));
int FFTNumOfRows = (int)System.Math.Pow(2.0, System.Math.Ceiling(System.Math.Log(biggestKernelHeight + image.Height(), 2.0)));
fillX = System.Math.Min(image.Width(), biggestKernelWidth / 2);
fillY = System.Math.Min(image.Height(), biggestKernelHeight / 2);
var paddedImage = new Gray <float> [FFTNumOfRows, FFTNumOfCols];
//center
image.CopyTo(paddedImage, new Point(fillX, fillY));
if (options == ConvolutionBorder.BorderMirror)
{
mirrorBorders(image, paddedImage, fillX, fillY);
}
var paddedImageCmplx = paddedImage.ToComplex();
paddedImageCmplx.FFT(FourierTransform.Direction.Forward, true);
return(paddedImageCmplx);
}