/// <summary>
/// Calculates the fast fourier transform of the image.
/// </summary>
/// <param name="image">The image to get calculate the FFT from.</param>
/// <param name="shiftAxes">Whether to perform FFTShift on the Fourier image.</param>
/// <param name="ignoreAlpha">Whether to ignore the alpha component of the image (if it is 32-bit).</param>
/// <param name="disposeImage">Whether to dispose the image after use.</param>
/// <param name="targetWidth">The height to resize the kernel to, or -1 to leave kernel same width. Can only be larger than the kernel width.</param>
/// <param name="targetHeight">The height to resize the kernel to, or -1 to leave kernel same height. Can only be larger than the kernel height.</param>
public FourierWorker(PixelWorker image, bool shiftAxes = true, bool ignoreAlpha = false, bool disposeImage = false, int targetWidth = -1, int targetHeight = -1)
{
if (image == null)
{
return;
}
int componentCount = image.ComponentCount, targetPixelCount = image.PixelCount;
if (ignoreAlpha && componentCount == 4)
{
componentCount = 3;
alphaReference = image;
alphaReference.ShallowClone();
}
values = new ComplexF[componentCount][];
ComponentCount = componentCount;
TargetWidth = image.Width;
TargetHeight = image.Height;
TargetPixelCount = image.PixelCount;
TargetPixelComponentCount = image.PixelComponentCount;
TargetSize = new Size(TargetWidth, TargetHeight);
FourierWidth = (int)Maths.CeilingPowerOfTwo((uint)(targetWidth <= TargetWidth ? TargetWidth : targetWidth));
FourierHeight = (int)Maths.CeilingPowerOfTwo((uint)(targetHeight <= TargetHeight ? TargetHeight : targetHeight));
FourierSize = new Size(FourierWidth, FourierHeight);
FourierPixelCount = FourierWidth * FourierHeight;
FourierPixelComponentCount = FourierPixelCount * ComponentCount;
fourierWidthLog2 = Maths.Log2((uint)FourierWidth);
fourierHeightLog2 = Maths.Log2((uint)FourierHeight);
ComplexF[] current;
byte comp;
int c, x = 0, y = 0, fourierWidth = FourierWidth, fourierHeight = FourierHeight, tw = TargetWidth;
int tcc = image.ComponentCount, txMinusOne = TargetWidth - 1, tyMinusOne = TargetHeight - 1;
for (c = 0; c < componentCount; c++)
{
current = new ComplexF[FourierPixelCount];
values[c] = current;
for (y = 0; y < fourierHeight; y++)
{
for (x = 0; x < fourierWidth; x++)
{
comp = image.GetPixelBgra((Math.Min(y, tyMinusOne) * tw + Math.Min(x, txMinusOne)) * tcc)[c];
if (comp > OriginalMax)
{
OriginalMax = comp;
}
current[y * fourierWidth + x] = new ComplexF()
{
Real = comp,
};
}
}
}
NormalizationCap = OriginalMax;
FFT(true);
if (shiftAxes)
{
ShiftAxes = true;
FFTShift();
}
if (disposeImage)
{
image.Dispose();
}
}
