public static unsafe ComplexImage GetSubComplexImage(this UnmanagedImage image,
int x,
int y,
int width,
int height,
bool zeroPadding = true)
{
const float norm = ComplexImage.MAX_MAGNITUDE / (float)byte.MaxValue;
if (x < 0 ||
y < 0 ||
image.Width < width ||
image.Height < height)
{
throw new DimensionMismatchException();
}
var result = zeroPadding
? new ComplexImage((int)MathCV.UpperPow2((uint)width), (int)MathCV.UpperPow2((uint)height))
: new ComplexImage(width, height);
var c0Data = result.Channel0;
var c1Data = result.Channel1;
var c2Data = result.Channel2;
ComplexImage.Compatible.CheckFormat(image, out var pb);
var srcDataPtr = (byte *)(image.ImageData + (y * image.Stride) + (x * pb));
var srcPadd = image.Stride - (width * pb);
var dstPadd = result.Width - width;
for (int i = 0,
n = result.Width * height;
i < n;
i += dstPadd, srcDataPtr += srcPadd)
{
for (var iTo = i + width; i < iTo; i++, srcDataPtr += pb)
{
c0Data[i] = srcDataPtr[RGB.R] * norm;
c1Data[i] = srcDataPtr[RGB.G] * norm;
c2Data[i] = srcDataPtr[RGB.B] * norm;
}
}
return(result);
}
/// <summary>
/// Create a sin funktion with frequency f along the given direction
/// </summary>
/// <param name="f"></param>
/// <param name="angle">direction of the sin in degrees</param>
/// <returns></returns>
public static Complex2D GenerateSin(int w, int h, double f, double angle)
{
var result = new Complex2D(w, h);
var a = ((2 * Math.PI * f) / w) * Math.Cos(angle = MathCV.ToRad(angle));
var b = ((2 * Math.PI * f) / h) * Math.Sin(angle);
var d = result.Data;
for (int y = 0,
i = 0;
y < h;
y++)
{
var v = y * b;
for (var x = 0; x < w; x++, i++)
{
d[i] = Math.Sin(v + (x * a));
}
}
return(result);
}
/// <summary>
/// Create an ComplexImage from this image with a width/height that is the smallest power of two which isgreater or equal
/// than the size of the input image.
/// </summary>
/// <param name="image"></param>
public static ComplexImage ToComplexImageZeroPad(this UnmanagedImage image) => ToComplexImageZeroPad(
image,
MathCV.UpperPow2(image.Width),
MathCV.UpperPow2(image.Height)
);
