/// <summary>
/// Двумерное обратное быстрое преобразование фурье
/// </summary>
/// <param name="source">входная матрица</param>
/// <param name="height">The height.</param>
/// <param name="width">The width.</param>
/// <returns>
/// Выходной ряд
/// </returns>
public static Complex[,] IFastTransform(Complex[,] source, int height, int width)
{
if (source.GetLength(0) != source.GetLength(1))
{
return(null);
}
int size = source.GetLength(0);
Complex[,] outC = new Complex[size, size];
//преобразуем столбцы
for (int i = 0; i < size; i++) //проходим по столбцам
{
Complex[] raw = new Complex[size];
for (int j = 0; j < size; j++) //проходим внутри столбца, собирая его
{
raw[j] = source[j, i];
}
raw = Fourier.IFastTransform(raw); //получаем фурье образ столбца
for (int j = 0; j < size; j++) //записываем его в массив
{
outC[j, i] = raw[j];
}
}
//преобразуем строки
for (int i = 0; i < size; i++) //проходим по строкам
{
Complex[] str = new Complex[size];
for (int j = 0; j < size; j++) //проходим внутри строки, собирая её
{
str[j] = outC[i, j];
}
str = Fourier.IFastTransform(str); //получаем фурье образ строки
for (int j = 0; j < size; j++) //записываем его в массив
{
outC[i, j] = str[j];
}
}
Complex[,] value = new Complex[height, width];
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
value[i, j] = outC[i, j];
}
}
return(value);
}
/// <summary>
/// Конволюция (свёртка) в частотной области
/// </summary>
/// <param name="sourceImage">исходное изображение</param>
/// <returns>искаженное изображение</returns>
public Image FastConvolution(Image sourceImage)
{
int height = sourceImage.Height;
int width = sourceImage.Width;
int filterSize = this.filterMatrix.GetLength(0); //размер PSF
int filterHalfSize = (filterSize - 1) / 2 + 1; //центр PSF
Image expandedImage = sourceImage.Expand(filterHalfSize);
int expHeight = expandedImage.Height;
int expWidth = expandedImage.Width;
double[] image = Converter.ToDoubleArray(expandedImage);
double[,] red = new double[expHeight, expWidth];
double[,] green = new double[expHeight, expWidth];
double[,] blue = new double[expHeight, expWidth];
int index = 0;
for (int i = 0; i < expHeight; i++)
{
for (int j = 0; j < expWidth; j++)
{
blue[i, j] = image[index];
green[i, j] = image[index + 1];
red[i, j] = image[index + 2];
index += 4;
}
}
Complex[,] redFourier = Fourier.FastTransform(Converter.ToComplexMatrix(red));
Complex[,] greenFourier = Fourier.FastTransform(Converter.ToComplexMatrix(green));
Complex[,] blueFourier = Fourier.FastTransform(Converter.ToComplexMatrix(blue));
int newSize = redFourier.GetLength(0);
double[,] kernel = this.ExpendedByZero(newSize);
Complex[,] kernelFourier = Fourier.FastTransform(Converter.ToComplexMatrix(kernel));
for (int u = 0; u < newSize; u++)
{
for (int v = 0; v < newSize; v++)
{
redFourier[u, v] *= kernelFourier[u, v];
greenFourier[u, v] *= kernelFourier[u, v];
blueFourier[u, v] *= kernelFourier[u, v];
}
}
Complex[,] newRed = Fourier.IFastTransform(redFourier, expHeight, expWidth);
Complex[,] newGreen = Fourier.IFastTransform(greenFourier, expHeight, expWidth);
Complex[,] newBlue = Fourier.IFastTransform(blueFourier, expHeight, expWidth);
Complex[,] resRed = new Complex[height, width];
Complex[,] resGreen = new Complex[height, width];
Complex[,] resBlue = new Complex[height, width];
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
resRed[i, j] = Math.Round(newRed[i + filterHalfSize + 1, j + filterHalfSize + 1].Real);
resGreen[i, j] = Math.Round(newGreen[i + filterHalfSize + 1, j + filterHalfSize + 1].Real);
resBlue[i, j] = Math.Round(newBlue[i + filterHalfSize + 1, j + filterHalfSize + 1].Real);
}
}
Image result = Converter.ToImage(resRed, resGreen, resBlue);
return(result);
}