//Apply SVD on each small piece of the bitmap
public Image SVD_Fraction(Bitmap bmp, int newRank, ref double RootMeanSquareError)
{
int bestRank = (bmp.Height * bmp.Width) / (1 + bmp.Height + bmp.Width);
if (newRank > bestRank)
return bmp;
int FactorRank = (int)Math.Round(BMP_FRAC_SIZE * ((double)newRank / bestRank));
MatrixFromBitmap(ref bmp);
int numx = bmp.Width / BMP_FRAC_SIZE;
int numy = bmp.Height / BMP_FRAC_SIZE;
MMatrix[] C = new MMatrix[numx];
MMatrix tmpMat = new MMatrix(BMP_FRAC_SIZE, BMP_FRAC_SIZE);
int FromRow, ToRow;
MMatrix Red = new MMatrix(MRed);
for (int k = 0; k < numx; ++k)
{
FromRow = k * BMP_FRAC_SIZE;
ToRow = (k + 1) * BMP_FRAC_SIZE;
tmpMat.Copy(Red, FromRow, ToRow, 0, BMP_FRAC_SIZE);
SVD(ref tmpMat, FactorRank);
C[k] = tmpMat;
for (int m = 1; m < numy; ++m)
{
tmpMat.Copy(Red, FromRow, ToRow, m * BMP_FRAC_SIZE, (m + 1) * BMP_FRAC_SIZE);
SVD(ref tmpMat, FactorRank);
C[k] = MMatrix.Concat_Horizontal(C[k], tmpMat);
}
}
for (int k = 1; k < numx; ++k)
C[0] = MMatrix.Concat_Vertical(C[0], C[k]);
MRed = FloorToBitmap(C[0].MArray);
RootMeanSquareError = MMatrix.RootMeanSquareError(new MMatrix(MRed), C[0]);
return BitmapFromMatrix(ref MRed, ref MGreen, ref MBlue);
}