//Create Sobel kernel for Canny
public static MMatrix D2Gauss_Canny(int rows, double stdDeviation1, int cols, double stdDeviation2, double theta)
{
MMatrix r = new MMatrix(2, 2);
MMatrix u = new MMatrix(2, 1);
MMatrix h = new MMatrix();
MMatrix g = new MMatrix(cols, rows);
int hrows = rows / 2;
int hcols = cols / 2;
r[0, 0] = Math.Cos(theta);
r[0, 1] = -Math.Sin(theta);
r[1, 0] = -r[0, 1];
r[1, 1] = r[0, 0];
for (int i = 0; i < cols; ++i)
{
u[1, 0] = i - hcols;
for (int j = 0; j < rows; ++j)
{
u[0, 0] = j - hrows;
h = r * u;
g[i, j] = Gauss(h[0, 0], stdDeviation1) * DGauss(h[1, 0], stdDeviation2);
}
}
return g / g.Frobenius();
}