private void SetWeights ()
{
weights = new double[3][];
for (int i = 0; i < this.weights.Length; ++i) {
this.weights[i] = new double[3];
}
// adjust and convert angle to radians
double r = (double)angle * 2.0 * Math.PI / 360.0;
// angle delta for each weight
double dr = Math.PI / 4.0;
// for r = 0 this builds an edge detect filter pointing straight left
this.weights[0][0] = Math.Cos (r + dr);
this.weights[0][1] = Math.Cos (r + 2.0 * dr);
this.weights[0][2] = Math.Cos (r + 3.0 * dr);
this.weights[1][0] = Math.Cos (r);
this.weights[1][1] = 0;
this.weights[1][2] = Math.Cos (r + 4.0 * dr);
this.weights[2][0] = Math.Cos (r - dr);
this.weights[2][1] = Math.Cos (r - 2.0 * dr);
this.weights[2][2] = Math.Cos (r - 3.0 * dr);
}
#endregion