| public TransformPoints ( ) : System.Drawing.PointF[] | ||
| return | System.Drawing.PointF[] | |
/// <summary>
/// Compute inliers using the Symmetric Transfer Error,
/// </summary>
///
private int[] distance(MatrixH H, double t)
{
// Compute the projections (both directions)
PointF[] p1 = H.TransformPoints(pointSet1);
PointF[] p2 = H.Inverse().TransformPoints(pointSet2);
// Compute the distances
for (int i = 0; i < pointSet1.Length; i++)
{
// Compute the distance as
float ax = pointSet1[i].X - p2[i].X;
float ay = pointSet1[i].Y - p2[i].Y;
float bx = pointSet2[i].X - p1[i].X;
float by = pointSet2[i].Y - p1[i].Y;
d2[i] = (ax * ax) + (ay * ay) + (bx * bx) + (by * by);
}
// Find and return the inliers
return(Matrix.Find(d2, z => z < t));
}
/// <summary>
/// Normalizes a set of homogeneous points so that the origin is located
/// at the centroid and the mean distance to the origin is sqrt(2).
/// </summary>
public static PointH[] Normalize(this PointH[] points, out MatrixH T)
{
float n = points.Length;
float xmean = 0, ymean = 0;
for (int i = 0; i < points.Length; i++)
{
points[i].X = points[i].X / points[i].W;
points[i].Y = points[i].Y / points[i].W;
points[i].W = 1;
xmean += points[i].X;
ymean += points[i].Y;
}
xmean /= n; ymean /= n;
float scale = 0;
for (int i = 0; i < points.Length; i++)
{
float x = points[i].X - xmean;
float y = points[i].Y - ymean;
scale += (float)System.Math.Sqrt(x * x + y * y);
}
scale = (float)(SQRT2 * n / scale);
T = new MatrixH
(
scale, 0, -scale * xmean,
0, scale, -scale * ymean,
0, 0, 1
);
return(T.TransformPoints(points));
}
/// <summary>
/// Compute inliers using the Symmetric Transfer Error,
/// </summary>
///
private int[] distance(MatrixH H, double t)
{
// Compute the projections (both directions)
PointF[] p1 = H.TransformPoints(pointSet1);
PointF[] p2 = H.Inverse().TransformPoints(pointSet2);
// Compute the distances
for (int i = 0; i < pointSet1.Length; i++)
{
// Compute the distance as
float ax = pointSet1[i].X - p2[i].X;
float ay = pointSet1[i].Y - p2[i].Y;
float bx = pointSet2[i].X - p1[i].X;
float by = pointSet2[i].Y - p1[i].Y;
d2[i] = (ax * ax) + (ay * ay) + (bx * bx) + (by * by);
}
// Find and return the inliers
return Matrix.Find(d2, z => z < t);
}
public void MultiplyTest()
{
MatrixH matrix = new MatrixH(Matrix.Identity(3));
PointH[] points = new PointH[]
{
new PointH(1, 2),
new PointH(5, 2),
new PointH(12, 2),
new PointH(1, 2),
new PointH(10, 2),
};
PointH[] expected = new PointH[]
{
new PointH(1, 2),
new PointH(5, 2),
new PointH(12, 2),
new PointH(1, 2),
new PointH(10, 2),
};
PointH[] actual = (PointH[])points.Clone();
matrix.TransformPoints(actual);
Assert.AreEqual(expected[0], actual[0]);
Assert.AreEqual(expected[1], actual[1]);
Assert.AreEqual(expected[2], actual[2]);
Assert.AreEqual(expected[3], actual[3]);
Assert.AreEqual(expected[4], actual[4]);
}
