public static Bitmap DrawTwoImages(Bitmap img1, Bitmap img2, List <ValueTuple <Descriptor, Descriptor> > match)
{
var offset = 20;
var width = img1.Width + img2.Width + offset;
var height = Math.Max(img1.Height, img2.Height) + offset;
var result = new Bitmap(width + 2 * offset, height + 2 * offset);
using (var g = Graphics.FromImage(result))
{
g.DrawImage(img1,
offset,
offset,
img1.Width,
img1.Height);
g.DrawImage(img2,
2 * offset + img1.Width,
2 * offset,
img2.Width,
img2.Height);
}
foreach (var(d1, d2) in match)
{
InterestingPoint
from = d1.Point,
to = d2.Point;
DrawLine(result,
offset + from.getX(),
offset + from.getY(),
(int)from.Radius,
2 * offset + to.getX() + img1.Width,
2 * offset + to.getY(),
(int)to.Radius
);
}
return(result);
}
private static List <int> GetInliers(List <ValueTuple <Descriptor, Descriptor> > matches, List <double> homography)
{
var inliers = new List <int>();
for (var i = 0; i < matches.Count; i++)
{
var match = matches[i];
InterestingPoint
a = match.Item1.Point,
b = match.Item2.Point;
var point = Transform(homography, a.getX(), a.getY());
var distance = MathHelper.SqrtOfSqrSum(point.Item1 - b.getX(), point.Item2 - b.getY());
if (distance < Threshold)
{
inliers.Add(i);
}
}
return(inliers);
}
private static List <double> FindCurrentHomography(List <ValueTuple <Descriptor, Descriptor> > matches,
List <int> choices, bool reverse)
{
double[,] Homography = new double[2 * choices.Count, MatrixWidth];
var index = 0;
foreach (var value in choices)
{
var match = matches[value];
InterestingPoint a = match.Item1.Point, b = match.Item2.Point;
if (reverse)
{
(a, b) = (b, a);
}
int i1 = 2 * index, i2 = 2 * index + 1;
Homography[i1, 0] = a.getX();
Homography[i1, 1] = a.getY();
Homography[i1, 2] = 1;
Homography[i1, 3] = 0;
Homography[i1, 4] = 0;
Homography[i1, 5] = 0;
Homography[i1, 6] = -b.getX() * a.getX();
Homography[i1, 7] = -b.getX() * a.getY();
Homography[i1, 8] = -b.getX();
Homography[i2, 0] = 0;
Homography[i2, 1] = 0;
Homography[i2, 2] = 0;
Homography[i2, 3] = a.getX();
Homography[i2, 4] = a.getY();
Homography[i2, 5] = 1;
Homography[i2, 6] = -b.getY() * a.getX();
Homography[i2, 7] = -b.getY() * a.getY();
Homography[i2, 8] = -b.getY();
index++;
}
var m = Homography.GetLength(1);
var n = Homography.GetLength(1);
var k = Homography.GetLength(0);
var mat = new double[m, n];
alglib.rmatrixgemm(m, n, k, 1,
Homography, 0, 0, 1,
Homography, 0, 0, 0,
0,
ref mat, 0, 0
);
// SV decomposition. A = U * S * V^T
m = mat.GetLength(0);
n = mat.GetLength(1);
alglib.rmatrixsvd(mat, m, n, 2, 0, 2, out var w, out var u, out _);
var minIndex = Array.IndexOf(w, w.Min());
var scale = 1 / u[MatrixWidth - 1, minIndex];
var result = new List <double>();
for (var i = 0; i < MatrixWidth; i++)
{
result.Add(scale * u[i, minIndex]);
}
return(result);
}
private static Vector CalculateForPointWithRotation(Mat gradient, Mat dx, Mat dy, double expScale,
int gridSize, double radius, int binsCount, InterestingPoint center, double alpha, bool affine)
{
var centerX = center.getX() / (1 << center.Octave);
var centerY = center.getY() / (1 << center.Octave);
var size = (int)(radius * 2 + 1);
var blockSize = size / gridSize;
var step = 2 * Math.PI / binsCount;
double cos = Math.Cos(-alpha),
sin = Math.Sin(-alpha);
var bins = new Dictionary <ValueTuple <int, int>, List <double> >();
for (var u = -radius; u < radius; u++)
{
for (var v = -radius; v < radius; v++)
{
int x = (int)(centerX + u),
y = (int)(centerY + v);
var magnitude = gradient.GetPixel(x, y, BorderWrapType.Wrap);
var theta = Math.Atan2(dy.GetPixel(x, y, BorderWrapType.Wrap), dx.GetPixel(x, y, BorderWrapType.Wrap));
if (theta < 0)
{
theta += Math.PI * 2;
}
var rotatedU = u * cos + v * sin;
var rotatedV = v * cos - u * sin;
var row = (rotatedV + size / 2D) / blockSize;
var column = (rotatedU + size / 2D) / blockSize;
if (column < 0 || column >= gridSize || row < 0 || row >= gridSize)
{
continue;
}
magnitude *= Math.Exp(expScale * (rotatedU * rotatedU + rotatedV * rotatedV));
var rotatedTheta = theta + alpha;
if (rotatedTheta > Math.PI * 2)
{
rotatedTheta -= Math.PI * 2;
}
var ratio = rotatedTheta % step / step;
var leftBin = Math.Min((int)Math.Floor(rotatedTheta / step), binsCount - 1);
var rightBin = (leftBin + 1) % binsCount;
if (!bins.ContainsKey(((int)row, (int)column)))
{
bins.Add(((int)row, (int)column), Enumerable.Repeat(0D, binsCount).ToList());
}
if (!affine)
{
PutToBins(bins, (int)row, (int)column, 1, leftBin, rightBin, ratio, magnitude);
}
else
{
var i = (int)row;
if (row - i <= 0.5)
{
i--;
}
var j = (int)column;
if (column - j <= 0.5)
{
j--;
}
var ki = 1 - Math.Abs(column - (j + 0.5));
var kj = 1 - Math.Abs(row - (i + 0.5));
PutToBins(bins, i, j, ki * kj, leftBin, rightBin, ratio, magnitude);
PutToBins(bins, i, j + 1, (1 - ki) * kj, leftBin, rightBin, ratio, magnitude);
PutToBins(bins, i + 1, j, ki * (1 - kj), leftBin, rightBin, ratio, magnitude);
PutToBins(bins, i + 1, j + 1, (1 - ki) * (1 - kj), leftBin, rightBin, ratio, magnitude);
}
}
}
var result = new Vector(gridSize * gridSize * binsCount);
for (var i = 0; i < gridSize; i++)
{
for (var j = 0; j < gridSize; j++)
{
for (var k = 0; k < binsCount; k++)
{
double value = 0;
if (bins.ContainsKey((i, j)))
{
value = bins[(i, j)][k];