/// <summary>Mesh generation function.</summary>
static void RunMesh(double[,] Input, ImageSegmentPosition Position, Point4Distance Mesh)
{
/* Find median of input block */
double[] V = new double[Input.Length];
Buffer.BlockCopy(Input, 0, V, 0, V.Length * sizeof(double));
Array.Sort(V);
/* In very bright regions, keep image's zero level as the median, thus avoiding background stretching by stars */
if (Abs(V[V.Length / 2] - Mesh.InputStat.ZeroLevel) > 10 * Mesh.InputStat.StDev)
{
V[V.Length / 2] = Mesh.InputStat.ZeroLevel;
}
/* Load the median as a mesh point */
Mesh.MedianPoints[(int)Round(Position.Alignment.Y) / Mesh.MeshSize, (int)Round(Position.Alignment.X) / Mesh.MeshSize] = V[V.Length / 2];
}
/// <summary>
/// Output normalization function.
/// </summary>
static void Normalize(double[,] Input, double[,] Output, ImageSegmentPosition InputPosition, ImageSegmentPosition OutputPosition, Point4Distance Mesh)
{
int OH = Input.GetLength(0), OW = Input.GetLength(1);
int i, j;
/* Deal with image edges */
if (InputPosition.Alignment.Y <= Mesh.MeshSize)
{
for (i = 0; i < OH; i++)
{
for (j = 0; j < Mesh.MeshSize; j++)
{
Output[i, j] = Input[i, j] - Mesh.MedianPoints[2, 2];
}
for (; j < OW - Mesh.MeshSize; j++)
{
Output[i, j] = Input[i, j] - Mesh.MedianPoints[2, j / Mesh.MeshSize];
}
for (; j < OW; j++)
{
Output[i, j] = Input[i, j] - Mesh.MedianPoints[2, Mesh.MedianPoints.GetLength(1) - 3];
}
}
return;
}
if (InputPosition.Alignment.Y + 2 * Mesh.MeshSize >= Mesh.Input.Height)
{
for (i = 0; i < OH; i++)
{
for (j = 0; j < Mesh.MeshSize; j++)
{
Output[i, j] = Input[i, j] - Mesh.MedianPoints[Mesh.MedianPoints.GetLength(0) - 2, 2];
}
for (; j < OW - Mesh.MeshSize; j++)
{
Output[i, j] = Input[i, j] - Mesh.MedianPoints[Mesh.MedianPoints.GetLength(0) - 2, j / Mesh.MeshSize];
}
for (j = 0; j < Mesh.MeshSize; j++)
{
Output[i, j] = Input[i, j] - Mesh.MedianPoints[Mesh.MedianPoints.GetLength(0) - 2, Mesh.MedianPoints.GetLength(1) - 3];
}
}
return;
}
for (i = 0; i < OH; i++)
{
for (j = 0; j < 3 * Mesh.MeshSize / 2; j++)
{
Output[i, j] = Input[i, j] - Mesh.MedianPoints[(i + (int)InputPosition.Alignment.Y) / Mesh.MeshSize, 2];
}
/* Perform main loop */
for (; j < OW - 3 * Mesh.MeshSize / 2; j++)
{
int PX = (int)InputPosition.Alignment.X + j;
int PY = (int)InputPosition.Alignment.Y + i;
double[] Distances = new double[4];
double DistSum, ValSum;
/* Find nearest mesh points and the distances to them */
int dPX = PX % Mesh.MeshSize;
int dPY = PY % Mesh.MeshSize;
int kPX = PX / Mesh.MeshSize;
int kPY = PY / Mesh.MeshSize;
Distances[0] = Sqrt(dPX * dPX + dPY * dPY);
Distances[1] = Sqrt((Mesh.MeshSize - dPX) * (Mesh.MeshSize - dPX) + dPY * dPY);
Distances[2] = Sqrt((Mesh.MeshSize - dPY) * (Mesh.MeshSize - dPY) + dPX * dPX);
Distances[3] = Sqrt((Mesh.MeshSize - dPX) * (Mesh.MeshSize - dPX) + (Mesh.MeshSize - dPY) * (Mesh.MeshSize - dPY));
DistSum = Distances[0] + Distances[1] + Distances[2] + Distances[3];
/* Interpolate based on the distance to each mesh point */
ValSum = (DistSum - Distances[0]) * Mesh.MedianPoints[kPY, kPX] + (DistSum - Distances[1]) * Mesh.MedianPoints[kPY, kPX + 1];
ValSum += (DistSum - Distances[2]) * Mesh.MedianPoints[kPY + 1, kPX] + (DistSum - Distances[3]) * Mesh.MedianPoints[kPY + 1, kPX + 1];
double Interpolated = ValSum / DistSum / 3;
/* Remove background */
Output[i, j] = Input[i, j] - Interpolated;
}
for (; j < OW; j++)
{
Output[i, j] = Input[i, j] - Mesh.MedianPoints[(i + (int)InputPosition.Alignment.Y) / Mesh.MeshSize, Mesh.MedianPoints.GetLength(1) - 3];
}
}
}
