private void performOneIteration(int angleIndex, GrayscaleBitmap bmp)
{
double[] projection = projectionHandler.CreateProjection(bmp, angleIndex * angleBetweenProjections);
double[] error = new double[projection.Length];
for (int i = 0; i < projection.Length; i++)
{
error[i] = projections[angleIndex][i] - projection[i];
}
GrayscaleBitmap errorBmp = projectionHandler.ExtrudeProjection(error, angleIndex * angleBetweenProjections);
for (int i = 0; i < bmp.Width; i++)
{
for (int j = 0; j < bmp.Height; j++)
{
bmp[i, j] += errorBmp[i, j];
if (!allowNegativeValues && bmp[i, j] < 0)
bmp[i, j] = 0;
}
}
}
public List <double[]> GenerateProjections(GrayscaleBitmap bmp, int sliceCount, ProgressCounter progressCounter = null)
{
if (sliceCount < 1)
{
throw new ArgumentOutOfRangeException("sliceCount", "sliceCount must be at least 1");
}
List <double[]> projections = new List <double[]>(sliceCount);
double angleStep = 180.0 / sliceCount;
for (int i = 0; i < sliceCount; i++)
{
double angle = i * angleStep;
projections.Add(CreateProjection(bmp, angle));
progressCounter?.AddStep();
}
return(projections);
}
/// <summary>
/// Reconstructs the image from projections specified in constructor
/// </summary>
/// <param name="progressCounter"></param>
/// <returns>Reconstructed image</returns>
public GrayscaleBitmap Reconstruct(ProgressCounter progressCounter = null)
{
int size = projections[0].Length;
GrayscaleBitmap bmp = new GrayscaleBitmap(size, size);
for (int i = 0; i < projections.Count; i++)
{
double angle = angleBetweenProjections * i;
//Extrude projection in given angle
GrayscaleBitmap extrudedProjection = projectionHandler.ExtrudeProjection(projections[i], angle);
//add given extruded projection to the result
bmp += extrudedProjection;
progressCounter?.AddStep();
}
bmp.Stretch();
return(bmp);
}
/// <summary>
/// Converts given sinogram bitmap to projections
/// </summary>
/// <param name="bmp">Input sinogram</param>
/// <returns>List of projections</returns>
public static List <double[]> SinogramToProjections(GrayscaleBitmap bmp)
{
int projectionCount = bmp.Height / 3;
int projectionSize = bmp.Width;
List <double[]> projections = new List <double[]>(projectionCount);
for (int i = 0; i < projectionCount; i++)
{
double[] projection = new double[projectionSize];
for (int j = 0; j < projectionSize; j++)
{
//valuable data is placed in the second third of the image
projection[j] = bmp[projectionCount + i, j];
}
projections.Add(projection);
}
return(projections);
}
public GrayscaleBitmap Reconstruct(int iterationCount, ProgressCounter progressCounter = null)
{
int size = projections[0].Length;
double avrg = 0;
for (int i = 0; i < projections[0].Length; i++)
avrg += projections[0][i];
avrg /= (size * size);
GrayscaleBitmap bmp = new GrayscaleBitmap(size, size);
for (int i = 0; i < bmp.Width; i++)
{
for (int j = 0; j < bmp.Height; j++)
{
bmp[i, j] = avrg;
}
}
for (int i = 0; i < iterationCount; i++)
{
Console.WriteLine("Iteration: " + i);
performOneIteration(i % projections.Count, bmp);
lastIterationNumber = i;
progressCounter?.AddStep();
}
GrayscaleBitmap ret = new GrayscaleBitmap(bmp.Width, bmp.Height);
for (int i = 0; i < bmp.Width; i++)
{
for (int j = 0; j < bmp.Height; j++)
{
if (bmp[i, j] < 0)
ret[i, j] = 0;
else if (bmp[i, j] > 1)
ret[i, j] = 1;
else
ret[i, j] = bmp[i, j];
}
}
currentReconstruction = bmp;
return ret;
}
