private float[,] BackProjection(TomographResult tomographResult)
{
var NN = tomographResult.SampleCount;
var pixels = new float[NN, NN];
foreach (var projection in tomographResult.Projections)
{
var angle = projection.Key;
var sinGL = Math.Sin(Math.PI / 180.0f * angle);
var cosGL = Math.Cos(Math.PI / 180.0f * angle);
for (int i = 0; i < NN; i++)
{
for (int j = 0; j < NN; j++)
{
var v = (j - (NN / 2.0f)) * cosGL + (i - (NN / 2.0f)) * sinGL;
var r = Math.Round(v) + NN / 2.0f;
if ((r < (NN - 1)) && (r > -1))
{
pixels[i, j] = pixels[i, j] + projection.Value[(int)r];
}
}
}
}
return(pixels);
}
public static async Task <TomographResult> Read(string path)
{
return(await Task.Run(() =>
{
var fileLines = File.ReadLines(path);
if (fileLines.Count() == 0)
{
throw new Exception("пустой файл");
}
if (fileLines.First() != "data")
{
throw new Exception("неверный формат данных");
}
var result = new TomographResult
{
SampleCount = int.Parse(fileLines.ElementAt(1)),
ProjectionCount = int.Parse(fileLines.ElementAt(2)),
AngleStep = float.Parse(fileLines.ElementAt(3), CultureInfo.InvariantCulture)
};
var projectionsWithAngles = fileLines.Skip(5);
var angle = 0f;
for (int i = 0; i < projectionsWithAngles.Count(); i += 2)
{
var projection = projectionsWithAngles
.ElementAt(i)
.Split(' ')
.Where(x => string.IsNullOrWhiteSpace(x) == false)
.Select(x => float.Parse(x, CultureInfo.InvariantCulture)).ToArray();
result.Projections.Add(angle, projection);
angle += result.AngleStep;
}
return result;
}));
}
