private Line nextLine(IOIOMatrix image, int numAttempts, Point startPoint)
{
Line bestLine = new Line(Point.Empty, Point.Empty);
double bestScore = double.NegativeInfinity;
double bestAvgCover = double.NegativeInfinity;
for (int i = 0; i < numAttempts; ++i)
{
Line line = generateRandomLine(image.Width, image.Height, startPoint);
double score = image.Average(line);
double avgCover = score / line.Length;
if (UseIOIO2)
{
if (avgCover > bestAvgCover * 0.95 && score > bestScore)
{
bestScore = score;
bestAvgCover = avgCover;
bestLine = line;
}
}
else
{
if (score > bestScore)
{
bestScore = score;
bestAvgCover = avgCover;
bestLine = line;
}
}
}
image.Subtract(bestLine, GRAY_RESOLUTION);
return(bestLine);
}
public string Process(string uri, Action <double> callback)
{
Bitmap _original = null;
IOIOMatrix original = null;
using (MemoryStream ms = new MemoryStream(Convert.FromBase64String(uri)))
{
_original = new Bitmap(ms);
original = new IOIOMatrix(_original);
}
// Resize to native resolution.
float scale = (float)NATIVE_RESOLUTION / original.Width;
var _preview = ResizeImage(_original, scale);
var preview = new IOIOMatrix(_preview);
// Down-sample.
var _inp = ResizeImage(_preview, (float)SCALE);
var inp = new IOIOMatrix(_inp);
inp.Invert();
inp.Multiply(GRAY_RESOLUTION / SCALE / 255);
// Now is the actual algorithm!
Point lastP = Point.Empty;
double residualDarkness = inp.Average() / GRAY_RESOLUTION * SCALE;
double totalLength = 0;
List <Line> lines = new List <Line>();
double deltaDarkness = residualDarkness - THRESHOLD;
while (residualDarkness > THRESHOLD)
{
Line bestLine = nextLine(inp, NUM_CANDIDATES, lastP);
Line scaledLine = scaleLine(bestLine, 1 / SCALE);
lastP = bestLine.B;
Line line = new Line(
new Point(scaledLine.A.X, scaledLine.A.Y),
new Point(scaledLine.B.X, scaledLine.B.Y));
totalLength += line.Length;
lines.Add(line);
residualDarkness = inp.Average() / GRAY_RESOLUTION * SCALE;
callback?.Invoke(1 - (residualDarkness - THRESHOLD) / deltaDarkness);
}
return(GetImage(preview.Width, preview.Height, lines));
}