public static MatrixData CalculateDistanceField(this MatrixData input, int searchDistance)
{
MatrixData output = new MatrixData(input.NumberOfRows, input.NumberOfColumns);
for (int r = 0; r < input.NumberOfRows; r++)
{
for (int c = 0; c < input.NumberOfColumns; c++)
{
//skip black pixels
if (input[r, c] == 0)
{
continue;
}
int steps = 0;
int fxMin = Math.Max(r - searchDistance, 0);
int fxMax = Math.Min(r + searchDistance, input.NumberOfRows);
int fyMin = Math.Max(c - searchDistance, 0);
int fyMax = Math.Min(c + searchDistance, input.NumberOfColumns);
for (int fx = fxMin; fx < fxMax - 1; ++fx)
{
for (int fy = fyMin; fy < fyMax - 1; ++fy)
{
if (input[fx, fy] == 255)
{
steps += ((fx - fxMin) + (fy - fyMin));
//int tempStep = ((fx - fxMin) + (fy - fyMin));
//if(tempStep > steps) steps = tempStep;
}
}
}
output[r, c] = steps;
}
}
return(output.HistEQ());
}