private static DataRectangle <double> Normalise(DataRectangle <double> values)
{
var max = values.Enumerate().Max(pointAndValue => pointAndValue.Item2);
return((max == 0)
? values
: values.Transform(value => (value / max)));
}
private static IEnumerable <IEnumerable <Point> > GetDistinctObjects(DataRectangle <bool> mask)
{
// Flood fill areas in the looks-like-bar-code mask to create distinct areas
var allPoints = new HashSet <Point>(
mask.Enumerate(optionalFilter: (point, isMasked) => isMasked).Select(point => point.Item1)
);
while (allPoints.Any())
{
var currentPoint = allPoints.First();
var pointsInObject = GetPointsInObject(currentPoint).ToArray();
foreach (var point in pointsInObject)
{
allPoints.Remove(point);
}
yield return(pointsInObject);
}
// Inspired by code at
// https://simpledevcode.wordpress.com/2015/12/29/flood-fill-algorithm-using-c-net/
IEnumerable <Point> GetPointsInObject(Point startAt)
{
var pixels = new Stack <Point>();
pixels.Push(startAt);
var valueAtOriginPoint = mask[startAt.X, startAt.Y];
var filledPixels = new HashSet <Point>();
while (pixels.Count > 0)
{
var currentPoint = pixels.Pop();
if ((currentPoint.X < 0) || (currentPoint.X >= mask.Width) ||
(currentPoint.Y < 0) || (currentPoint.Y >= mask.Height))
{
continue;
}
if ((mask[currentPoint.X, currentPoint.Y] == valueAtOriginPoint) &&
!filledPixels.Contains(currentPoint))
{
filledPixels.Add(new Point(currentPoint.X, currentPoint.Y));
pixels.Push(new Point(currentPoint.X - 1, currentPoint.Y));
pixels.Push(new Point(currentPoint.X + 1, currentPoint.Y));
pixels.Push(new Point(currentPoint.X, currentPoint.Y - 1));
pixels.Push(new Point(currentPoint.X, currentPoint.Y + 1));
}
}
return(filledPixels);
}
}