var wallMatrix = new bool[6, 5]; // setting up some obstacles for flood
wallMatrix[2, 0] = wallMatrix[2, 1] = wallMatrix[2, 2] 
	= wallMatrix[3, 0] = wallMatrix[3, 1] = wallMatrix[3, 2] = true;

Predicate<int, int> positionQualifier = (x, y) => wallMatrix[x, y] == false;

var floodParameters = new FloodParameters(startX: 0, startY: 0)
{
	Qualifier = positionQualifier
};
var markMatrix = new int[6, 5];

new FloodSpiller().SpillFlood(floodParameters, markMatrix);

private int[,] _positionMarkMatrix;

public void BucketFillImage(int floodStartX, int floodStartY, Color replacedColor, Color targetColor)
{
	var floodSpiller = new FloodSpiller();
	var floodParameters = new FloodParameters(floodStartX, floodStartY)
	{
		BoundsRestriction = new FloodBounds(_imageSizeX, _imageSizeY),
		NeighbourhoodType = NeighbourhoodType.Four,
		Qualifier = (x, y) => GetColor(x, y) == replacedColor,
		NeighbourProcessor = (x, y, mark) => SetColor(x, y, targetColor),
		ProcessStartAsFirstNeighbour = true
	};

	floodSpiller.SpillFlood(floodParameters, _positionMarkMatrix);
}