private List<WatershedPixel> GetNeighbouringPixels(WatershedPixel centerPixel)
{
List<WatershedPixel> temp = new List<WatershedPixel>();
if (_numberOfNeighbours == 8)
{
/*
CP = Center pixel
(X,Y) -- get all 8 connected
|-1,-1|0,-1|1,-1|
|-1, 0| CP |1, 0|
|-1,+1|0,+1|1,+1|
*/
// -1, -1
if ((centerPixel.X - 1) >= 0 && (centerPixel.Y - 1) >= 0)
temp.Add(_pixelMap[(centerPixel.X - 1).ToString() + "," + (centerPixel.Y - 1).ToString()]);
// 0, -1
if ((centerPixel.Y - 1) >= 0)
temp.Add(_pixelMap[centerPixel.X.ToString() + "," + (centerPixel.Y - 1).ToString()]);
// 1, -1
if ((centerPixel.X + 1) < _pictureWidth && (centerPixel.Y - 1) >= 0)
temp.Add(_pixelMap[(centerPixel.X + 1).ToString() + "," + (centerPixel.Y - 1).ToString()]);
// -1, 0
if ((centerPixel.X - 1) >= 0)
temp.Add(_pixelMap[(centerPixel.X - 1).ToString() + "," + centerPixel.Y.ToString()]);
// 1, 0
if ((centerPixel.X + 1) < _pictureWidth)
temp.Add(_pixelMap[(centerPixel.X + 1).ToString() + "," + centerPixel.Y.ToString()]);
// -1, 1
if ((centerPixel.X - 1) >= 0 && (centerPixel.Y + 1) < _pictureHeight)
temp.Add(_pixelMap[(centerPixel.X - 1).ToString() + "," + (centerPixel.Y + 1).ToString()]);
// 0, 1
if ((centerPixel.Y + 1) < _pictureHeight)
temp.Add(_pixelMap[centerPixel.X.ToString() + "," + (centerPixel.Y + 1).ToString()]);
// 1, 1
if ((centerPixel.X + 1) < _pictureWidth && (centerPixel.Y + 1) < _pictureHeight)
temp.Add(_pixelMap[(centerPixel.X + 1).ToString() + "," + (centerPixel.Y + 1).ToString()]);
}
else
{
/*
CP = Center pixel, N/A = not used
(X,Y) -- get only 4 connected
| N/A |0,-1| N/A |
|-1, 0| CP |+1, 0|
| N/A |0,+1| N/A |
*/
// -1, 0
if ((centerPixel.X - 1) >= 0)
temp.Add(_pixelMap[(centerPixel.X - 1).ToString() + "," + centerPixel.Y.ToString()]);
// 0, -1
if ((centerPixel.Y - 1) >= 0)
temp.Add(_pixelMap[centerPixel.X.ToString() + "," + (centerPixel.Y - 1).ToString()]);
// 1, 0
if ((centerPixel.X + 1) < _pictureWidth)
temp.Add(_pixelMap[(centerPixel.X + 1).ToString() + "," + centerPixel.Y.ToString()]);
// 0, 1
if ((centerPixel.Y + 1) < _pictureHeight)
temp.Add(_pixelMap[centerPixel.X.ToString() + "," + (centerPixel.Y + 1).ToString()]);
}
return temp;
}
public void AddToEnd(WatershedPixel p)
{
queue.Add(p);
}
private void CreatePixelMapAndHeightSortedArray(BitmapData data)
{
_pictureWidth = data.Width;
_pictureHeight = data.Height;
// pixel map holds every pixel thus size of (_pictureWidth * _pictureHeight)
_pixelMap = new Dictionary<string, WatershedPixel>(_pictureWidth * _pictureHeight);
unsafe
{
int offset = data.Stride - data.Width;
byte* ptr = (byte*)(data.Scan0);
// get histogram of all values in grey = height
for (int y = 0; y < data.Height; y++)
{
for (int x = 0; x < data.Width; x++, ptr++)
{
WatershedPixel p = new WatershedPixel(x, y, *ptr);
// add every pixel to the pixel map
_pixelMap.Add(p.X.ToString() + "," + p.Y.ToString(), p);
_heightSortedList[*ptr].Add(p);
}
ptr += offset;
}
}
this._currentLabel = 0;
}