/// <summary>
/// Find all connected-components in the image and return related information.
/// </summary>
/// <param name="source"></param>
/// <returns></returns>
public static List<ConnectedComponent> Find_All_Connected_Components(Bitmap source)
{
int i = 0, j = 0;
int tw = 0, th = 0;
int width = source.Width;
int height = source.Height;
// The array which tells whether the point at position[i,j] has been visited.
bool[,] visited = new bool[width, height];
List<ConnectedComponent> ccResult = new List<ConnectedComponent>();
try
{
for (i = 0; i < width; i++)
{
for (j = 0; j < height; j++)
{
if (Judge_White_Point(source.GetPixel(i, j)) && !visited[i, j])
{
visited[i, j] = true;
ConnectedComponent currentCC = new ConnectedComponent();
currentCC.PointSet.Add(new iPoint(i, j));
try
{
BFS(i, j, ref visited, currentCC, source);
}
catch (Exception ea)
{
throw new Exception(ea.Message);
}
Format_Connected_Component(currentCC);
tw = currentCC.Right_Bottom.Width_Position - currentCC.Left_Top.Width_Position;
th = currentCC.Right_Bottom.Height_Position - currentCC.Left_Top.Height_Position;
if (tw < width / 4 && (tw >= Config.CC_Size_Threshold || th >= Config.CC_Size_Threshold))
{
ccResult.Add(currentCC);
}
}
}
}
}
catch (Exception e)
{
throw new Exception(e.Message);
}
return ccResult;
}
/// <summary>
/// Write one connected component to certain bmp image.
/// </summary>
/// <param name="ccImage"></param>
/// <param name="sourceImage"></param>
public static Bitmap Save_Connected_Component_As_Bmp(ConnectedComponent ccImage, Bitmap sourceImage)
{
int width = ccImage.Right_Bottom.Width_Position - ccImage.Left_Top.Width_Position;
int height = ccImage.Right_Bottom.Height_Position - ccImage.Left_Top.Height_Position;
Bitmap ccBmp = new Bitmap(width + 1, height + 1, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
Graphics ccGraphics = Graphics.FromImage(ccBmp);
// Set the background color as black.
ccGraphics.Clear(Color.FromArgb(0, 0, 0));
ccGraphics.Dispose();
foreach (iPoint point in ccImage.PointSet)
{
ccBmp.SetPixel(point.Width_Position - ccImage.Left_Top.Width_Position,
point.Height_Position - ccImage.Left_Top.Height_Position,
sourceImage.GetPixel(point.Width_Position, point.Height_Position)
);
}
return ccBmp;
}
/// <summary>
/// Using breadth first search to find all white connected components.
/// </summary>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="visited"></param>
/// <param name="ccResult"></param>
public static void BFS(int width, int height, ref bool[,] visited, ConnectedComponent ccResult, Bitmap source)
{
int i = 0;
int len = 4;
int tx = 0, ty = 0;
int[] dirX = new int[] { 0, 1, 0, -1 };
int[] dirY = new int[] { 1, 0, -1, 0 };
visited[width, height] = true;
Queue<iPoint> pointQueue = new Queue<iPoint>();
try
{
pointQueue.Enqueue(new iPoint(width, height));
while (pointQueue.Count > 0)
{
iPoint tmp = pointQueue.Dequeue();
ccResult.PointSet.Add(new iPoint(tmp.Width_Position, tmp.Height_Position));
for (i = 0; i < len; i++)
{
tx = tmp.Width_Position + dirX[i];
ty = tmp.Height_Position + dirY[i];
if (tx >= 0 && tx < source.Width &&
ty >= 0 && ty < source.Height &&
!visited[tx, ty] &&
Judge_White_Point(source.GetPixel(tx, ty)))
{
visited[tx, ty] = true;
pointQueue.Enqueue(new iPoint(tx, ty));
}
}
}
}
catch (Exception ecc)
{
throw new Exception(ecc.Message);
}
}
/// <summary>
/// According to the point information to find the left-top and right-bottom point.
/// </summary>
/// <param name="currentCC"></param>
public static void Format_Connected_Component(ConnectedComponent currentCC)
{
int minWidth = int.MaxValue;
int maxWidth = int.MinValue;
int minHeight = int.MaxValue;
int maxHeight = int.MinValue;
foreach (iPoint point in currentCC.PointSet)
{
if (point.Width_Position < minWidth)
{
minWidth = point.Width_Position;
}
if (point.Width_Position > maxWidth)
{
maxWidth = point.Width_Position;
}
if (point.Height_Position < minHeight)
{
minHeight = point.Height_Position;
}
if (point.Height_Position > maxHeight)
{
maxHeight = point.Height_Position;
}
}
currentCC.Left_Top = new iPoint(minWidth, minHeight);
currentCC.Right_Bottom = new iPoint(maxWidth, maxHeight);
}
public ConnectedComponent(ConnectedComponent _cc)
{
iniParameter(_cc.Left_Top, _cc.Right_Bottom, _cc.PointSet);
}