/// <summary>
/// Merge a region into the current instance
/// </summary>
public void Merge(ConnectedRegion region)
{
coordinates.AddRange(region.coordinates);
validBoundingRect = false;
}
/// <summary>
/// Normalizes the labeled regions of the image so that only root regions exist
/// </summary>
private void NormalizeLabelSequence()
{
// Tag the root labels
int rootNodeCount = 0;
for (int i = 0; i < labels.Count; i++)
{
if (IsRootNode(i))
{
labels[i].Tag = rootNodeCount++;
}
}
// Initialize as many regions as there are root labels
ConnectedRegion[] regions = new ConnectedRegion[rootNodeCount];
for (int i = 0; i < rootNodeCount; i++)
{
regions[i] = new ConnectedRegion();
regions[i].RegionID = i;
}
// Fix pathological cases where sequential region numbering is borked
Dictionary<int, int> realRegions = new Dictionary<int, int>();
int currentRegion = 0;
// Run through the image data and set non-root labels to their root,
// and add each coordinate to the corresponding region.
for (int x = 0; x < Width; x++)
{
for (int y = 0; y < Height; y++)
{
int regionID = labels[RootOf(labelData[x, y])].Tag;
if (realRegions.ContainsKey(regionID))
{
regionID = realRegions[regionID];
}
else
{
regionID = realRegions[regionID] = currentRegion;
currentRegion++;
}
regions[regionID].AddCoordinate(new Point(x, y));
labelData[x, y] = regionID;
}
}
// Cheat: The zeroth region is the image BG itself in this application.
List<ConnectedRegion> regionList = new List<ConnectedRegion>(regions);
regionList.RemoveAt(0);
//// Optimization: A tiny region isn't going to contain any useful information.
//// Remove small regions and resequence the list.
//currentRegion = 0;
//List<ConnectedRegion> killList = new List<ConnectedRegion>();
//foreach (ConnectedRegion region in regionList)
//{
// if (region.GetCoordinates().Count < USEFUL_REGION_THRESHOLD)
// {
// killList.Add(region);
// }
// else
// {
// region.RegionID = currentRegion++;
// foreach (Point p in region.GetCoordinates())
// {
// labelData[p.X, p.Y] = region.RegionID;
// }
// }
//}
//foreach (ConnectedRegion region in killList)
//{
// regionList.Remove(region);
//}
Regions = new ReadOnlyCollection<ConnectedRegion>(regionList);
}