private SortedSet <int> MergeNeighbors(int i, int j)
{
PixelCluster a = clusters[i];
PixelCluster b = clusters[j];
SortedSet <int> merged = Simplify(a.neighbors);
merged.UnionWith(Simplify(b.neighbors));
merged.Remove(a.id);
merged.Remove(b.id);
return(merged);
}
//follow the parent pointer until we reach the root
private int Find(int id)
{
PixelCluster p = clusters[id];
if (p.id == p.parentId)
{
return(p.id);
}
int parentId = p.parentId;
while (parentId != clusters[parentId].parentId)
{
parentId = clusters[parentId].parentId;
}
//compress the path
p.parentId = parentId;
return(parentId);
}
//Cluster the final clusters into color space
public void ClusterColorSpace()
{
double maxDist = 20 * 20;
int minRegions = 5;
SortedSet <int> activeClusterIds = new SortedSet <int>(rootIds);
String logFile = "colorlog.txt";
StreamWriter log = File.AppendText(logFile);
log.WriteLine("\n\tCluster ColorSpace Run " + DateTime.Now.ToString());
log.Flush();
//the smaller id comes first in the dictionary for pairwise distances
PriorityQueue <Tuple <int, int>, double> pq = new PriorityQueue <Tuple <int, int>, double>();
int counter = activeClusterIds.Last() + 1;
int[] ids = activeClusterIds.ToArray <int>();
//Calculate the initial distances
for (int i = 0; i < ids.Count(); i++)
{
for (int j = i + 1; j < ids.Count(); j++)
{
//log.WriteLine(ids[i] + ", " + ids[j] + " dist " + -1 * clusters[ids[i]].lab.SqDist(clusters[ids[j]].lab));
//log.Flush();
//pq.Enqueue(new Tuple<int, int>(ids[i], ids[j]), -1 * clusters[ids[i]].lab.SqDist(clusters[ids[j]].lab));
PixelCluster a = clusters[ids[i]];
PixelCluster b = clusters[ids[j]];
double newDist = a.lab.SqDist(b.lab);
//Add in Ward's variance (variation in Color Segmentation using Region Merging)
//http://www.mathworks.com/help/toolbox/stats/linkage.html
//newDist = newDist * Math.Sqrt(2 * a.count * b.count / (a.count + b.count));
pq.Enqueue(new Tuple <int, int>(ids[i], ids[j]), -1 * newDist);
}
}
Stopwatch timer = new Stopwatch();
timer.Start();
while (activeClusterIds.Count > minRegions)
{
//Find the pair with the smallest distance
KeyValuePair <Tuple <int, int>, double> result = BestPair(pq, activeClusterIds);
Tuple <int, int> pair = result.Key;
double bestDist = -1 * result.Value;
Console.WriteLine("num clusters: " + activeClusterIds.Count());
if (bestDist > maxDist)
{
break;
}
PixelCluster a = clusters[pair.Item1];
PixelCluster b = clusters[pair.Item2];
//Create a new cluster with unique id, we don't care about the neighbors
PixelCluster merged = new PixelCluster();
merged.id = counter++;
merged.lab = (a.lab * a.count + b.lab * b.count) / (a.count + b.count);
merged.count = a.count + b.count;
merged.children = new int[] { a.id, b.id };
merged.parentId = merged.id;
a.parentId = merged.id;
b.parentId = merged.id;
clusters.Add(merged.id, merged);
//Update the active cluster set
activeClusterIds.Remove(a.id);
activeClusterIds.Remove(b.id);
activeClusterIds.Add(merged.id);
double totalCount = a.count + b.count;
//Update the distances, based on old distances
foreach (int i in activeClusterIds)
{
if (i == merged.id)
{
continue;
}
//TODO: Ward's method with minimum variance
//For now, just use the dist between the centroids
PixelCluster c = clusters[i];
double newDist = merged.lab.SqDist(c.lab);
//Add in Ward's variance (variation in Color Segmentation using Region Merging)
//http://www.mathworks.com/help/toolbox/stats/linkage.html
//newDist = newDist * Math.Sqrt(2*a.count * b.count / (a.count + b.count));
if (c.id < merged.id)
{
pq.Enqueue(new Tuple <int, int>(c.id, merged.id), -1 * newDist);
}
else
{
pq.Enqueue(new Tuple <int, int>(merged.id, c.id), -1 * newDist);
}
}
//Remove the old clusters
foreach (int i in activeClusterIds)
{
if (i > a.id)
{
pq.Remove(new Tuple <int, int>(a.id, i));
}
else
{
pq.Remove(new Tuple <int, int>(i, a.id));
}
}
foreach (int i in activeClusterIds)
{
if (i > b.id)
{
pq.Remove(new Tuple <int, int>(b.id, i));
}
else
{
pq.Remove(new Tuple <int, int>(i, b.id));
}
}
//Repeat until termination criteria
if (activeClusterIds.Count() % 1000 == 0)
{
//write to file
log.WriteLine("Merge loop: " + timer.ElapsedMilliseconds / 1000.0 + " # Clusters: " + activeClusterIds.Count() + " pqCount: " + pq.Count + " merged # neighbors: " + merged.neighbors.Count);
log.Flush();
timer.Restart();
}
}
rootIds = activeClusterIds;
timer.Stop();
log.WriteLine("End: " + timer.ElapsedMilliseconds / 1000.0 + " # Clusters: " + activeClusterIds.Count() + " pqCount: " + pq.Count);
log.WriteLine("End Time: " + DateTime.Now.ToString());
log.Flush();
log.Close();
}
/**
* Now the Agglomerative Clustering. May want to pass in additional parameters, like the termination
* criteria and parameters.
* Assumes list of colors are in row-order
**/
public void Cluster(List <CIELAB> colors, int width, int height)
{
double maxDist = 50 * 10;
SortedSet <int> activeClusterIds = new SortedSet <int>();
String logFile = "log.txt";
StreamWriter log = File.AppendText(logFile);
log.WriteLine("\n\tCluster Spatial Run " + DateTime.Now.ToString());
log.Flush();
//the smaller id comes first in the dictionary for pairwise distances
PriorityQueue <Tuple <int, int>, double> pq = new PriorityQueue <Tuple <int, int>, double>();
clusters = new Dictionary <int, PixelCluster>();
int counter = 0;
//Initialize the clusters in row-order
for (int j = 0; j < height; j++)
{
for (int i = 0; i < width; i++)
{
activeClusterIds.Add(counter);
PixelCluster p = new PixelCluster(counter, colors[width * j + i]);
counter++;
//Initialize the 4-neighbors
if (i > 0)
{
p.neighbors.Add(ToIndex(i - 1, j, width));
}
if (j > 0)
{
p.neighbors.Add(ToIndex(i, j - 1, width));
}
if (i < width - 1)
{
p.neighbors.Add(ToIndex(i + 1, j, width));
}
if (j < height - 1)
{
p.neighbors.Add(ToIndex(i, j + 1, width));
}
clusters.Add(p.id, p);
}
}
foreach (int i in activeClusterIds)
{
//calculate distances to neighbors larger than current id
SortedSet <int> neighbors = Simplify(clusters[i].neighbors);
foreach (int j in neighbors)
{
if (i < j)
{
pq.Enqueue(new Tuple <int, int>(i, j), -1 * clusters[i].lab.SqDist(clusters[j].lab));
}
}
}
Stopwatch timer = new Stopwatch();
timer.Start();
while (activeClusterIds.Count > 1)
{
//Find the pair with the smallest distance
KeyValuePair <Tuple <int, int>, double> result = BestPair(pq, activeClusterIds);
Tuple <int, int> pair = result.Key;
double bestDist = -1 * result.Value;
Console.WriteLine("num clusters: " + activeClusterIds.Count());
if (bestDist > maxDist)
{
break;
}
PixelCluster a = clusters[pair.Item1];
PixelCluster b = clusters[pair.Item2];
//Create a new cluster with unique id
PixelCluster merged = new PixelCluster();
merged.id = counter++;
merged.lab = (a.lab * a.count + b.lab * b.count) / (a.count + b.count);
merged.count = a.count + b.count;
merged.children = new int[] { a.id, b.id };
merged.neighbors = MergeNeighbors(a.id, b.id);
merged.parentId = merged.id;
a.parentId = merged.id;
b.parentId = merged.id;
clusters.Add(merged.id, merged);
//Update the active cluster set
activeClusterIds.Remove(a.id);
activeClusterIds.Remove(b.id);
activeClusterIds.Add(merged.id);
double totalCount = a.count + b.count;
//Update the distances, based on old distances
foreach (int i in merged.neighbors)
{
//Debug.Assert(i != merged.id && activeClusterIds.Contains(i));
//TODO: Ward's method with minimum variance
//For now, just use the dist between the centroids
PixelCluster c = clusters[i];
double newDist = merged.lab.SqDist(c.lab);
//Add in Ward's variance (variation in Color Segmentation using Region Merging)
//http://www.mathworks.com/help/toolbox/stats/linkage.html
newDist = newDist * Math.Sqrt(2 * a.count * b.count / (a.count + b.count));
if (c.id < merged.id)
{
pq.Enqueue(new Tuple <int, int>(c.id, merged.id), -1 * newDist);
}
else
{
pq.Enqueue(new Tuple <int, int>(merged.id, c.id), -1 * newDist);
}
}
//Remove the old clusters
foreach (int i in a.neighbors)
{
if (i > a.id)
{
pq.Remove(new Tuple <int, int>(a.id, i));
}
else
{
pq.Remove(new Tuple <int, int>(i, a.id));
}
}
foreach (int i in b.neighbors)
{
if (i > b.id)
{
pq.Remove(new Tuple <int, int>(b.id, i));
}
else
{
pq.Remove(new Tuple <int, int>(i, b.id));
}
}
//Repeat until termination criteria
if (activeClusterIds.Count() % 1000 == 0)
{
//write to file
log.WriteLine("Merge loop: " + timer.ElapsedMilliseconds / 1000.0 + " # Clusters: " + activeClusterIds.Count() + " pqCount: " + pq.Count + " merged # neighbors: " + merged.neighbors.Count);
log.Flush();
timer.Restart();
}
}
rootIds = activeClusterIds;
timer.Stop();
log.WriteLine("End: " + timer.ElapsedMilliseconds / 1000.0 + " # Clusters: " + activeClusterIds.Count() + " pqCount: " + pq.Count);
log.WriteLine("End Time: " + DateTime.Now.ToString());
log.Flush();
log.Close();
}
public void ClusterColors(List <CIELAB> colors, int width, int height)
{
//Bin the colors
int minRegions = 5;
double maxDist = 10 * 10;
SortedSet <int> activeClusterIds = new SortedSet <int>();
String logFile = "log-colorspace.txt";
StreamWriter log = File.AppendText(logFile);
log.WriteLine("\n\tCluster Color Space " + DateTime.Now.ToString());
log.Flush();
//the smaller id comes first in the dictionary for pairwise distances
PriorityQueue <Tuple <int, int>, double> pq = new PriorityQueue <Tuple <int, int>, double>();
clusters = new Dictionary <int, PixelCluster>();
int counter = 0;
foreach (CIELAB color in colors)
{
//bin it into one of the clusters
//index is a first, then b, then L
int id = GetBinId(color);
if (id > counter)
{
counter = id;
}
if (!clusters.ContainsKey(id))
{
clusters.Add(id, new PixelCluster(id, color));
}
else
{
clusters[id].lab = (clusters[id].lab * clusters[id].count + color) / (clusters[id].count + 1);
clusters[id].count++;
}
}
counter++;
activeClusterIds = new SortedSet <int>(clusters.Keys);
List <int> ids = activeClusterIds.ToList <int>();
for (int i = 0; i < ids.Count(); i++)
{
PixelCluster a = clusters[ids[i]];
//calculate distances to neighbors larger than current id
for (int j = i + 1; j < ids.Count(); j++)
{
PixelCluster b = clusters[ids[j]];
double newDist = a.lab.SqDist(b.lab);
//newDist = newDist * Math.Sqrt(2 * a.count * b.count / (a.count + b.count));
pq.Enqueue(new Tuple <int, int>(a.id, b.id), -1 * newDist);
}
}
Stopwatch timer = new Stopwatch();
timer.Start();
while (activeClusterIds.Count > minRegions)
{
//Find the pair with the smallest distance
KeyValuePair <Tuple <int, int>, double> result = BestPair(pq, activeClusterIds);
Tuple <int, int> pair = result.Key;
double bestDist = -1 * result.Value;
Console.WriteLine("num clusters: " + activeClusterIds.Count());
if (bestDist > maxDist)
{
break;
}
PixelCluster a = clusters[pair.Item1];
PixelCluster b = clusters[pair.Item2];
//Create a new cluster with unique id, don't care about neighbors
PixelCluster merged = new PixelCluster();
merged.id = counter++;
merged.lab = (a.lab * a.count + b.lab * b.count) / (a.count + b.count);
merged.count = a.count + b.count;
merged.children = new int[] { a.id, b.id };
merged.parentId = merged.id;
a.parentId = merged.id;
b.parentId = merged.id;
clusters.Add(merged.id, merged);
//Update the active cluster set
activeClusterIds.Remove(a.id);
activeClusterIds.Remove(b.id);
activeClusterIds.Add(merged.id);
double totalCount = a.count + b.count;
//Update the distances, based on old distances
foreach (int i in activeClusterIds)
{
//Debug.Assert(i != merged.id && activeClusterIds.Contains(i));
//TODO: Ward's method with minimum variance
//For now, just use the dist between the centroids
if (i == merged.id)
{
continue;
}
PixelCluster c = clusters[i];
double newDist = merged.lab.SqDist(c.lab);
//Add in Ward's variance (variation in Color Segmentation using Region Merging)
//http://www.mathworks.com/help/toolbox/stats/linkage.html
//newDist = newDist * Math.Sqrt(2 * a.count * b.count / (a.count + b.count));
if (c.id < merged.id)
{
pq.Enqueue(new Tuple <int, int>(c.id, merged.id), -1 * newDist);
}
else
{
pq.Enqueue(new Tuple <int, int>(merged.id, c.id), -1 * newDist);
}
}
//Remove the old clusters
foreach (int i in a.neighbors)
{
if (i > a.id)
{
pq.Remove(new Tuple <int, int>(a.id, i));
}
else
{
pq.Remove(new Tuple <int, int>(i, a.id));
}
}
foreach (int i in b.neighbors)
{
if (i > b.id)
{
pq.Remove(new Tuple <int, int>(b.id, i));
}
else
{
pq.Remove(new Tuple <int, int>(i, b.id));
}
}
//Repeat until termination criteria
if (activeClusterIds.Count() % 1000 == 0)
{
//write to file
log.WriteLine("Merge loop: " + timer.ElapsedMilliseconds / 1000.0 + " # Clusters: " + activeClusterIds.Count() + " pqCount: " + pq.Count + " merged # neighbors: " + merged.neighbors.Count);
log.Flush();
timer.Restart();
}
}
rootIds = activeClusterIds;
timer.Stop();
log.WriteLine("End: " + timer.ElapsedMilliseconds / 1000.0 + " # Clusters: " + activeClusterIds.Count() + " pqCount: " + pq.Count);
log.WriteLine("End Time: " + DateTime.Now.ToString());
log.Flush();
log.Close();
}
/**
* Now the Agglomerative Clustering. May want to pass in additional parameters, like the termination
* criteria and parameters.
* Assumes list of colors are in row-order
**/
public void Cluster(List<CIELAB> colors, int width, int height)
{
double maxDist = 50*10;
SortedSet<int> activeClusterIds = new SortedSet<int>();
String logFile = "log.txt";
StreamWriter log = File.AppendText(logFile);
log.WriteLine("\n\tCluster Spatial Run " + DateTime.Now.ToString());
log.Flush();
//the smaller id comes first in the dictionary for pairwise distances
PriorityQueue<Tuple<int, int>, double> pq = new PriorityQueue<Tuple<int, int>, double>();
clusters = new Dictionary<int, PixelCluster>();
int counter = 0;
//Initialize the clusters in row-order
for (int j = 0; j < height; j++)
{
for (int i = 0; i < width; i++)
{
activeClusterIds.Add(counter);
PixelCluster p = new PixelCluster(counter, colors[width * j + i]);
counter++;
//Initialize the 4-neighbors
if (i > 0)
p.neighbors.Add(ToIndex(i - 1, j, width));
if (j > 0)
p.neighbors.Add(ToIndex(i, j - 1, width));
if (i < width - 1)
p.neighbors.Add(ToIndex(i + 1, j, width));
if (j < height - 1)
p.neighbors.Add(ToIndex(i, j + 1, width));
clusters.Add(p.id, p);
}
}
foreach (int i in activeClusterIds)
{
//calculate distances to neighbors larger than current id
SortedSet<int> neighbors = Simplify(clusters[i].neighbors);
foreach (int j in neighbors)
{
if (i < j)
{
pq.Enqueue(new Tuple<int, int>(i, j), -1*clusters[i].lab.SqDist(clusters[j].lab));
}
}
}
Stopwatch timer = new Stopwatch();
timer.Start();
while (activeClusterIds.Count > 1)
{
//Find the pair with the smallest distance
KeyValuePair<Tuple<int, int>, double> result = BestPair(pq, activeClusterIds);
Tuple<int, int> pair = result.Key;
double bestDist = -1*result.Value;
Console.WriteLine("num clusters: " + activeClusterIds.Count());
if (bestDist > maxDist)
break;
PixelCluster a = clusters[pair.Item1];
PixelCluster b = clusters[pair.Item2];
//Create a new cluster with unique id
PixelCluster merged = new PixelCluster();
merged.id = counter++;
merged.lab = (a.lab * a.count + b.lab * b.count) / (a.count + b.count);
merged.count = a.count + b.count;
merged.children = new int[] { a.id, b.id };
merged.neighbors = MergeNeighbors(a.id, b.id);
merged.parentId = merged.id;
a.parentId = merged.id;
b.parentId = merged.id;
clusters.Add(merged.id, merged);
//Update the active cluster set
activeClusterIds.Remove(a.id);
activeClusterIds.Remove(b.id);
activeClusterIds.Add(merged.id);
double totalCount = a.count + b.count;
//Update the distances, based on old distances
foreach (int i in merged.neighbors)
{
//Debug.Assert(i != merged.id && activeClusterIds.Contains(i));
//TODO: Ward's method with minimum variance
//For now, just use the dist between the centroids
PixelCluster c = clusters[i];
double newDist = merged.lab.SqDist(c.lab);
//Add in Ward's variance (variation in Color Segmentation using Region Merging)
//http://www.mathworks.com/help/toolbox/stats/linkage.html
newDist = newDist * Math.Sqrt(2 * a.count * b.count / (a.count + b.count));
if (c.id < merged.id)
pq.Enqueue(new Tuple<int, int>(c.id, merged.id), -1 * newDist);
else
pq.Enqueue(new Tuple<int, int>(merged.id, c.id), -1 * newDist);
}
//Remove the old clusters
foreach (int i in a.neighbors)
{
if (i > a.id)
pq.Remove(new Tuple<int, int>(a.id, i));
else
pq.Remove(new Tuple<int, int>(i, a.id));
}
foreach (int i in b.neighbors)
{
if (i > b.id)
pq.Remove(new Tuple<int, int>(b.id, i));
else
pq.Remove(new Tuple<int, int>(i, b.id));
}
//Repeat until termination criteria
if (activeClusterIds.Count() % 1000 == 0)
{
//write to file
log.WriteLine("Merge loop: " + timer.ElapsedMilliseconds/1000.0 + " # Clusters: " + activeClusterIds.Count() + " pqCount: " + pq.Count + " merged # neighbors: " + merged.neighbors.Count );
log.Flush();
timer.Restart();
}
}
rootIds = activeClusterIds;
timer.Stop();
log.WriteLine("End: " + timer.ElapsedMilliseconds/1000.0 + " # Clusters: " + activeClusterIds.Count() + " pqCount: " + pq.Count);
log.WriteLine("End Time: " + DateTime.Now.ToString());
log.Flush();
log.Close();
}
//Cluster the final clusters into color space
public void ClusterColorSpace()
{
double maxDist = 20*20;
int minRegions = 5;
SortedSet<int> activeClusterIds = new SortedSet<int>(rootIds);
String logFile = "colorlog.txt";
StreamWriter log = File.AppendText(logFile);
log.WriteLine("\n\tCluster ColorSpace Run " + DateTime.Now.ToString());
log.Flush();
//the smaller id comes first in the dictionary for pairwise distances
PriorityQueue<Tuple<int, int>, double> pq = new PriorityQueue<Tuple<int, int>, double>();
int counter = activeClusterIds.Last()+1;
int[] ids = activeClusterIds.ToArray<int>();
//Calculate the initial distances
for (int i = 0; i < ids.Count(); i++)
{
for (int j = i+1; j < ids.Count(); j++)
{
//log.WriteLine(ids[i] + ", " + ids[j] + " dist " + -1 * clusters[ids[i]].lab.SqDist(clusters[ids[j]].lab));
//log.Flush();
//pq.Enqueue(new Tuple<int, int>(ids[i], ids[j]), -1 * clusters[ids[i]].lab.SqDist(clusters[ids[j]].lab));
PixelCluster a = clusters[ids[i]];
PixelCluster b = clusters[ids[j]];
double newDist = a.lab.SqDist(b.lab);
//Add in Ward's variance (variation in Color Segmentation using Region Merging)
//http://www.mathworks.com/help/toolbox/stats/linkage.html
//newDist = newDist * Math.Sqrt(2 * a.count * b.count / (a.count + b.count));
pq.Enqueue(new Tuple<int, int>(ids[i], ids[j]), -1 * newDist);
}
}
Stopwatch timer = new Stopwatch();
timer.Start();
while (activeClusterIds.Count > minRegions)
{
//Find the pair with the smallest distance
KeyValuePair<Tuple<int, int>, double> result = BestPair(pq, activeClusterIds);
Tuple<int, int> pair = result.Key;
double bestDist = -1 * result.Value;
Console.WriteLine("num clusters: " + activeClusterIds.Count());
if (bestDist > maxDist)
break;
PixelCluster a = clusters[pair.Item1];
PixelCluster b = clusters[pair.Item2];
//Create a new cluster with unique id, we don't care about the neighbors
PixelCluster merged = new PixelCluster();
merged.id = counter++;
merged.lab = (a.lab * a.count + b.lab * b.count) / (a.count + b.count);
merged.count = a.count + b.count;
merged.children = new int[] { a.id, b.id };
merged.parentId = merged.id;
a.parentId = merged.id;
b.parentId = merged.id;
clusters.Add(merged.id, merged);
//Update the active cluster set
activeClusterIds.Remove(a.id);
activeClusterIds.Remove(b.id);
activeClusterIds.Add(merged.id);
double totalCount = a.count + b.count;
//Update the distances, based on old distances
foreach (int i in activeClusterIds)
{
if (i == merged.id)
continue;
//TODO: Ward's method with minimum variance
//For now, just use the dist between the centroids
PixelCluster c = clusters[i];
double newDist = merged.lab.SqDist(c.lab);
//Add in Ward's variance (variation in Color Segmentation using Region Merging)
//http://www.mathworks.com/help/toolbox/stats/linkage.html
//newDist = newDist * Math.Sqrt(2*a.count * b.count / (a.count + b.count));
if (c.id < merged.id)
pq.Enqueue(new Tuple<int, int>(c.id, merged.id), -1 * newDist);
else
pq.Enqueue(new Tuple<int, int>(merged.id, c.id), -1 * newDist);
}
//Remove the old clusters
foreach (int i in activeClusterIds)
{
if (i > a.id)
pq.Remove(new Tuple<int, int>(a.id, i));
else
pq.Remove(new Tuple<int, int>(i, a.id));
}
foreach (int i in activeClusterIds)
{
if (i > b.id)
pq.Remove(new Tuple<int, int>(b.id, i));
else
pq.Remove(new Tuple<int, int>(i, b.id));
}
//Repeat until termination criteria
if (activeClusterIds.Count() % 1000 == 0)
{
//write to file
log.WriteLine("Merge loop: " + timer.ElapsedMilliseconds / 1000.0 + " # Clusters: " + activeClusterIds.Count() + " pqCount: " + pq.Count + " merged # neighbors: " + merged.neighbors.Count);
log.Flush();
timer.Restart();
}
}
rootIds = activeClusterIds;
timer.Stop();
log.WriteLine("End: " + timer.ElapsedMilliseconds / 1000.0 + " # Clusters: " + activeClusterIds.Count() + " pqCount: " + pq.Count);
log.WriteLine("End Time: " + DateTime.Now.ToString());
log.Flush();
log.Close();
}
public void ClusterColors(List<CIELAB> colors, int width, int height)
{
//Bin the colors
int minRegions = 5;
double maxDist = 10*10;
SortedSet<int> activeClusterIds = new SortedSet<int>();
String logFile = "log-colorspace.txt";
StreamWriter log = File.AppendText(logFile);
log.WriteLine("\n\tCluster Color Space " + DateTime.Now.ToString());
log.Flush();
//the smaller id comes first in the dictionary for pairwise distances
PriorityQueue<Tuple<int, int>, double> pq = new PriorityQueue<Tuple<int, int>, double>();
clusters = new Dictionary<int, PixelCluster>();
int counter = 0;
foreach (CIELAB color in colors)
{
//bin it into one of the clusters
//index is a first, then b, then L
int id = GetBinId(color);
if (id > counter)
counter = id;
if (!clusters.ContainsKey(id))
{
clusters.Add(id, new PixelCluster(id, color));
}
else
{
clusters[id].lab = (clusters[id].lab * clusters[id].count + color) / (clusters[id].count + 1);
clusters[id].count++;
}
}
counter++;
activeClusterIds = new SortedSet<int>(clusters.Keys);
List<int> ids = activeClusterIds.ToList<int>();
for (int i=0; i<ids.Count(); i++)
{
PixelCluster a = clusters[ids[i]];
//calculate distances to neighbors larger than current id
for (int j=i+1; j<ids.Count(); j++)
{
PixelCluster b = clusters[ids[j]];
double newDist = a.lab.SqDist(b.lab);
//newDist = newDist * Math.Sqrt(2 * a.count * b.count / (a.count + b.count));
pq.Enqueue(new Tuple<int, int>(a.id, b.id), -1*newDist);
}
}
Stopwatch timer = new Stopwatch();
timer.Start();
while (activeClusterIds.Count > minRegions)
{
//Find the pair with the smallest distance
KeyValuePair<Tuple<int, int>, double> result = BestPair(pq, activeClusterIds);
Tuple<int, int> pair = result.Key;
double bestDist = -1 * result.Value;
Console.WriteLine("num clusters: " + activeClusterIds.Count());
if (bestDist > maxDist)
break;
PixelCluster a = clusters[pair.Item1];
PixelCluster b = clusters[pair.Item2];
//Create a new cluster with unique id, don't care about neighbors
PixelCluster merged = new PixelCluster();
merged.id = counter++;
merged.lab = (a.lab * a.count + b.lab * b.count) / (a.count + b.count);
merged.count = a.count + b.count;
merged.children = new int[] { a.id, b.id };
merged.parentId = merged.id;
a.parentId = merged.id;
b.parentId = merged.id;
clusters.Add(merged.id, merged);
//Update the active cluster set
activeClusterIds.Remove(a.id);
activeClusterIds.Remove(b.id);
activeClusterIds.Add(merged.id);
double totalCount = a.count + b.count;
//Update the distances, based on old distances
foreach (int i in activeClusterIds)
{
//Debug.Assert(i != merged.id && activeClusterIds.Contains(i));
//TODO: Ward's method with minimum variance
//For now, just use the dist between the centroids
if (i == merged.id)
continue;
PixelCluster c = clusters[i];
double newDist = merged.lab.SqDist(c.lab);
//Add in Ward's variance (variation in Color Segmentation using Region Merging)
//http://www.mathworks.com/help/toolbox/stats/linkage.html
//newDist = newDist * Math.Sqrt(2 * a.count * b.count / (a.count + b.count));
if (c.id < merged.id)
pq.Enqueue(new Tuple<int, int>(c.id, merged.id), -1 * newDist);
else
pq.Enqueue(new Tuple<int, int>(merged.id, c.id), -1 * newDist);
}
//Remove the old clusters
foreach (int i in a.neighbors)
{
if (i > a.id)
pq.Remove(new Tuple<int, int>(a.id, i));
else
pq.Remove(new Tuple<int, int>(i, a.id));
}
foreach (int i in b.neighbors)
{
if (i > b.id)
pq.Remove(new Tuple<int, int>(b.id, i));
else
pq.Remove(new Tuple<int, int>(i, b.id));
}
//Repeat until termination criteria
if (activeClusterIds.Count() % 1000 == 0)
{
//write to file
log.WriteLine("Merge loop: " + timer.ElapsedMilliseconds / 1000.0 + " # Clusters: " + activeClusterIds.Count() + " pqCount: " + pq.Count + " merged # neighbors: " + merged.neighbors.Count);
log.Flush();
timer.Restart();
}
}
rootIds = activeClusterIds;
timer.Stop();
log.WriteLine("End: " + timer.ElapsedMilliseconds / 1000.0 + " # Clusters: " + activeClusterIds.Count() + " pqCount: " + pq.Count);
log.WriteLine("End Time: " + DateTime.Now.ToString());
log.Flush();
log.Close();
}
