public static List <BoundingBoxGroup> GreedyMeanHierarchicalMergeByPixelDeviation(List <BoundingBox> originalBoundingBoxes, List <string> originalIdentifiers, double deviationToleranceThreshold)
{
List <BoundingBoxGroup> ret = new List <BoundingBoxGroup>();
//initialize by creating one group per bounding box
for (int i = 0; i < originalBoundingBoxes.Count; i++)
{
BoundingBox b = originalBoundingBoxes[i];
BoundingBoxGroup bgroup = new BoundingBoxGroup();
bgroup.mergedBoundingBox = new BoundingBox(b.tlx, b.tly, b.brx, b.bry);
bgroup.boundingBoxList.Add(b);
bgroup.identifiers.Add(originalIdentifiers[i]);
ret.Add(bgroup);
}
bool changed = false;
do
{
changed = false;
//find the closest mergable bouding box group pair and merge by averaging
int index1 = -1;
int index2 = -1;
//double bestSimilarity = 0;
double bestDeviation = 10000000000;
BoundingBox bestMergedBoundingBox = null;
for (int i = 0; i < ret.Count - 1; i++)
{
for (int j = i + 1; j < ret.Count; j++)
{
//compute the merged bouding box
BoundingBox meanB = computeMeanBoudingBoxFromTwoGroups(ret[i].boundingBoxList, ret[j].boundingBoxList);
double deviation1 = meanB.ComputeMaxDeviationMetric(ret[i].mergedBoundingBox);
double deviation2 = meanB.ComputeMaxDeviationMetric(ret[j].mergedBoundingBox);
double maxDeviation = Math.Max(deviation1, deviation2);
if (maxDeviation <= deviationToleranceThreshold)
{
if (maxDeviation < bestDeviation)
{
bestDeviation = maxDeviation;
index1 = i;
index2 = j;
bestMergedBoundingBox = meanB;
changed = true;
}
}
}
}
if (changed) //there is something worth merging
{
//merge 2 into 1
for (int i = 0; i < ret[index2].boundingBoxList.Count; i++)
{
ret[index1].boundingBoxList.Add(ret[index2].boundingBoxList[i]);
ret[index1].identifiers.Add(ret[index2].identifiers[i]);
}
ret[index1].mergedBoundingBox = bestMergedBoundingBox;
//remove 2
ret.RemoveAt(index2);
}
if (ret.Count == 1)
{
break;
}
} while (changed);
return(ret);
}
