public double SegmentImageWithShapeTerms(
Func <int, int, ObjectBackgroundTerm> shapeTermCalculator)
{
// Calculate shape terms, check for changes)
for (int x = 0; x < this.lastUnaryTerms.Width; ++x)
{
for (int y = 0; y < this.lastUnaryTerms.Height; ++y)
{
ObjectBackgroundTerm shapeTerms = shapeTermCalculator(x, y);
if (firstTime || shapeTerms != this.lastShapeTerms[x, y])
{
double objectTermNew = this.UnaryTermScaleCoeff * (this.colorTerms[x, y].ObjectTerm * this.ObjectColorUnaryTermWeight + shapeTerms.ObjectTerm * this.ObjectShapeUnaryTermWeight);
double backgroundTermNew = this.UnaryTermScaleCoeff * (this.colorTerms[x, y].BackgroundTerm * this.BackgroundColorUnaryTermWeight + shapeTerms.BackgroundTerm * this.BackgroundShapeUnaryTermWeight);
Debug.Assert(!Double.IsInfinity(objectTermNew) && !Double.IsNaN(objectTermNew));
Debug.Assert(!Double.IsInfinity(backgroundTermNew) && !Double.IsNaN(backgroundTermNew));
if (firstTime)
{
this.graphCutCalculator.SetTerminalWeights(x, y, backgroundTermNew, objectTermNew);
}
else
{
this.graphCutCalculator.UpdateTerminalWeights(
x, y, this.lastUnaryTerms[x, y].BackgroundTerm, this.lastUnaryTerms[x, y].ObjectTerm, backgroundTermNew, objectTermNew);
}
this.lastShapeTerms[x, y] = shapeTerms;
this.lastUnaryTerms[x, y] = new ObjectBackgroundTerm(objectTermNew, backgroundTermNew);
}
}
}
// Actually segment image
double graphCutEnergy = this.graphCutCalculator.Calculate();
bool wasFirstTime = this.firstTime;
this.firstTime = false;
// Fill segmentation mask
for (int x = 0; x < this.lastSegmentationMask.Width; ++x)
{
for (int y = 0; y < this.lastSegmentationMask.Height; ++y)
{
bool isObject = this.graphCutCalculator.BelongsToSource(x, y);
this.lastSegmentationMask[x, y] = isObject;
}
}
// Compute energy
ImageSegmentationFeatures features = this.ExtractSegmentationFeaturesForMask(this.lastSegmentationMask);
double energy = features.FeatureSum;
// Sanity check: energies should be the same if graph cut calculator is "fresh"
Trace.Assert(!wasFirstTime || Math.Abs(graphCutEnergy - energy) < 1e-6);
return(energy);
}
public void CalculateShapeTerms(ShapeModel model, ShapeConstraints constraintsSet, Image2D <ObjectBackgroundTerm> result)
{
if (model == null)
{
throw new ArgumentNullException("model");
}
if (constraintsSet == null)
{
throw new ArgumentNullException("constraintsSet");
}
if (result == null)
{
throw new ArgumentNullException("result");
}
if (model.Structure != constraintsSet.ShapeStructure)
{
throw new ArgumentException("Shape model and shape constraints correspond to different shape structures.");
}
if (model != this.shapeModel || result.Rectangle.Size != this.imageSize)
{
this.SetTarget(model, result.Rectangle.Size);
}
for (int x = 0; x < imageSize.Width; ++x)
{
for (int y = 0; y < imageSize.Height; ++y)
{
result[x, y] = new ObjectBackgroundTerm(Double.PositiveInfinity, 0);
}
}
for (int edgeIndex = 0; edgeIndex < this.shapeModel.Structure.Edges.Count; ++edgeIndex)
{
ShapeEdge edge = this.shapeModel.Structure.Edges[edgeIndex];
VertexConstraints vertexConstraints1 = constraintsSet.VertexConstraints[edge.Index1];
VertexConstraints vertexConstraints2 = constraintsSet.VertexConstraints[edge.Index2];
EdgeConstraints edgeConstraints = constraintsSet.EdgeConstraints[edgeIndex];
Image2D <ObjectBackgroundTerm> edgeTerms;
EdgeDescription edgeDescription = new EdgeDescription(
vertexConstraints1, vertexConstraints2, edgeConstraints);
if (!this.cachedEdgeTerms.TryGetValue(edgeDescription, out edgeTerms))
{
edgeTerms = this.AllocateImage();
this.cachedEdgeTerms.Add(edgeDescription, edgeTerms);
Polygon convexHull = constraintsSet.GetConvexHullForVertexPair(edge.Index1, edge.Index2);
Parallel.For(
0,
imageSize.Width,
x =>
{
for (int y = 0; y < imageSize.Height; ++y)
{
Vector pointAsVec = new Vector(x, y);
double minDistanceSqr, maxDistanceSqr;
MinMaxDistanceForEdge(
pointAsVec,
convexHull,
vertexConstraints1,
vertexConstraints2,
out minDistanceSqr,
out maxDistanceSqr);
edgeTerms[x, y] = new ObjectBackgroundTerm(
this.shapeModel.CalculateObjectPenaltyForEdge(
minDistanceSqr, edgeConstraints.MaxWidth),
this.shapeModel.CalculateBackgroundPenaltyForEdge(
maxDistanceSqr, edgeConstraints.MinWidth));
}
});
}
for (int x = 0; x < imageSize.Width; ++x)
{
for (int y = 0; y < imageSize.Height; ++y)
{
result[x, y] = new ObjectBackgroundTerm(
Math.Min(result[x, y].ObjectTerm, edgeTerms[x, y].ObjectTerm),
Math.Max(result[x, y].BackgroundTerm, edgeTerms[x, y].BackgroundTerm));
}
}
}
}
