private static double CalculateMinUnaryEdgeEnergy(int edgeIndex, ShapeModel model, ShapeConstraints shapeConstraints, double edgeLength)
{
double bestWidth = edgeLength * model.GetEdgeParams(edgeIndex).WidthToEdgeLengthRatio;
EdgeConstraints edgeConstraints = shapeConstraints.EdgeConstraints[edgeIndex];
bestWidth = MathHelper.Trunc(bestWidth, edgeConstraints.MinWidth, edgeConstraints.MaxWidth);
return(model.CalculateEdgeWidthEnergyTerm(edgeIndex, bestWidth, edgeLength));
}
private void SetTarget(ShapeModel newShapeModel, Size newImageSize)
{
if (newShapeModel.Structure.Edges.Count > CacheCapacity)
{
throw new InvalidOperationException("Edge count is bigger than cache size. Such shape models are not currently supported.");
}
this.freeTermImages = new LinkedList <Image2D <ObjectBackgroundTerm> >();
this.cachedEdgeTerms = new LruCache <EdgeDescription, Image2D <ObjectBackgroundTerm> >(CacheCapacity);
this.cachedEdgeTerms.CacheItemDiscarded += (sender, args) => this.DeallocateImage(args.DiscardedValue);
this.shapeModel = newShapeModel;
this.imageSize = newImageSize;
}
private static double CalculateSingleEdgeLowerBound(
ShapeModel model, ShapeConstraints shapeConstraints, IList<ILengthAngleConstraints> lengthAngleConstraints)
{
// TODO: support models with multiple edges but without pairwise constraints
Debug.Assert(model.Structure.Edges.Count == 1);
Debug.Assert(lengthAngleConstraints.Count == 1);
double result;
// Calculate best possible edge width penalty
EdgeConstraints edgeConstraints = shapeConstraints.EdgeConstraints[0];
ShapeEdgeParams edgeParams = model.GetEdgeParams(0);
Range lengthBoundary = lengthAngleConstraints[0].LengthBoundary;
Range scaledLengthRange = new Range(lengthBoundary.Left * edgeParams.WidthToEdgeLengthRatio, lengthBoundary.Right * edgeParams.WidthToEdgeLengthRatio);
Range widthRange = new Range(edgeConstraints.MinWidth, edgeConstraints.MaxWidth);
if (scaledLengthRange.IntersectsWith(widthRange))
result = 0;
else
{
result = model.CalculateEdgeWidthEnergyTerm(0, widthRange.Right, lengthBoundary.Left);
result = Math.Min(result, model.CalculateEdgeWidthEnergyTerm(0, widthRange.Left, lengthBoundary.Right));
}
return result;
}
public double CalculateLowerBound(Size imageSize, ShapeModel model, ShapeConstraints shapeConstraints)
{
if (model == null)
throw new ArgumentNullException("model");
if (shapeConstraints == null)
throw new ArgumentNullException("shapeConstraints");
if (model.Structure != shapeConstraints.ShapeStructure)
throw new ArgumentException("Shape model and shape constraints correspond to different shape structures.");
List<ILengthAngleConstraints> lengthAngleConstraints = CalculateLengthAngleConstraints(shapeConstraints);
if (model.ConstrainedEdgePairs.Count == 0)
{
double lowerBound = CalculateSingleEdgeLowerBound(model, shapeConstraints, lengthAngleConstraints);
Debug.Assert(lowerBound >= 0);
return lowerBound;
}
// Determine max (scaled) length possible
double maxRatio1 = (from edgePair in model.ConstrainedEdgePairs
select model.GetEdgePairParams(edgePair.Item1, edgePair.Item2).MeanLengthRatio).Max();
double maxRatio2 = (from edgePair in model.ConstrainedEdgePairs
select 1.0 / model.GetEdgePairParams(edgePair.Item1, edgePair.Item2).MeanLengthRatio).Max();
double maxRatio = Math.Max(maxRatio1, maxRatio2);
double maxEdgeLength = (new Vector(imageSize.Width, imageSize.Height)).Length;
double maxScaledLength = maxEdgeLength * maxRatio;
if (maxScaledLength != this.currentMaxScaledLength)
{
this.currentMaxScaledLength = maxScaledLength;
this.transformPool.Clear();
}
this.FreeAllDistanceTransforms();
// Calculate distance transforms for all the child edges
List<GeneralizedDistanceTransform2D> childTransforms = new List<GeneralizedDistanceTransform2D>();
foreach (int edgeIndex in model.IterateNeighboringEdgeIndices(model.RootEdgeIndex))
childTransforms.Add(CalculateMinEnergiesForAllParentEdges(model, shapeConstraints, model.RootEdgeIndex, edgeIndex, lengthAngleConstraints));
// Find best overall solution
double minEnergySum = Double.PositiveInfinity;
GeneralizedDistanceTransform2D transform = childTransforms[0];
foreach (int lengthGridIndex in transform.EnumerateInterestGridIndicesX())
{
double length = transform.GridIndexToCoordX(lengthGridIndex);
double minPairwiseEnergy = Double.PositiveInfinity;
foreach (int angleGridIndex in transform.EnumerateInterestGridIndicesY())
{
double angle = transform.GridIndexToCoordY(angleGridIndex);
const double eps = 1e-8;
if (angle > Math.PI + eps || angle < -Math.PI - eps)
continue; // Consider only natural angle representations here
minPairwiseEnergy = Math.Min(minPairwiseEnergy, CalculateMinPairwiseEdgeEnergy(length, angle, childTransforms));
}
double unaryEdgeEnergy = CalculateMinUnaryEdgeEnergy(model.RootEdgeIndex, model, shapeConstraints, length);
double rootEdgeEnergy = model.CalculateRootEdgeEnergyTerm(length);
minEnergySum = Math.Min(minEnergySum, minPairwiseEnergy + unaryEdgeEnergy + rootEdgeEnergy);
}
Debug.Assert(minEnergySum >= 0);
return minEnergySum;
}
private GeneralizedDistanceTransform2D CalculateMinEnergiesForAllParentEdges(
ShapeModel model,
ShapeConstraints shapeConstraints,
int parentEdgeIndex,
int currentEdgeIndex,
IList<ILengthAngleConstraints> lengthAngleConstraints)
{
// Calculate child transforms
List<GeneralizedDistanceTransform2D> childDistanceTransforms = new List<GeneralizedDistanceTransform2D>();
foreach (int neighborEdgeIndex in model.IterateNeighboringEdgeIndices(currentEdgeIndex))
{
// Iterate only through children
if (neighborEdgeIndex == parentEdgeIndex)
continue;
GeneralizedDistanceTransform2D childTransform = CalculateMinEnergiesForAllParentEdges(
model, shapeConstraints, currentEdgeIndex, neighborEdgeIndex, lengthAngleConstraints);
Debug.Assert(childTransform.IsComputed);
childDistanceTransforms.Add(childTransform);
}
ShapeEdgePairParams pairParams = model.GetEdgePairParams(parentEdgeIndex, currentEdgeIndex);
GeneralizedDistanceTransform2D transform = this.AllocateDistanceTransform();
SetupTransformFinitePenaltyRanges(transform, pairParams, lengthAngleConstraints[currentEdgeIndex]);
SetupTransformInterestRanges(transform, lengthAngleConstraints[parentEdgeIndex]);
Func<double, double, double> penaltyFunction =
(scaledLength, shiftedAngle) =>
{
double length = scaledLength / pairParams.MeanLengthRatio;
double angle = shiftedAngle + pairParams.MeanAngle;
double lengthTolerance = transform.GridStepSizeX / pairParams.MeanLengthRatio;
double angleTolerance = transform.GridStepSizeY;
if (!lengthAngleConstraints[currentEdgeIndex].InRange(length, lengthTolerance, angle, angleTolerance))
return 1e+20;
double penalty =
CalculateMinUnaryEdgeEnergy(currentEdgeIndex, model, shapeConstraints, length) +
CalculateMinPairwiseEdgeEnergy(length, angle, childDistanceTransforms);
return penalty;
};
transform.Compute(
0.5 / MathHelper.Sqr(pairParams.LengthDiffDeviation),
0.5 / MathHelper.Sqr(pairParams.AngleDeviation),
penaltyFunction);
return transform;
}
private static double CalculateMinUnaryEdgeEnergy(int edgeIndex, ShapeModel model, ShapeConstraints shapeConstraints, double edgeLength)
{
double bestWidth = edgeLength * model.GetEdgeParams(edgeIndex).WidthToEdgeLengthRatio;
EdgeConstraints edgeConstraints = shapeConstraints.EdgeConstraints[edgeIndex];
bestWidth = MathHelper.Trunc(bestWidth, edgeConstraints.MinWidth, edgeConstraints.MaxWidth);
return model.CalculateEdgeWidthEnergyTerm(edgeIndex, bestWidth, edgeLength);
}
public Shape MutateShape(Shape shape, ShapeModel shapeModel, Size imageSize, double normalizedTemperature)
{
if (shape == null)
{
throw new ArgumentNullException("shape");
}
if (shapeModel == null)
{
throw new ArgumentNullException("shapeModel");
}
double maxImageSideSize = Math.Max(imageSize.Width, imageSize.Height);
Shape mutatedShape;
double weightSum =
this.edgeWidthMutationWeight +
this.edgeLengthMutationWeight +
this.edgeAngleMutationWeight +
this.shapeTranslationWeight +
this.shapeScaleWeight;
if (weightSum <= 0)
{
throw new InvalidOperationException("At least one type of mutation should have non-zero probability weight.");
}
double rand = Random.Double(0, weightSum);
// Shape part mutation
if (rand < this.edgeWidthMutationWeight + this.edgeLengthMutationWeight + this.edgeAngleMutationWeight)
{
ShapeLengthAngleRepresentation representation = shape.GetLengthAngleRepresentation();
int randomEdge = Random.Int(shape.Structure.Edges.Count);
// Mutate edge width
if (rand < this.edgeWidthMutationWeight)
{
double widthShiftStdDev = maxImageSideSize * this.edgeWidthMutationPower * normalizedTemperature;
const double minWidth = 3;
double widthShift = Random.Normal(0, widthShiftStdDev, -shape.EdgeWidths[randomEdge] + minWidth);
representation.EdgeWidths[randomEdge] += widthShift;
}
// Mutate edge length
else if (rand < this.edgeWidthMutationWeight + this.edgeLengthMutationWeight)
{
double lengthShiftStdDev = maxImageSideSize * this.edgeLengthMutationPower * normalizedTemperature;
double lengthShift = Random.Normal(0, lengthShiftStdDev);
representation.EdgeLengths[randomEdge] += lengthShift;
}
// Mutate edge angle
else
{
double angleShiftStdDev = this.edgeAngleMutationPower * normalizedTemperature;
double angleShift = Random.Normal(0, angleShiftStdDev);
representation.EdgeAngles[randomEdge] += angleShift;
}
mutatedShape = shapeModel.BuildShapeFromLengthAngleRepresentation(representation);
}
// Whole shape mutation
else
{
rand -= this.edgeWidthMutationWeight + this.edgeLengthMutationWeight + this.edgeAngleMutationWeight;
mutatedShape = shape.Clone();
// Translate shape
if (rand < this.shapeTranslationWeight)
{
Vector maxTopLeftShift = new Vector(Double.NegativeInfinity, Double.NegativeInfinity);
Vector minBottomRightShift = new Vector(Double.PositiveInfinity, Double.PositiveInfinity);
for (int i = 0; i < mutatedShape.VertexPositions.Count; ++i)
{
maxTopLeftShift.X = Math.Max(maxTopLeftShift.X, -mutatedShape.VertexPositions[i].X);
maxTopLeftShift.Y = Math.Max(maxTopLeftShift.Y, -mutatedShape.VertexPositions[i].Y);
minBottomRightShift.X = Math.Min(minBottomRightShift.X, imageSize.Width - mutatedShape.VertexPositions[i].X);
minBottomRightShift.Y = Math.Min(minBottomRightShift.Y, imageSize.Height - mutatedShape.VertexPositions[i].Y);
}
double translationStdDev = maxImageSideSize * this.shapeTranslationPower * normalizedTemperature;
Vector shift = new Vector(Random.Normal(0, translationStdDev), Random.Normal(0, translationStdDev));
shift = MathHelper.Trunc(shift, maxTopLeftShift, minBottomRightShift);
for (int i = 0; i < mutatedShape.VertexPositions.Count; ++i)
{
mutatedShape.VertexPositions[i] += shift;
}
}
// Scale shape
else
{
Vector shapeCenter = shape.VertexPositions.Aggregate(Vector.Zero, (a, c) => a + c) / shape.VertexPositions.Count;
double scaleStdDev = this.shapeScalePower * normalizedTemperature;
const double minScale = 0.1;
double scale = Random.Normal(1.0, scaleStdDev, minScale);
for (int i = 0; i < mutatedShape.VertexPositions.Count; ++i)
{
mutatedShape.VertexPositions[i] = shapeCenter + scale * (mutatedShape.VertexPositions[i] - shapeCenter);
}
}
}
Debug.Assert(mutatedShape != null);
return(mutatedShape);
}
private void SetTarget(ShapeModel newShapeModel, Size newImageSize)
{
if (newShapeModel.Structure.Edges.Count > CacheCapacity)
throw new InvalidOperationException("Edge count is bigger than cache size. Such shape models are not currently supported.");
this.freeTermImages = new LinkedList<Image2D<ObjectBackgroundTerm>>();
this.cachedEdgeTerms = new LruCache<EdgeDescription, Image2D<ObjectBackgroundTerm>>(CacheCapacity);
this.cachedEdgeTerms.CacheItemDiscarded += (sender, args) => this.DeallocateImage(args.DiscardedValue);
this.shapeModel = newShapeModel;
this.imageSize = newImageSize;
}
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));
}
}
public Shape MutateShape(Shape shape, ShapeModel shapeModel, Size imageSize, double normalizedTemperature)
{
if (shape == null)
throw new ArgumentNullException("shape");
if (shapeModel == null)
throw new ArgumentNullException("shapeModel");
double maxImageSideSize = Math.Max(imageSize.Width, imageSize.Height);
Shape mutatedShape;
double weightSum =
this.edgeWidthMutationWeight +
this.edgeLengthMutationWeight +
this.edgeAngleMutationWeight +
this.shapeTranslationWeight +
this.shapeScaleWeight;
if (weightSum <= 0)
throw new InvalidOperationException("At least one type of mutation should have non-zero probability weight.");
double rand = Random.Double(0, weightSum);
// Shape part mutation
if (rand < this.edgeWidthMutationWeight + this.edgeLengthMutationWeight + this.edgeAngleMutationWeight)
{
ShapeLengthAngleRepresentation representation = shape.GetLengthAngleRepresentation();
int randomEdge = Random.Int(shape.Structure.Edges.Count);
// Mutate edge width
if (rand < this.edgeWidthMutationWeight)
{
double widthShiftStdDev = maxImageSideSize * this.edgeWidthMutationPower * normalizedTemperature;
const double minWidth = 3;
double widthShift = Random.Normal(0, widthShiftStdDev, -shape.EdgeWidths[randomEdge] + minWidth);
representation.EdgeWidths[randomEdge] += widthShift;
}
// Mutate edge length
else if (rand < this.edgeWidthMutationWeight + this.edgeLengthMutationWeight)
{
double lengthShiftStdDev = maxImageSideSize * this.edgeLengthMutationPower * normalizedTemperature;
double lengthShift = Random.Normal(0, lengthShiftStdDev);
representation.EdgeLengths[randomEdge] += lengthShift;
}
// Mutate edge angle
else
{
double angleShiftStdDev = this.edgeAngleMutationPower * normalizedTemperature;
double angleShift = Random.Normal(0, angleShiftStdDev);
representation.EdgeAngles[randomEdge] += angleShift;
}
mutatedShape = shapeModel.BuildShapeFromLengthAngleRepresentation(representation);
}
// Whole shape mutation
else
{
rand -= this.edgeWidthMutationWeight + this.edgeLengthMutationWeight + this.edgeAngleMutationWeight;
mutatedShape = shape.Clone();
// Translate shape
if (rand < this.shapeTranslationWeight)
{
Vector maxTopLeftShift = new Vector(Double.NegativeInfinity, Double.NegativeInfinity);
Vector minBottomRightShift = new Vector(Double.PositiveInfinity, Double.PositiveInfinity);
for (int i = 0; i < mutatedShape.VertexPositions.Count; ++i)
{
maxTopLeftShift.X = Math.Max(maxTopLeftShift.X, -mutatedShape.VertexPositions[i].X);
maxTopLeftShift.Y = Math.Max(maxTopLeftShift.Y, -mutatedShape.VertexPositions[i].Y);
minBottomRightShift.X = Math.Min(minBottomRightShift.X, imageSize.Width - mutatedShape.VertexPositions[i].X);
minBottomRightShift.Y = Math.Min(minBottomRightShift.Y, imageSize.Height - mutatedShape.VertexPositions[i].Y);
}
double translationStdDev = maxImageSideSize * this.shapeTranslationPower * normalizedTemperature;
Vector shift = new Vector(Random.Normal(0, translationStdDev), Random.Normal(0, translationStdDev));
shift = MathHelper.Trunc(shift, maxTopLeftShift, minBottomRightShift);
for (int i = 0; i < mutatedShape.VertexPositions.Count; ++i)
mutatedShape.VertexPositions[i] += shift;
}
// Scale shape
else
{
Vector shapeCenter = shape.VertexPositions.Aggregate(Vector.Zero, (a, c) => a + c) / shape.VertexPositions.Count;
double scaleStdDev = this.shapeScalePower * normalizedTemperature;
const double minScale = 0.1;
double scale = Random.Normal(1.0, scaleStdDev, minScale);
for (int i = 0; i < mutatedShape.VertexPositions.Count; ++i)
mutatedShape.VertexPositions[i] = shapeCenter + scale * (mutatedShape.VertexPositions[i] - shapeCenter);
}
}
Debug.Assert(mutatedShape != null);
return mutatedShape;
}
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));
}
}
}
}
