private void BuildShapeFromLengthAngleRepresentationDfs(
Vector[] vertices,
int currentEdgeIndex,
int parentEdgeIndex,
Vector parentEdgePoint1,
Vector parentEdgePoint2,
Func <int, int, double, double> lengthCalculator,
Func <int, int, double, double> angleCalculator)
{
// Determine edge direction and length
Vector parentEdgeVec = parentEdgePoint2 - parentEdgePoint1;
double length = lengthCalculator(currentEdgeIndex, parentEdgeIndex, parentEdgeVec.Length);
double angle = angleCalculator(currentEdgeIndex, parentEdgeIndex, Vector.AngleBetween(new Vector(1, 0), parentEdgeVec));
Vector edgeVec = new Vector(Math.Cos(angle), Math.Sin(angle)) * length;
// Choose correct start/end points
ShapeEdge currentEdge = this.Structure.Edges[currentEdgeIndex];
ShapeEdge parentEdge = this.Structure.Edges[parentEdgeIndex];
Vector edgePoint1, edgePoint2;
if (currentEdge.Index1 == parentEdge.Index1)
{
edgePoint1 = parentEdgePoint1;
edgePoint2 = edgePoint1 + edgeVec;
}
else if (currentEdge.Index1 == parentEdge.Index2)
{
edgePoint1 = parentEdgePoint2;
edgePoint2 = edgePoint1 + edgeVec;
}
else if (currentEdge.Index2 == parentEdge.Index1)
{
edgePoint2 = parentEdgePoint1;
edgePoint1 = edgePoint2 - edgeVec;
}
else
{
Debug.Assert(currentEdge.Index2 == parentEdge.Index2);
edgePoint2 = parentEdgePoint2;
edgePoint1 = edgePoint2 - edgeVec;
}
// Setup vertices (some vertex already was placed, but who cares?)
vertices[this.Structure.Edges[currentEdgeIndex].Index1] = edgePoint1;
vertices[this.Structure.Edges[currentEdgeIndex].Index2] = edgePoint2;
foreach (int childEdgeIndex in this.IterateNeighboringEdgeIndices(currentEdgeIndex))
{
if (childEdgeIndex != parentEdgeIndex)
{
BuildShapeFromLengthAngleRepresentationDfs(vertices, childEdgeIndex, currentEdgeIndex, edgePoint1, edgePoint2, lengthCalculator, angleCalculator);
}
}
}
public override bool Equals(object obj)
{
if (obj == null || GetType() != obj.GetType())
{
return(false);
}
ShapeEdge objCasted = (ShapeEdge)obj;
return(this.Index1 == objCasted.Index1 && this.Index2 == objCasted.Index2);
}
public Shape FitMeanShape(int width, int height, Vector rootEdgeDirection)
{
rootEdgeDirection = rootEdgeDirection.GetNormalized();
// Build tree with a root edge scale
Vector[] vertices = new Vector[this.Structure.VertexCount];
vertices[this.Structure.Edges[this.rootEdgeIndex].Index1] = new Vector(0, 0);
vertices[this.Structure.Edges[this.rootEdgeIndex].Index2] = rootEdgeDirection * this.RootEdgeMeanLength;
foreach (int childEdgeIndex in this.IterateNeighboringEdgeIndices(this.rootEdgeIndex))
{
BuildShapeFromLengthAngleRepresentationDfs(
vertices,
childEdgeIndex,
this.rootEdgeIndex,
vertices[this.Structure.Edges[this.rootEdgeIndex].Index1],
vertices[this.Structure.Edges[this.rootEdgeIndex].Index2],
(currentEdge, parentEdge, parentLength) => parentLength / this.GetEdgePairParams(parentEdge, currentEdge).MeanLengthRatio,
(currentEdge, parentEdge, parentAngle) => parentAngle + this.GetEdgePairParams(parentEdge, currentEdge).MeanAngle);
}
// Determine axis-aligned bounding box for the generated shapes
Vector min = new Vector(Double.PositiveInfinity, Double.PositiveInfinity);
Vector max = new Vector(Double.NegativeInfinity, Double.NegativeInfinity);
for (int i = 0; i < this.Structure.VertexCount; ++i)
{
min.X = Math.Min(min.X, vertices[i].X);
min.Y = Math.Min(min.Y, vertices[i].Y);
max.X = Math.Max(max.X, vertices[i].X);
max.Y = Math.Max(max.Y, vertices[i].Y);
}
Vector center = 0.5 * (min + max);
// Shift vertices to the center of image
for (int i = 0; i < this.Structure.VertexCount; ++i)
{
Vector pos = vertices[i];
pos -= center;
pos += new Vector(width * 0.5, height * 0.5);
vertices[i] = pos;
}
// Generate best possible edge widths
List <double> edgeWidths = new List <double>();
for (int i = 0; i < this.edgeParams.Count; ++i)
{
ShapeEdge edge = this.Structure.Edges[i];
double length = (vertices[edge.Index1] - vertices[edge.Index2]).Length;
edgeWidths.Add(length * this.edgeParams[i].WidthToEdgeLengthRatio);
}
return(new Shape(this.Structure, vertices, edgeWidths));
}
private static List <ILengthAngleConstraints> CalculateLengthAngleConstraints(ShapeConstraints shapeConstraints)
{
List <ILengthAngleConstraints> result = new List <ILengthAngleConstraints>();
for (int i = 0; i < shapeConstraints.ShapeStructure.Edges.Count; ++i)
{
ShapeEdge edge = shapeConstraints.ShapeStructure.Edges[i];
VertexConstraints vertex1Constraints = shapeConstraints.VertexConstraints[edge.Index1];
VertexConstraints vertex2Constraints = shapeConstraints.VertexConstraints[edge.Index2];
result.Add(BoxSetLengthAngleConstraints.FromVertexConstraints(vertex1Constraints, vertex2Constraints, 1, 16));
}
return(result);
}
public double CalculateEnergy(Shape shape)
{
if (shape == null)
{
throw new ArgumentNullException("shape");
}
if (shape.Structure != this.Structure)
{
throw new ArgumentException("Shape and model have different structures.", "shape");
}
double totalEnergy = 0;
// Root edge term
ShapeEdge rootEdge = this.Structure.Edges[this.rootEdgeIndex];
totalEnergy += this.CalculateRootEdgeEnergyTerm(
shape.VertexPositions[rootEdge.Index1], shape.VertexPositions[rootEdge.Index2]);
// Unary energy terms)
for (int i = 0; i < this.Structure.Edges.Count; ++i)
{
ShapeEdge edge = this.Structure.Edges[i];
totalEnergy += this.CalculateEdgeWidthEnergyTerm(
i, shape.EdgeWidths[i], shape.VertexPositions[edge.Index1], shape.VertexPositions[edge.Index2]);
}
// Pairwise energy terms
foreach (Tuple <int, int> edgePair in this.ConstrainedEdgePairs)
{
totalEnergy += this.CalculateEdgePairLengthEnergyTerm(
edgePair.Item1,
edgePair.Item2,
shape.GetEdgeVector(edgePair.Item1),
shape.GetEdgeVector(edgePair.Item2));
totalEnergy += this.CalculateEdgePairAngleEnergyTerm(
edgePair.Item1,
edgePair.Item2,
shape.GetEdgeVector(edgePair.Item1),
shape.GetEdgeVector(edgePair.Item2));
}
return(totalEnergy);
}
public static ShapeModel Learn(IEnumerable <Shape> shapes)
{
if (shapes == null)
{
throw new ArgumentNullException("shapes");
}
Shape firstShape = shapes.FirstOrDefault();
Dictionary <int, List <int> > vertexToEdges = new Dictionary <int, List <int> >();
for (int i = 0; i < firstShape.Structure.Edges.Count; ++i)
{
ShapeEdge edge = firstShape.Structure.Edges[i];
if (!vertexToEdges.ContainsKey(edge.Index1))
{
vertexToEdges.Add(edge.Index1, new List <int>());
}
vertexToEdges[edge.Index1].Add(i);
if (!vertexToEdges.ContainsKey(edge.Index2))
{
vertexToEdges.Add(edge.Index2, new List <int>());
}
vertexToEdges[edge.Index2].Add(i);
}
HashSet <Tuple <int, int> > neighboringEdgePairs = new HashSet <Tuple <int, int> >();
foreach (KeyValuePair <int, List <int> > vertexEdgesPair in vertexToEdges)
{
int startEdge = vertexEdgesPair.Value[0];
for (int otherEdgeIndex = 1; otherEdgeIndex < vertexEdgesPair.Value.Count; ++otherEdgeIndex)
{
neighboringEdgePairs.Add(new Tuple <int, int>(startEdge, vertexEdgesPair.Value[otherEdgeIndex]));
}
}
return(Learn(shapes, neighboringEdgePairs));
}
public double CalculateBackgroundPenalty(Shape shape, Vector point)
{
if (shape == null)
{
throw new ArgumentNullException("shape");
}
if (shape.Structure != this.Structure)
{
throw new ArgumentException("Shape and model have different structures.", "shape");
}
double maxPenalty = Double.NegativeInfinity;
for (int i = 0; i < this.Structure.Edges.Count; ++i)
{
ShapeEdge edge = this.Structure.Edges[i];
double penalty = this.CalculateBackgroundPenaltyForEdge(
point, shape.EdgeWidths[i], shape.VertexPositions[edge.Index1], shape.VertexPositions[edge.Index2]);
maxPenalty = Math.Max(maxPenalty, penalty);
}
return(maxPenalty);
}
private ShapeModel(
ShapeStructure structure,
IList <ShapeEdgeParams> edgeParams,
IDictionary <Tuple <int, int>, ShapeEdgePairParams> edgePairParams,
int rootEdgeIndex,
double rootEdgeMeanLength,
double rootEdgeLengthDeviation)
{
if (structure == null)
{
throw new ArgumentNullException("structure");
}
if (edgeParams == null)
{
throw new ArgumentNullException("edgeParams");
}
if (edgePairParams == null)
{
throw new ArgumentNullException("edgePairParams");
}
if (rootEdgeMeanLength <= 0)
{
throw new ArgumentOutOfRangeException("rootEdgeMeanLength", "Parameter value should be positive.");
}
if (rootEdgeLengthDeviation <= 0)
{
throw new ArgumentOutOfRangeException("rootEdgeLengthDeviation", "Parameter value should be positive.");
}
if (edgeParams.Count != structure.Edges.Count)
{
throw new ArgumentException("Edge params count is not equal to edge count.");
}
if (rootEdgeIndex < 0 || rootEdgeIndex >= structure.Edges.Count)
{
throw new ArgumentOutOfRangeException("rootEdgeIndex", "Parameter value should be a valid edge index.");
}
// Check edge pair constraints
foreach (Tuple <int, int> edgePair in edgePairParams.Keys)
{
if (edgePair.Item1 < 0 || edgePair.Item1 >= structure.Edges.Count || edgePair.Item2 < 0 || edgePair.Item2 >= structure.Edges.Count)
{
throw new ArgumentOutOfRangeException("edgePairParams", "Invalid edge index given.");
}
if (edgePair.Item1 == edgePair.Item2)
{
throw new ArgumentException("Edge pair constraint can't be specified for the single edge.", "edgePairParams");
}
if (edgePairParams.ContainsKey(new Tuple <int, int>(edgePair.Item2, edgePair.Item1)))
{
throw new ArgumentException("Duplicate pairwise constraints specified for some pair of edges.", "edgePairParams");
}
ShapeEdge edge1 = structure.Edges[edgePair.Item1];
ShapeEdge edge2 = structure.Edges[edgePair.Item2];
if (edge1.Index1 != edge2.Index1 && edge1.Index2 != edge2.Index1 &&
edge1.Index1 != edge2.Index2 && edge1.Index2 != edge2.Index2)
{
throw new ArgumentException("Constrained edge pairs should be connected.", "edgePairParams");
}
}
// Set
this.Structure = structure;
this.edgeParams = new List <ShapeEdgeParams>(edgeParams);
this.edgePairParams = new Dictionary <Tuple <int, int>, ShapeEdgePairParams>(edgePairParams);
this.rootEdgeIndex = rootEdgeIndex;
this.rootEdgeMeanLength = rootEdgeMeanLength;
this.rootEdgeLengthDeviation = rootEdgeLengthDeviation;
this.PostInit();
}
public static ShapeModel Learn(IEnumerable <Shape> shapes, IEnumerable <Tuple <int, int> > constrainedEdgePairs)
{
if (shapes == null)
{
throw new ArgumentNullException("shapes");
}
if (constrainedEdgePairs == null)
{
throw new ArgumentNullException("constrainedEdgePairs");
}
int shapeCount = shapes.Count();
if (shapeCount <= 1)
{
throw new ArgumentException("Can't learn from less than two shapes.", "shapes");
}
ShapeStructure structure = shapes.First().Structure;
if (!shapes.All(s => s.Structure == structure))
{
throw new ArgumentException("All the shapes should have the same structure.", "shapes");
}
// Learn root edge
double rootEdgeLengthDeviation = Double.PositiveInfinity;
double rootEdgeMeanLength = 0;
int rootEdgeIndex = -1;
for (int i = 0; i < structure.Edges.Count; ++i)
{
double lengthSum = 0, lengthSumSqr = 0;
foreach (Shape shape in shapes)
{
double edgeLength = shape.GetEdgeVector(i).Length;
lengthSum += edgeLength;
lengthSumSqr += edgeLength * edgeLength;
}
double meanLength = lengthSumSqr / lengthSum;
double lengthRatioDiffSqrSum = 0;
foreach (Shape shape in shapes)
{
double edgeLength = shape.GetEdgeVector(i).Length;
double lengthRatioDiff = edgeLength / meanLength - 1;
lengthRatioDiffSqrSum += lengthRatioDiff * lengthRatioDiff;
}
double lengthDeviation = Math.Sqrt(lengthRatioDiffSqrSum / shapeCount);
if (rootEdgeIndex == -1 || lengthDeviation < rootEdgeLengthDeviation)
{
rootEdgeLengthDeviation = lengthDeviation;
rootEdgeMeanLength = meanLength;
rootEdgeIndex = i;
}
}
// Learn edge params
List <ShapeEdgeParams> shapeEdgeParams = new List <ShapeEdgeParams>();
for (int i = 0; i < structure.Edges.Count; ++i)
{
double sum = 0, sumSqr = 0;
foreach (Shape shape in shapes)
{
double edgeLength = shape.GetEdgeVector(i).Length;
double ratio = shape.EdgeWidths[i] / edgeLength;
sum += ratio;
sumSqr += ratio * ratio;
}
double meanWidthToLengthRatio = sum / shapeCount;
double widthToLengthRatioDeviation = Math.Sqrt(sumSqr / shapeCount - meanWidthToLengthRatio * meanWidthToLengthRatio);
shapeEdgeParams.Add(new ShapeEdgeParams(meanWidthToLengthRatio, widthToLengthRatioDeviation));
}
// Learn edge pair params
Dictionary <Tuple <int, int>, ShapeEdgePairParams> shapeEdgePairParams =
new Dictionary <Tuple <int, int>, ShapeEdgePairParams>();
foreach (Tuple <int, int> edgePair in constrainedEdgePairs)
{
if (edgePair.Item1 < 0 || edgePair.Item1 >= structure.Edges.Count || edgePair.Item2 < 0 || edgePair.Item2 >= structure.Edges.Count)
{
throw new ArgumentOutOfRangeException("constrainedEdgePairs", "Set of constrained edge pairs contains invalid edge index.");
}
ShapeEdge edge1 = structure.Edges[edgePair.Item1];
ShapeEdge edge2 = structure.Edges[edgePair.Item2];
if (edge1.Index1 != edge2.Index1 && edge1.Index2 != edge2.Index1 &&
edge1.Index1 != edge2.Index2 && edge1.Index2 != edge2.Index2)
{
throw new ArgumentException("Constrained edge pairs should be connected.", "constrainedEdgePairs");
}
// Learn means
double lengthProdSum = 0, lengthSqrSum = 0;
double meanAngle = 0;
int shapesConsidered = 0;
foreach (Shape shape in shapes)
{
++shapesConsidered;
Vector edge1Vec = shape.GetEdgeVector(edgePair.Item1);
Vector edge2Vec = shape.GetEdgeVector(edgePair.Item2);
double length1 = edge1Vec.Length;
double length2 = edge2Vec.Length;
lengthProdSum += length1 * length2;
lengthSqrSum += length2 * length2;
double angle = Vector.AngleBetween(edge1Vec, edge2Vec);
meanAngle = MathHelper.InterpolateAngle(meanAngle, angle, 1.0 / shapesConsidered);
}
double meanLengthRatio = lengthProdSum / lengthSqrSum;
// Learn deviations
double angleAbsDiffSqrSum = 0;
double lengthDiffSqrSum = 0;
foreach (Shape shape in shapes)
{
Vector edge1Vec = shape.GetEdgeVector(edgePair.Item1);
Vector edge2Vec = shape.GetEdgeVector(edgePair.Item2);
double length1 = edge1Vec.Length;
double length2 = edge2Vec.Length;
double lengthDiff = length1 - meanLengthRatio * length2;
lengthDiffSqrSum += lengthDiff * lengthDiff;
double angle = Vector.AngleBetween(edge1Vec, edge2Vec);
double angleDiff = MathHelper.AngleAbsDifference(meanAngle, angle);
angleAbsDiffSqrSum += angleDiff * angleDiff;
}
double lengthDiffDeviation = Math.Sqrt(lengthDiffSqrSum / shapeCount);
double angleDeviation = Math.Sqrt(angleAbsDiffSqrSum / shapeCount);
if (shapeEdgePairParams.ContainsKey(edgePair) || shapeEdgePairParams.ContainsKey(new Tuple <int, int>(edgePair.Item2, edgePair.Item1)))
{
throw new ArgumentException("Same pair of edges is constrained more than once.", "constrainedEdgePairs");
}
shapeEdgePairParams.Add(edgePair, new ShapeEdgePairParams(meanAngle, meanLengthRatio, angleDeviation, lengthDiffDeviation));
}
return(new ShapeModel(structure, shapeEdgeParams, shapeEdgePairParams, rootEdgeIndex, rootEdgeMeanLength, rootEdgeLengthDeviation));
}
public Vector GetEdgeVector(int edgeIndex)
{
ShapeEdge edge = this.Structure.Edges[edgeIndex];
return(this.VertexPositions[edge.Index2] - this.VertexPositions[edge.Index1]);
}
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));
}
}
}
}
