Class PPF3DDetector

Namespace

Emgu.CV.PpfMatch3d

Assembly

Emgu.CV.dll

Class, allowing the load and matching 3D models.

public class PPF3DDetector : UnmanagedObject, IDisposable

Inheritance

object

DisposableObject

UnmanagedObject

PPF3DDetector

Implements

IDisposable

Inherited Members

UnmanagedObject._ptr

UnmanagedObject.Ptr

DisposableObject.Dispose()

DisposableObject.ReleaseManagedResources()

object.GetType()

object.MemberwiseClone()

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Constructors

PPF3DDetector(double, double, double)

Create a new PPF3DDetector

public PPF3DDetector(double relativeSamplingStep = 0.05, double relativeDistanceStep = 0.05, double numAngles = 30)

Parameters

relativeSamplingStep double

Sampling distance relative to the object's diameter. Models are first sampled uniformly in order to improve efficiency. Decreasing this value leads to a denser model, and a more accurate pose estimation but the larger the model, the slower the training. Increasing the value leads to a less accurate pose computation but a smaller model and faster model generation and matching. Beware of the memory consumption when using small values.

relativeDistanceStep double

The discretization distance of the point pair distance relative to the model's diameter. This value has a direct impact on the hashtable. Using small values would lead to too fine discretization, and thus ambiguity in the bins of hashtable. Too large values would lead to no discrimination over the feature vectors and different point pair features would be assigned to the same bin. This argument defaults to the value of RelativeSamplingStep. For noisy scenes, the value can be increased to improve the robustness of the matching against noisy points.

numAngles double

Set the discretization of the point pair orientation as the number of subdivisions of the angle. This value is the equivalent of RelativeDistanceStep for the orientations. Increasing the value increases the precision of the matching but decreases the robustness against incorrect normal directions. Decreasing the value decreases the precision of the matching but increases the robustness against incorrect normal directions. For very noisy scenes where the normal directions can not be computed accurately, the value can be set to 25 or 20.

Methods

DisposeObject()

Release all the unmanaged memory associated with this 3d detector

protected override void DisposeObject()

Match(Mat, VectorOfPose3D, double, double)

Matches a trained model across a provided scene.

public void Match(Mat scene, VectorOfPose3D results, double relativeSceneSampleStep, double relativeSceneDistance)

Parameters

scene Mat

Scene Point cloud for the scene

results VectorOfPose3D

Results List of output poses

relativeSceneSampleStep double

The ratio of scene points to be used for the matching after sampling with relativeSceneDistance. For example, if this value is set to 1.0/5.0, every 5th point from the scene is used for pose estimation. This parameter allows an easy trade-off between speed and accuracy of the matching. Increasing the value leads to less points being used and in turn to a faster but less accurate pose computation. Decreasing the value has the inverse effect.

relativeSceneDistance double

Set the distance threshold relative to the diameter of the model. This parameter is equivalent to relativeSamplingStep in the training stage. This parameter acts like a prior sampling with the relativeSceneSampleStep parameter.

TrainModel(Mat)

Trains a new model.

public void TrainModel(Mat model)

Parameters

model Mat

Model The input point cloud with normals (Nx6)

Remarks

Uses the parameters set in the constructor to downsample and learn a new model. When the model is learn, the instance gets ready for calling "match".