ExampleComputeTrifocalTensor - Revision history

Peter at 00:31, 18 January 2022

2022-01-18T00:31:58Z

← Older revision		Revision as of 00:31, 18 January 2022
Line 2:		Line 2:

	'''Example Code:'''		'''Example Code:'''
	* [https://github.com/lessthanoptimal/BoofCV/blob/v0.38/examples/src/main/java/boofcv/examples/sfm/ExampleComputeTrifocalTensor.java ExampleComputeTrifocalTensor.java]		* [https://github.com/lessthanoptimal/BoofCV/blob/v0.40/examples/src/main/java/boofcv/examples/sfm/ExampleComputeTrifocalTensor.java ExampleComputeTrifocalTensor.java]

	'''Concepts:'''		'''Concepts:'''
Line 94:		Line 94:
	var triplePanel = new AssociatedTriplePanel();		var triplePanel = new AssociatedTriplePanel();
	triplePanel.setImages(		triplePanel.setImages(
	UtilImageIO.~~loadImage~~(UtilIO.pathExample("triple/" + name + "01.jpg")),		UtilImageIO.loadImageNotNull(UtilIO.pathExample("triple/" + name + "01.jpg")),
	UtilImageIO.~~loadImage~~(UtilIO.pathExample("triple/" + name + "02.jpg")),		UtilImageIO.loadImageNotNull(UtilIO.pathExample("triple/" + name + "02.jpg")),
	UtilImageIO.~~loadImage~~(UtilIO.pathExample("triple/" + name + "03.jpg")));		UtilImageIO.loadImageNotNull(UtilIO.pathExample("triple/" + name + "03.jpg")));
	triplePanel.setAssociation(inliers);		triplePanel.setAssociation(inliers);
	ShowImages.showWindow(triplePanel, "Inliers", true);		ShowImages.showWindow(triplePanel, "Inliers", true);

Peter at 22:05, 12 July 2021

2021-07-12T22:05:30Z

← Older revision		Revision as of 22:05, 12 July 2021
Line 5:		Line 5:

	'''Concepts:'''		'''Concepts:'''
	* ~~Three view geometry~~		* 3D Point Cloud
	* Reconstruction

	'''Related Examples:'''		'''Related Examples:'''
	* [[~~ExampleTrifocalTensorUses~~\| ~~Trifocal Tensor Uses]]~~		* [[Example_View_Point_Cloud\| Viewing a Point Cloud]]
	* [[Example_Multiview_Uncalibrated_Reconstruction_Sparse\| Scene Reconstruction]]

	= Example Code =		= Example Code =

Peter at 20:03, 12 July 2021

2021-07-12T20:03:56Z

← Older revision		Revision as of 20:03, 12 July 2021
Line 9:		Line 9:

	'''Related Examples:'''		'''Related Examples:'''
			* [[ExampleTrifocalTensorUses\| Trifocal Tensor Uses]]
	* [[Example_Multiview_Uncalibrated_Reconstruction_Sparse\| Scene Reconstruction]]		* [[Example_Multiview_Uncalibrated_Reconstruction_Sparse\| Scene Reconstruction]]

Peter at 19:59, 12 July 2021

2021-07-12T19:59:46Z

← Older revision		Revision as of 19:59, 12 July 2021
Line 1:		Line 1:
	Shows how to compute a trifocal tensor robustly from a set of image features between three views.		Shows how to compute a trifocal tensor robustly from a set of image features between three views.

	Example Code:		'''Example Code:'''
	* [https://github.com/lessthanoptimal/BoofCV/blob/v0.38/examples/src/main/java/boofcv/examples/sfm/ExampleComputeTrifocalTensor.java ExampleComputeTrifocalTensor.java]		* [https://github.com/lessthanoptimal/BoofCV/blob/v0.38/examples/src/main/java/boofcv/examples/sfm/ExampleComputeTrifocalTensor.java ExampleComputeTrifocalTensor.java]

	Concepts:		'''Concepts:'''
	* Three view geometry		* Three view geometry
	* Reconstruction		* Reconstruction

	Related Examples:		'''Related Examples:'''
	* [[Example_Multiview_Uncalibrated_Reconstruction_Sparse\| Scene Reconstruction]]		* [[Example_Multiview_Uncalibrated_Reconstruction_Sparse\| Scene Reconstruction]]

Peter: Created page with "Shows how to compute a trifocal tensor robustly from a set of image features between three views. Example Code: * [https://github.com/lessthanoptimal/BoofCV/blob/v0.38/exampl..."

2021-07-12T19:59:16Z

Created page with "Shows how to compute a trifocal tensor robustly from a set of image features between three views. Example Code: * [https://github.com/lessthanoptimal/BoofCV/blob/v0.38/exampl..."

New page

Shows how to compute a trifocal tensor robustly from a set of image features between three views.

Example Code:
* [https://github.com/lessthanoptimal/BoofCV/blob/v0.38/examples/src/main/java/boofcv/examples/sfm/ExampleComputeTrifocalTensor.java ExampleComputeTrifocalTensor.java]

Concepts:
* Three view geometry
* Reconstruction

Related Examples:
* [[Example_Multiview_Uncalibrated_Reconstruction_Sparse| Scene Reconstruction]]

= Example Code =

<syntaxhighlight lang="java">
/**
* This example shows how to robustly compute a trifocal tensor to features across three views. The trifocal tensor
* is used extensively in reconstruction scenarios and is more robust than applying two-view tensors (e.g. Fundamental
* and Essential matrices) which have issues along the epipolar lines.
*/
public class ExampleComputeTrifocalTensor {
/**
* Computes the trifocal tensor given three images. Returns the set of inlier features found when computing
* the tensor
*/
public static List<AssociatedTriple> imagesToTrifocal(
GrayU8 gray01, GrayU8 gray02, GrayU8 gray03, TrifocalTensor model ) {
// Using SURF features. Robust and fairly fast to compute
var configDetector = new ConfigFastHessian();
configDetector.maxFeaturesAll = 2500; // limit the feature count
configDetector.extract.radius = 4;
DetectDescribePoint<GrayU8, TupleDesc_F64> detDesc = FactoryDetectDescribe.surfStable(configDetector, null, null, GrayU8.class);

// Associate features across all three views using previous example code
var associateThree = new ExampleAssociateThreeView();
associateThree.initialize(detDesc);
associateThree.detectFeatures(gray01, 0);
associateThree.detectFeatures(gray02, 1);
associateThree.detectFeatures(gray03, 2);
DogArray<AssociatedTripleIndex> associatedIdx = associateThree.threeViewPairwiseAssociate();

System.out.println("features01.size = " + associateThree.features01.size);
System.out.println("features02.size = " + associateThree.features02.size);
System.out.println("features03.size = " + associateThree.features03.size);

// Convert the matched indexes into AssociatedTriple which contain the actual pixel coordinates
var associated = new DogArray<>(AssociatedTriple::new);
associatedIdx.forEach(p -> associated.grow().setTo(
associateThree.locations01.get(p.a),
associateThree.locations02.get(p.b),
associateThree.locations03.get(p.c)));

System.out.println("Total Matched Triples = " + associated.size);

// Storage for the found model. In this example we don't actually use the tensor.
List<AssociatedTriple> inliers = computeTrifocal(associated, model);
System.out.println("Remaining after RANSAC " + inliers.size());

return inliers;
}

/**
* Computes the Trifocal Tensor using RANSAC given associated features across 3-views. The found tensor
* is copied into model and the inliers are returned.
*/
public static List<AssociatedTriple> computeTrifocal( DogArray<AssociatedTriple> associated, TrifocalTensor model ) {
var configRansac = new ConfigRansac();
configRansac.iterations = 500;
configRansac.inlierThreshold = 1;

var configTri = new ConfigTrifocal();
ConfigTrifocalError configError = new ConfigTrifocalError();
configError.model = ConfigTrifocalError.Model.REPROJECTION_REFINE;

Ransac<TrifocalTensor, AssociatedTriple> ransac =
FactoryMultiViewRobust.trifocalRansac(configTri, configError, configRansac);

ransac.process(associated.toList());
model.setTo(ransac.getModelParameters());

return ransac.getMatchSet();
}

public static void main( String[] args ) {
String name = "rock_leaves_";
GrayU8 gray01 = UtilImageIO.loadImage(UtilIO.pathExample("triple/" + name + "01.jpg"), GrayU8.class);
GrayU8 gray02 = UtilImageIO.loadImage(UtilIO.pathExample("triple/" + name + "02.jpg"), GrayU8.class);
GrayU8 gray03 = UtilImageIO.loadImage(UtilIO.pathExample("triple/" + name + "03.jpg"), GrayU8.class);

// Compute the trifocal tensor which matches features inside these images
var model = new TrifocalTensor();
List<AssociatedTriple> inliers = imagesToTrifocal(gray01, gray02, gray03, model);

// Show inlier associations from RANSAC
var triplePanel = new AssociatedTriplePanel();
triplePanel.setImages(
UtilImageIO.loadImage(UtilIO.pathExample("triple/" + name + "01.jpg")),
UtilImageIO.loadImage(UtilIO.pathExample("triple/" + name + "02.jpg")),
UtilImageIO.loadImage(UtilIO.pathExample("triple/" + name + "03.jpg")));
triplePanel.setAssociation(inliers);
ShowImages.showWindow(triplePanel, "Inliers", true);
}
}
</syntaxhighlight>