# Class TrifocalLinearPoint7

java.lang.Object
boofcv.alg.geo.trifocal.TrifocalLinearPoint7
Direct Known Subclasses:
`TrifocalAlgebraicPoint7`

```public class TrifocalLinearPoint7
extends Object```

Estimates the `TrifocalTensor` using a linear algorithm from 7 or more image points correspondences from three views, see page 394 of [1] for details. After an initial linear solution has been computed it is improved upon by applying geometric constraints. Note that the solution will not be optimal in a geometric or algebraic sense, but can be used as an initial estimate for refinement algorithms.

References:

• R. Hartley, and A. Zisserman, "Multiple View Geometry in Computer Vision", 2nd Ed, Cambridge 2003

`EnforceTrifocalGeometry`
• ## Field Summary

Fields
Modifier and Type Field Description
`protected DMatrixRMaj` `A`
`protected Point3D_F64` `e2`
`protected Point3D_F64` `e3`
`protected EnforceTrifocalGeometry` `enforce`
`protected TrifocalExtractGeometries` `extractEpipoles`
`protected NormalizationPoint2D` `N1`
`protected NormalizationPoint2D` `N2`
`protected NormalizationPoint2D` `N3`
`protected Point2D_F64` `p1_norm`
`protected Point2D_F64` `p2_norm`
`protected Point2D_F64` `p3_norm`
`protected TrifocalTensor` `solutionN`
`protected SingularValueDecomposition_F64<DMatrixRMaj>` `svdNull`
`protected DMatrixRMaj` `vectorizedSolution`
• ## Constructor Summary

Constructors
Constructor Description
`TrifocalLinearPoint7()`
• ## Method Summary

Modifier and Type Method Description
`protected void` `createLinearSystem​(List<AssociatedTriple> observations)`
Constructs the linear matrix that describes from the 3-point constraint with linear dependent rows removed
`boolean` ```process​(List<AssociatedTriple> observations, TrifocalTensor solution)```
Estimates the trifocal tensor given the set of observations
`protected void` `removeNormalization​(TrifocalTensor solution)`
Translates the trifocal tensor back into regular coordinate system
`protected boolean` `solveLinearSystem()`
Computes the null space of the linear system to find the trifocal tensor

### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

• ## Constructor Details

• ### TrifocalLinearPoint7

public TrifocalLinearPoint7()
• ## Method Details

• ### process

public boolean process​(List<AssociatedTriple> observations, TrifocalTensor solution)
Estimates the trifocal tensor given the set of observations
Parameters:
`observations` - Set of observations
`solution` - Output: Where the solution is written to
Returns:
true if successful and false if it fails
• ### createLinearSystem

protected void createLinearSystem​(List<AssociatedTriple> observations)
Constructs the linear matrix that describes from the 3-point constraint with linear dependent rows removed
• ### solveLinearSystem

protected boolean solveLinearSystem()
Computes the null space of the linear system to find the trifocal tensor
• ### removeNormalization

protected void removeNormalization​(TrifocalTensor solution)
Translates the trifocal tensor back into regular coordinate system