Inertia3dNormalOrientationTheta

Measure allowing to compute the 3d shape normal orientation (theta component of the (phi, theta) representation) from the second order moment matrix computed from the Inertia3d measurement. More...

Classes
class	ipsdk::imaproc::shape::analysis::Inertia3dNormalOrientationThetaMsr
	Measurement object for measure Inertia3dNormalOrientationTheta. More...
class	ipsdk::imaproc::shape::analysis::Inertia3dNormalOrientationThetaMsrInfo
	Information object for measure Inertia3dNormalOrientationTheta. More...

Detailed Description

Measure allowing to compute the 3d shape normal orientation (theta component of the (phi, theta) representation) from the second order moment matrix computed from the Inertia3d measurement.

This measure computes the normal orientation value between the x-y plane and the z-axis of the inertia matrix calculated for each 3D shape, without taking the voxels intensities into account, and returns the phi component, expressed in radians.

This orientation is calculated from the eigen vector related to the minimum eignen value.

Typically, this measure is usefull to determinate the orientation of a flat disk, for which the orientation inside the disk plane is not relevant.

To avoid redundancies in the orienation representation, the measure ensure that for a couple of angles ( , ), . is hence adjusted by rotating to if the initial value of .

Here is an example of theta orientation measurement :

Author

R. Abbal

Date

2021/05/03

Copyright

2021 ReactivIP, all right reserved.

Measure allowing to compute the 3d shape normal orientation (theta component of the (phi, theta) representation) from the second order moment matrix computed from the Inertia3d measurement

Measure synthesis :

Measure Type	Measure Unit Type	Parameter Type	Result Type	Shape Requirements
Generic	Angle	None	Value (ipsdk::ipReal64)	Row Intersections

See Shape measurement for additional information on these pictograms

Measure Type :

This is a generic measure

• it does not directly use shape or image data
• it can use dependencies to other measures to compute a result (see Measure Dependencies section)

This measure can only be used in 3d case

Measure Unit Type:

Measure Inertia3dNormalOrientationTheta is associated to an angular (radians) measurement unit [ipsdk::shape::analysis::eMsrUnitFormat::eMUF_RadianUnit]

Measure Parameter Type :

Measure Inertia3dNormalOrientationTheta has no parameters

Measure Result Type :

Measure Inertia3dNormalOrientationTheta is associated to ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64> results

Measure Shape Requirements :

Measure Inertia3dNormalOrientationTheta requires row intersections from shape data

Measure Dependencies :

Measure Inertia3dNormalOrientationTheta depends on following measures :

Measure Mode	Measure Name	Measure Type	Measure Parameters
eMVP_3d	Orientation	InertiaNormalOrientation3d

Note

See Shape Analysis 3d for more information on general shape 3d analysis and measurement usage.

Example of Python code :

Generic example in 3d case :

import PyIPSDK
import PyIPSDK.IPSDKIPLShapeAnalysis as shapeanalysis

    # Create the infoset
    inMeasureInfoSet3d = PyIPSDK.createMeasureInfoSet3d()
    PyIPSDK.createMeasureInfo(inMeasureInfoSet3d, "Inertia3dNormalOrientationThetaMsr")
    
    #Perform the analysis
    outMeasureSet = shapeanalysis.labelAnalysis3d(inGreyImg, inLabelImg, inMeasureInfoSet3d)
    
    # save results to csv format
    PyIPSDK.saveCsvMeasureFile(os.path.join(tmpPath,  "shape_analysis_results.csv"), outMeasureSet)
    
    # retrieve measure results
    outMsr = outMeasureSet.getMeasure("Inertia3dNormalOrientationThetaMsr")
    
    # retrieve measure values
    outMsrValues = outMsr.getMeasureResult().getColl(0)
    print("First label measurement equal " + str(outMsrValues[1]))

Example of C++ code :

Example informations

Associated library

IPSDKIPLShapeAnalysis

Code Example

    // define a measure info set
    MeasureInfoSetPtr pMeasureInfoSet = MeasureInfoSet::create3dInstance();
    createMeasureInfo(pMeasureInfoSet, "Inertia3dNormalOrientationThetaMsr");

    // compute measure
    MeasureSetPtr pOutMeasureSet = labelAnalysis3d(pLabelImg, pLabelImg, pMeasureInfoSet);

    // retrieve associated results
    const MeasureConstPtr& pOutMsr = pOutMeasureSet->getMeasure("Inertia3dNormalOrientationThetaMsr");
    const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64>& outResults = static_cast<const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64>&>(pOutMsr->getMeasureResult());