LeastSquareEllipsoid3dSee full documentation

least square ellipsoid associated to shape tops

This measure allows to compute least square ellipsoid associated to each shape.

Given a shape, algorithm will compute a least square ellipsoid approximation of shape tops.

Estimated ellipsoid can be computed using a simple parametric estimation of shape tops or can be computed using a robust estimation technic. This behavior is ruled by measure parameter, see ipsdk::imaproc::attr::RobustEstimationConfig.

For more information on parametric estimation process (including outlier management) please reports to Parametric estimation.

Please refers to LeastSquareEllipse2d for an example of least square approximation in the 2d case of ellipse.

least square ellipsoid associated to shape tops

Measure synthesis :

Measure Type	Measure Unit Type	Parameter Type	Result Type	Shape Requirements
Geometry 3d	None	LeastSquareEllipsoid3dMsrParams	Custom	Boundary Approximation

See Shape measurement for additional information on these pictograms

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, "LeastSquareEllipsoid3dMsr")
    
    #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("LeastSquareEllipsoid3dMsr")
    
    # retrieve measure values
    outMsrValues = outMsr.getMeasureResult().getColl(0)
    print("First label estimation center : " + str(outMsrValues[1].first.centerX()) + ", " + str(outMsrValues[1].first.centerY()) + ", " + str(outMsrValues[1].first.centerZ()))
    print("First label estimation major radius : " + str(outMsrValues[1].first.getMajorRadius()))
    print("First label estimation medium radius : " + str(outMsrValues[1].first.getMediumRadius()))
    print("First label estimation minor radius : " + str(outMsrValues[1].first.getMinorRadius()))
    print("First label estimation alpha : " + str(outMsrValues[1].first.getAlpha()))
    print("First label estimation beta : " + str(outMsrValues[1].first.getBeta()))
    print("First label estimation chi : " + str(outMsrValues[1].first.getChi()))

Example of C++ code :

Example informations

Associated library

IPSDKIPLShapeAnalysis

Code Example

    // opening grey level input image
    ImagePtr pInGreyImg3d = loadTiffImageFile(inputGreyImgPath);

    // read entity shape 3d collection used for processing
    Shape3dCollPtr pShape3dColl = boost::make_shared<Shape3dColl>();
    IPSDK_REQUIRE(readFromBinaryFile(inputShape3dCollPath, *pShape3dColl) == true);

    // define a measure info set
    MeasureInfoSetPtr pMeasureInfoSet = MeasureInfoSet::create3dInstance();
    createMeasureInfo(pMeasureInfoSet, "LeastSquareEllipsoid3dMsr");
    
    // compute measure on shape 3d collection
    MeasureSetPtr pOutMeasureSet = shapeAnalysis3d(pInGreyImg3d, pShape3dColl, pMeasureInfoSet);

    // retrieve associated results
    const MeasureConstPtr& pLeastSquareEllipsoid3dOutMsr = pOutMeasureSet->getMeasure("LeastSquareEllipsoid3dMsr");
    const LeastSquareEllipsoid3dMsrResults& outResults = static_cast<const LeastSquareEllipsoid3dMsrResults&>(pLeastSquareEllipsoid3dOutMsr->getMeasureResult());