LeastSquareEllipse2d

least square ellipse associated to shape tops More...

Classes
class	ipsdk::imaproc::shape::analysis::LeastSquareEllipse2dMsr
	Measurement object for measure LeastSquareEllipse2d. More...
class	ipsdk::imaproc::shape::analysis::LeastSquareEllipse2dMsrInfo
	Information object for measure LeastSquareEllipse2d. More...
class	ipsdk::imaproc::shape::analysis::LeastSquareEllipse2dMsrResults
	Measurement results object for measure LeastSquareEllipse2d. More...

Typedefs
typedef attr::RobustEstimationConfig	ipsdk::imaproc::shape::analysis::LeastSquareEllipse2dMsrParams
	parameters type associated to measure

Detailed Description

least square ellipse associated to shape tops

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

Given a shape, algorithm will compute a least square ellipse approximation of shape tops :

Estimated ellipse 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 outliers management) please reports to Parametric estimation.

Here is an example of the least square ellipse computation on a grey scale image:

Author

E.Noirfalise

Date

2017/06/09

Copyright

2017 Reactiv'IP, all right reserved.

least square ellipse associated to shape tops

Measure synthesis :

Measure Type	Measure Unit Type	Parameter Type	Result Type	Shape Requirements
Geometry 2d	None	LeastSquareEllipse2dMsrParams	Custom	Boundary Approximation

See Shape measurement for additional information on these pictograms

Measure Type :

This is a geometry 2d measure

• it use shape 2d data to compute a result
• it optionally can use dependencies to other measures to compute a result (see Measure Dependencies section)

This measure can only be used in 2d case

Measure Unit Type:

Measure LeastSquareEllipse2d is not associated to any unit [ipsdk::shape::analysis::eMsrUnitFormat::eMUF_NoUnit]

Measure Parameter Type :

Measure LeastSquareEllipse2d is associated to LeastSquareEllipse2dMsrParams parameters

Measure Result Type :

Measure LeastSquareEllipse2d is associated to LeastSquareEllipse2dMsrResults results

Measure Shape Requirements :

Measure LeastSquareEllipse2d requires boundary approximation from shape data

Measure Dependencies :

Measure LeastSquareEllipse2d has no dependency

Note

See Shape Analysis 2d for more information on general shape 2d analysis and measurement usage.

Example of Python code :

Generic example in 2d case :

import PyIPSDK
import PyIPSDK.IPSDKIPLShapeAnalysis as shapeanalysis

    # Create the infoset
    inMeasureInfoSet2d = PyIPSDK.createMeasureInfoSet2d()
    PyIPSDK.createMeasureInfo(inMeasureInfoSet2d, "LeastSquareEllipse2dMsr")
    
    #Perform the analysis
    outMeasureSet = shapeanalysis.labelAnalysis2d(inGreyImg, inLabelImg2d, inMeasureInfoSet2d)
    
    # save results to csv format
    PyIPSDK.saveCsvMeasureFile(os.path.join(tmpPath,  "shape_analysis_results.csv"), outMeasureSet)
    
    # retrieve measure results
    outMsr = outMeasureSet.getMeasure("LeastSquareEllipse2dMsr")
    
    # retrieve measure values
    outMsrValues = outMsr.getMeasureResult().getColl(0)
    print("First label estimation orientation : " + str(outMsrValues[1].first.getOrientation()))
    print("First label estimation center : " + str(outMsrValues[1].first.centerX()) + ", " + str(outMsrValues[1].first.centerY()))
    print("First label estimation major radius : " + str(outMsrValues[1].first.getMajorRadius()))
    print("First label estimation minor radius : " + str(outMsrValues[1].first.getMinorRadius()))

Example of C++ code :

Example informations

Associated library

IPSDKIPLShapeAnalysis

Code Example

    // opening grey level input image
    ImagePtr pInGreyImg2d = loadTiffImageFile(inputGreyImgPath);

    // read entity shape 2d collection used for processing
    Shape2dCollPtr pShape2dColl = boost::make_shared<Shape2dColl>();
    IPSDK_REQUIRE(readFromXmlFile(inputShape2dCollPath, *pShape2dColl) == true);

    // define a measure info set
    MeasureInfoSetPtr pMeasureInfoSet = MeasureInfoSet::create2dInstance();
    createMeasureInfo(pMeasureInfoSet, "LeastSquareEllipse2dMsr");
    
    // compute measure on shape 2d collection
    MeasureSetPtr pOutMeasureSet = shapeAnalysis2d(pInGreyImg2d, pShape2dColl, pMeasureInfoSet);

    // retrieve associated results
    const MeasureConstPtr& pLeastSquareEllipse2dOutMsr = pOutMeasureSet->getMeasure("LeastSquareEllipse2dMsr");
    const LeastSquareEllipse2dMsrResults& outResults = static_cast<const LeastSquareEllipse2dMsrResults&>(pLeastSquareEllipse2dOutMsr->getMeasureResult());