HuMoments2d

Hu Moments of order up to 3 measurement of a shape This measure computes the Hu moment invariants for each shape. The moments are calculated according to https://en.wikipedia.org/wiki/Image_moment#Moment_invariants. More...

Classes
class	ipsdk::imaproc::shape::analysis::HuMoments2dMsr
	Measurement object for measure HuMoments2d. More...
class	ipsdk::imaproc::shape::analysis::HuMoments2dMsrInfo
	Information object for measure HuMoments2d. More...
class	ipsdk::imaproc::shape::analysis::HuMoments2dMsrResults
	Measurement results object for measure HuMoments2d. More...

Typedefs
typedef HolesBasicPolicyMsrParams	ipsdk::imaproc::shape::analysis::HuMoments2dMsrParams
	parameter type associated to class

Detailed Description

Hu Moments of order up to 3 measurement of a shape This measure computes the Hu moment invariants for each shape. The moments are calculated according to https://en.wikipedia.org/wiki/Image_moment#Moment_invariants.

Here is an example of Hu moment measurement in 2d case :

Author

R. Abbal

Date

2017/05/31

Copyright

2017 Reactiv'IP, all right reserved.

Hu Moments of order up to 3 measurement of a shape

Measure synthesis :

Measure Type	Measure Unit Type	Parameter Type	Result Type	Shape Requirements
Geometry 2d	None	HuMoments2dMsrParams	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 HuMoments2d is not associated to any unit [ipsdk::shape::analysis::eMsrUnitFormat::eMUF_NoUnit]

Measure Parameter Type :

Measure HuMoments2d is associated to HuMoments2dMsrParams parameters

Measure Result Type :

Measure HuMoments2d is associated to HuMoments2dMsrResults results

Measure Shape Requirements :

Measure HuMoments2d requires boundary approximation from shape data

Measure Dependencies :

Measure HuMoments2d 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, "HuMoments2dMsr")
    
    #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("HuMoments2dMsr")
    
    # retrieve measure values
    outMsrValues = outMsr.getMeasureResult().getColl(0)
    print("First label i1 Hu moment measurement equal " + str(outMsrValues[1].i1()))

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, "HuMoments2dMsr", createHolesBasicPolicyMsrParams(bProcessHoles));
    
    // compute measure on shape 2d collection
    MeasureSetPtr pOutMeasureSet = shapeAnalysis2d(pInGreyImg2d, pShape2dColl, pMeasureInfoSet);

    // retrieve associated results
    const MeasureConstPtr& pHuMoments2dOutMsr = pOutMeasureSet->getMeasure("HuMoments2dMsr");
    const HuMoments2dMsrResults& outResults = static_cast<const HuMoments2dMsrResults&>(pHuMoments2dOutMsr->getMeasureResult());