GreyMoments

Measure allowing to compute the zeroth to the third moment ponderated by the gray level of each pixel for shape. More...

Classes
class	ipsdk::imaproc::shape::analysis::GreyMomentsMsr
	Measurement object for measure GreyMoments. More...
class	ipsdk::imaproc::shape::analysis::GreyMomentsMsrInfo
	Information object for measure GreyMoments. More...
class	ipsdk::imaproc::shape::analysis::GreyMomentsMsrResults
	Measurement results object for measure GreyMoments. More...

Detailed Description

Measure allowing to compute the zeroth to the third moment ponderated by the gray level of each pixel for shape.

The GreyMoments measurement computes the , , and order scale-invariant central moment for each shape, ponderated by the voxels intensities.

The central moment for a given 2d shape are computed by :

Where are the coordinates of the shape grey barycenter (see GreyBarycenter).

The corresponding scale-invariant central moment is calculated by normalizing as follows : The central moment for a given 2d shape are computed by :

See also

https://en.wikipedia.org/wiki/Image_moment

The central grey moments for a 3d shape are computed using the same formula, using the z-axis in addition to the x and y axises [1] :

Where the grey 3d shape barycenter has coordinates .

The scale-invariant 3d moments can be obtained with the following equation :

Here is an example of 2d grey moment measurement :

References

[1] "Moments and Moment Invariants in Pattern Recognition, Chap. 2 Moment Invariants to Translation, Rotation and Scaling",Flusser, J.; Suk, T. & Zitova, B., John Wiley & Sons, Ltd, 2009, 13-47

Author

R. Abbal

Date

2017/03/23

Copyright

2017 Reactiv'IP, all right reserved.

Measure allowing to compute the zeroth to the third moment ponderated by the gray level of each pixel for shape

Measure synthesis :

Measure Type	Measure Unit Type	Parameter Type	Result Type	Shape Requirements
Intensity	None	None	Custom	Row Intersections

See Shape measurement for additional information on these pictograms

Measure Type :

This is an intensity measure

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

This measure can be used in 2d and 3d case

Measure Unit Type:

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

Measure Parameter Type :

Measure GreyMoments has no parameters

Measure Result Type :

Measure GreyMoments is associated to GreyMomentsMsrResults results

Measure Shape Requirements :

Measure GreyMoments requires row intersections from shape data

Measure Dependencies :

Measure GreyMoments depends on following measures :

Measure Mode	Measure Name	Measure Type	Measure Parameters
eMVP_2d3d	GreyBarycenter	GreyBarycenter

Note

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

See Shape Analysis 3d for more information on general shape 3d 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, "GreyMomentsMsr")
    
    #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("GreyMomentsMsr")
    
    # retrieve measure values
    outMsrValues = outMsr.getMeasureResult().getColl(0)
    print("First label first grey moment measurement equal " + str(outMsrValues[1].getMoment(shapeanalysis.GreyMomentsData.eGreyMoment3Id.eGM3I_X0Y0Z0)))

Generic example in 3d case :

import PyIPSDK
import PyIPSDK.IPSDKIPLShapeAnalysis as shapeanalysis

    # Create the infoset
    inMeasureInfoSet3d = PyIPSDK.createMeasureInfoSet3d()
    PyIPSDK.createMeasureInfo(inMeasureInfoSet3d, "GreyMomentsMsr")
    
    #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("GreyMomentsMsr")
    
    # retrieve measure values
    outMsrValues = outMsr.getMeasureResult().getColl(0)
    print("First label (X0, Y0, Z0) moment measurement equal " + str(outMsrValues[1].getMoment(shapeanalysis.GreyMomentsData.eGreyMoment3Id.eGM3I_X0Y0Z0)))

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

    // retrieve associated results
    const MeasureConstPtr& pGreyMomentsOutMsr = pOutMeasureSet->getMeasure("GreyMomentsMsr");
    const GreyMomentsMsrResults& outResults = static_cast<const GreyMomentsMsrResults&>(pGreyMomentsOutMsr->getMeasureResult());