Sphericity3d

Compute the sphericity of a 3d shape. More...

Classes
class	ipsdk::imaproc::shape::analysis::Sphericity3dMsr
	Measurement object for measure Sphericity3d. More...
class	ipsdk::imaproc::shape::analysis::Sphericity3dMsrInfo
	Information object for measure Sphericity3d. More...

Typedefs
typedef HolesBasicPolicyMsrParams	ipsdk::imaproc::shape::analysis::Sphericity3dMsrParams
	parameter type associated to class

Detailed Description

Compute the sphericity of a 3d shape.

Defined by Wadell in 1935, the sphericity of a shape is the ratio of the surface area of a sphere with the same volume as the shape to the surface area of the shape:

Where is the shape area, calculated with Area3d, and is the shape volume, calculated with Volume3d.

Here is an example of sphericity measurement :

See also

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

Author

H. Delestre

Date

2016/03/25

Copyright

2016 Reactiv'IP, all right reserved.

Compute the sphericity of a 3d shape

Measure synthesis :

Measure Type	Measure Unit Type	Parameter Type	Result Type	Shape Requirements
Generic	None	Sphericity3dMsrParams	Value (ipsdk::ipReal64)	Both

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 Sphericity3d is not associated to any unit [ipsdk::shape::analysis::eMsrUnitFormat::eMUF_NoUnit]

Measure Parameter Type :

Measure Sphericity3d is associated to Sphericity3dMsrParams parameters

Measure Result Type :

Measure Sphericity3d is associated to ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64> results

Measure Shape Requirements :

Measure Sphericity3d requires row intersections and boundary approximation from shape data

Measure Dependencies :

Measure Sphericity3d depends on following measures :

Measure Mode	Measure Name	Measure Type	Measure Parameters
eMVP_3d	Area3d	Area3d	createHolesBasicPolicyMsrParams(_pMsrParams->getValue<Sphericity3dMsrParams::ProcessHoles>())
eMVP_3d	Volume3d	Volume3d	createHolesBasicPolicyMsrParams(_pMsrParams->getValue<Sphericity3dMsrParams::ProcessHoles>())

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, "Sphericity3dMsr")
    
    #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("Sphericity3dMsr")
    
    # 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

    // opening grey level input image
    ImagePtr pInGreyImg3d = loadTiffImageFile(inputGreyImgPath, eTiffDirectoryMode::eTDM_Volume);

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

    // define a measure info set
    MeasureInfoSetPtr pMeasureInfoSet = MeasureInfoSet::create3dInstance();
    createMeasureInfo(pMeasureInfoSet, "Sphericity3dMsr", createHolesBasicPolicyMsrParams(bProcessHoles));
    
    // compute measure on shape 3d collection
    MeasureSetPtr pOutMeasureSet = shapeAnalysis3d(pInGreyImg3d, pShape3dColl, pMeasureInfoSet);

    // retrieve associated results
    const MeasureConstPtr& pSphericity3dOutMsr = pOutMeasureSet->getMeasure("Sphericity3dMsr");
    const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64>& outResults = static_cast<const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64>&>(pSphericity3dOutMsr->getMeasureResult());