Degree of angularity 2d

ratio of the bounding edge angles and the distance of the edges from the center of the particle which is defined by the largest inscribed circle to the radius of the maximum inscribed circle More...

Classes
class	ipsdk::imaproc::shape::analysis::DegreeOfAngularity2dMsr
	Measurement object for measure DegreeOfAngularity2d. More...
class	ipsdk::imaproc::shape::analysis::DegreeOfAngularity2dMsrInfo
	Information object for measure DegreeOfAngularity2d. More...

Typedefs
typedef HolesBasicPolicyMsrParams	ipsdk::imaproc::shape::analysis::DegreeOfAngularity2dMsrParams
	parameter type associated to class

Detailed Description

ratio of the bounding edge angles and the distance of the edges from the center of the particle which is defined by the largest inscribed circle to the radius of the maximum inscribed circle

This measure allows to quantified the angularity of a shape using its associated maximum inscribed circle (see MaxInscribedCircle2d).

For each tops of the polygonal approximation of shape, we compute an angularity value given by :

where :

• is the angle formed by polygonal approximation at considered top .
• is the distance between maximum inscribed circle center and current top .
• is the radius of maximum inscribed circle
  

Then the global shape angularity value is simply given by the mean of previous values over all tops of the polygonal approximation of shape :

Here is an example of degree of angularity 2d computation on few caracteristic shapes :

See also

Tafesse Solomon, Sun Wenjuan, Fernlund Joanne, and Linbing Wang, A new image analysis technique to quantify particle angularity, Engineering Geology and Geophysics Research Group Royal Institute of Technology (KTH)

Lees, G. (1964) A new method for determining the angularity of particles. Sedimentology, 3, pp. 2-21.

Author

E.Noirfalise

Date

2017/07/18

Copyright

2017 Reactiv'IP, all right reserved.

ratio of the bounding edge angles and the distance of the edges from the center of the particle which is defined by the largest inscribed circle to the radius of the maximum inscribed circle

Measure synthesis :

Measure Type	Measure Unit Type	Parameter Type	Result Type	Shape Requirements
Geometry 2d	Angle	DegreeOfAngularity2dMsrParams	Value (ipsdk::ipReal64)	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 DegreeOfAngularity2d is associated to an angular (radians) measurement unit [ipsdk::shape::analysis::eMsrUnitFormat::eMUF_RadianUnit]

Measure Parameter Type :

Measure DegreeOfAngularity2d is associated to DegreeOfAngularity2dMsrParams parameters

Measure Result Type :

Measure DegreeOfAngularity2d is associated to ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64> results

Measure Shape Requirements :

Measure DegreeOfAngularity2d requires boundary approximation from shape data

Measure Dependencies :

Measure DegreeOfAngularity2d depends on following measures :

Measure Mode	Measure Name	Measure Type	Measure Parameters
eMVP_2d	MaxInscribedCircle2d	MaxInscribedCircle2d	createHolesBasicPolicyMsrParams(_pMsrParams->getValue<HolesBasicPolicyMsrParams::ProcessHoles>())

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, "DegreeOfAngularity2dMsr")
    
    #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("DegreeOfAngularity2dMsr")
    
    # 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 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, "DegreeOfAngularity2dMsr");
    
    // compute measure on shape 2d collection
    MeasureSetPtr pOutMeasureSet = shapeAnalysis2d(pInGreyImg2d, pShape2dColl, pMeasureInfoSet);

    // retrieve associated results
    const MeasureConstPtr& pDegreeOfAngularity2dOutMsr = pOutMeasureSet->getMeasure("DegreeOfAngularity2dMsr");
    const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64>& outResults = static_cast<const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64>&>(pDegreeOfAngularity2dOutMsr->getMeasureResult());