Roughness2d

measure the roughness More...

Classes
class	ipsdk::imaproc::shape::analysis::Roughness2dMsr
	Measurement object for measure Roughness2d. More...
class	ipsdk::imaproc::shape::analysis::Roughness2dMsrInfo
	Information object for measure Roughness2d. More...
class	ipsdk::imaproc::shape::analysis::Roughness2dMsrParams
	Parameter object for measure Roughness2d. More...

Detailed Description

measure the roughness

Roughness measure needs, among other input parameters, the maximum distance between 2 points for the polygon approximation. This allows to extract another polygon approximation from the shape and computes its perimeter . The roughness is simply the ratio between those perimeters:

Where is the perimeter of the input shape and is the perimeter of the second polygon approximation using the measure input parameter PolygApproxMaxDist.

We note that and increases when the difference between and increases.

The following figure illustrates a concave shape with two polygon approximations. The blue polygon has a maximum distance polygon approximation of 1.5 (its default value) and the green one has an approximation of 10:

Here is an example of roughness measurement, with "consider holes" parameter set to 'true'and the maximum distance polygon approximation set to 10:

Author

R. Abbal

Date

2017/08/02

Copyright

2017 Reactiv'IP, all right reserved.

measure the roughness

Measure synthesis :

Measure Type	Measure Unit Type	Parameter Type	Result Type	Shape Requirements
Geometry 2d	None	Roughness2dMsrParams	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 Roughness2d is not associated to any unit [ipsdk::shape::analysis::eMsrUnitFormat::eMUF_NoUnit]

Measure Parameter Type :

Measure Roughness2d is associated to Roughness2dMsrParams parameters

Measure Result Type :

Measure Roughness2d is associated to ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64> results

Measure Shape Requirements :

Measure Roughness2d requires boundary approximation from shape data

Measure Dependencies :

Measure Roughness2d depends on following measures :

Measure Mode	Measure Name	Measure Type	Measure Parameters
eMVP_2d	Perimeter2d	Perimeter2d	createHolesBasicPolicyMsrParams(_pMsrParams->getValue<Roughness2dMsrParams::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, "Roughness2dMsr")
    
    #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("Roughness2dMsr")
    
    # 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
    const ipBool bProcessHoles = true;
    const ipReal64 maxDist = 10.;
    MeasureInfoSetPtr pMeasureInfoSet = MeasureInfoSet::create2dInstance();
    createMeasureInfo(pMeasureInfoSet, "Roughness2dMsr", createRoughness2dMsrParams(bProcessHoles, maxDist));
    
    // compute measure on shape 2d collection
    MeasureSetPtr pOutMeasureSet = shapeAnalysis2d(pInGreyImg2d, pShape2dColl, pMeasureInfoSet);

    // retrieve associated results
    const MeasureConstPtr& pRoughness2dOutMsr = pOutMeasureSet->getMeasure("Roughness2dMsr");
    const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64>& outResults = static_cast<const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64>&>(pRoughness2dOutMsr->getMeasureResult());