ConvexHullPerimeter2d

Measure allowing to compute the perimeter of the 2d convex hull for shape. More...

Classes
class	ipsdk::imaproc::shape::analysis::ConvexHullPerimeter2dMsr
	Measurement object for measure ConvexHullPerimeter2d. More...
class	ipsdk::imaproc::shape::analysis::ConvexHullPerimeter2dMsrInfo
	Information object for measure ConvexHullPerimeter2d. More...

Detailed Description

Measure allowing to compute the perimeter of the 2d convex hull for shape.

The ConvexHullPerimeter2d measure computes the perimeter of the convex hull calculated for each shape.

Here is an example of perimeter 2d measurement :

See [Concept] Convex Hull 2d for more details about the convex hull calculation and Perimeter2d for more details about the perimeter computation.

Author

R. Abbal

Date

2015/07/07

Copyright

2015 Reactiv'IP, all right reserved.

Measure allowing to compute the perimeter of the 2d convex hull for shape

Measure synthesis :

Measure Type	Measure Unit Type	Parameter Type	Result Type	Shape Requirements
Generic	Length	None	Value (ipsdk::ipReal64)	Boundary Approximation

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 2d case

Measure Unit Type:

Measure ConvexHullPerimeter2d is associated to a length measurement unit [ipsdk::shape::analysis::eMsrUnitFormat::eMUF_LengthUnit]

Measure Parameter Type :

Measure ConvexHullPerimeter2d has no parameters

Measure Result Type :

Measure ConvexHullPerimeter2d is associated to ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64> results

Measure Shape Requirements :

Measure ConvexHullPerimeter2d requires boundary approximation from shape data

Measure Dependencies :

Measure ConvexHullPerimeter2d depends on following measures :

Measure Mode	Measure Name	Measure Type	Measure Parameters
eMVP_2d	ConvexHull	ConvexHull2d

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, "ConvexHullPerimeter2dMsr")
    
    #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("ConvexHullPerimeter2dMsr")
    
    # 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>();
    readFromXmlFile(inputShape2dCollPath, *pShape2dColl);

    // define a measure info set
    MeasureInfoSetPtr pMeasureInfoSet = MeasureInfoSet::create2dInstance();
    createMeasureInfo(pMeasureInfoSet, "ConvexHullPerimeter2dMsr");

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

    // retrieve associated results
    const MeasureConstPtr& pConvexHullPerimeter2dOutMsr = pOutMeasureSet->getMeasure("ConvexHullPerimeter2dMsr");
    const ValueMeasureResult<ipReal64>& outResults = static_cast<const ValueMeasureResult<ipReal64>&>(pConvexHullPerimeter2dOutMsr->getMeasureResult());