Length of graph associated to skeleton 2d.

Skeleton 2d length measure is based on skeleton 2d measure (see [Concept] Skeleton 2d). This measure allows to compute sum of length of edges composing a shape 2d skeleton.

Searched edge type can be customized (setting measure parameter ipsdk::geom::eSkeletonEdgeCategory) :

eSEC_All to process all edges
eSEC_Leaf to process only leaf edges which are edges connected to a polygon point (red edges for main skeleton and black edges for hole skeleton)
eSEC_Branch to process only branch edges which are edges not connected to polygon point (green edges for main skeleton and blue edges for hole skeleton)

Here is an example of measure results for different skeleton 2d holes processing policy and different searched edge types.

Length of graph associated to skeleton 2d

Measure synthesis :

Measure Type	Measure Unit Type	Parameter Type	Result Type	Shape Requirements
Generic	Length	Skeleton2dLengthMsrParams	Value (ipsdk::ipReal64)	Boundary Approximation

See Shape measurement for additional information on these pictograms

Example of Python code :

Generic example in 2d case :

import PyIPSDK

import PyIPSDK.IPSDKIPLShapeAnalysis as shapeanalysis

    # Create the infoset
    inMeasureInfoSet2d = PyIPSDK.createMeasureInfoSet2d(PyIPSDK.createGeometricCalibration2d(1,1,'px'))
    PyIPSDK.createMeasureInfo(inMeasureInfoSet2d, "Skeleton2dLengthMsr", shapeanalysis.createSkeleton2dLengthMsrParams(PyIPSDK.eSHP_Ignored, PyIPSDK.eSEC_Leaf))
    
    #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("Skeleton2dLengthMsr")
    
    # 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, "Skeleton2dLengthMsr", createSkeleton2dLengthMsrParams(skeleton2dHolesPolicy, skeletonEdgeCategory));
    
    // compute measure on shape 2d collection
    MeasureSetPtr pOutMeasureSet = shapeAnalysis2d(pInGreyImg2d, pShape2dColl, pMeasureInfoSet);
    // retrieve associated results
    const MeasureConstPtr& pSkeleton2dLengthOutMsr = pOutMeasureSet->getMeasure("Skeleton2dLengthMsr");
    const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64>& outResults = static_cast<const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64>&>(pSkeleton2dLengthOutMsr->getMeasureResult());