Nearest neighbors 2dSee full documentation

measure allowing to retrieve shapes at a given distance of measured shape

This measure allows to collect index and distance of neighbors of a shape given a user parameter distance threshold MaxDist (we collect shape indexes for which distance is lower or equal to this value). It is based on a geometric analysis of shape neighborhood.

Polygon approximation of shapes are used to compute inter-shape distances.

Parameter flag ProcessHoles allows to specify whether shape holes should be taken into account during computation. Please see Distance to nearest neighbor 2d for an explanation of effects of this flag.

The following figure illustrate evolution of number of neighbors for several shapes with respect to MaxDist parameter value (please take care of scale bar values) :

In previous figure, shapes (ie. the polygonal approximation of their boundary), are colored with respect to the number of associated neighbors.

measure allowing to retrieve shapes at a given distance of measured shape

Measure synthesis :

Measure Type	Measure Unit Type	Parameter Type	Result Type	Shape Requirements
Geometry 2d	None	NearestNeighbors2dMsrParams	Custom	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.createMeasureInfo(inMeasureInfoSet2d, "NearestNeighbors2dMsr")
    
    #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("NearestNeighbors2dMsr")
    
    # 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, "NearestNeighbors2dMsr", createNeighborsDistanceMsrParams(maxDist, bProcessHoles));
    
    // compute measure on shape 2d collection
    MeasureSetPtr pOutMeasureSet = shapeAnalysis2d(pInGreyImg2d, pShape2dColl, pMeasureInfoSet);

    // retrieve associated results
    const MeasureConstPtr& pNearestNeighbors2dOutMsr = pOutMeasureSet->getMeasure("NearestNeighbors2dMsr");
    const NearestNeighborsMsrResults& outResults = static_cast<const NearestNeighborsMsrResults&>(pNearestNeighbors2dOutMsr->getMeasureResult());