Nearest neighbors 2d

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

Classes
class	ipsdk::imaproc::shape::analysis::NearestNeighbors2dMsr
	Measurement object for measure NearestNeighbors2d. More...
class	ipsdk::imaproc::shape::analysis::NearestNeighbors2dMsrInfo
	Information object for measure NearestNeighbors2d. More...

Typedefs
typedef ipsdk::imaproc::shape::analysis::NeighborsDistanceMsrParams	ipsdk::imaproc::shape::analysis::NearestNeighbors2dMsrParams
	parameters type associated to measure

Detailed Description

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.

Author

E.Noirfalise

Date

2017/07/27

Copyright

2017 Reactiv'IP, all right reserved.

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

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 NearestNeighbors2d is not associated to any unit [ipsdk::shape::analysis::eMsrUnitFormat::eMUF_NoUnit]

Measure Parameter Type :

Measure NearestNeighbors2d is associated to NearestNeighbors2dMsrParams parameters

Measure Result Type :

Measure NearestNeighbors2d is associated to NearestNeighborsMsrResults results

Measure Shape Requirements :

Measure NearestNeighbors2d requires boundary approximation from shape data

Measure Dependencies :

Measure NearestNeighbors2d depends on following measures :

Measure Mode	Measure Name	Measure Type	Measure Parameters
eMVP_2d	Shape2dRTree	Shape2dRTree	createHolesBasicPolicyMsrParams(_pMsrParams->getValue<NeighborsDistanceMsrParams::ProcessHoles>())
eMVP_2d	Neighbors2dDistanceCollector	Neighbors2dDistanceCollector	boost::make_shared<NeighborsDistanceMsrParams>(*_pMsrParams)

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, "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());