Distance to nearest neighbor 2d

computation of distance to nearest neighbor for each shape More...

Classes
class	ipsdk::imaproc::shape::analysis::DistanceToNearestNeighbor2dMsr
	Measurement object for measure DistanceToNearestNeighbor2d. More...
class	ipsdk::imaproc::shape::analysis::DistanceToNearestNeighbor2dMsrInfo
	Information object for measure DistanceToNearestNeighbor2d. More...

Typedefs
typedef ipsdk::imaproc::shape::analysis::HolesBasicPolicyMsrParams	ipsdk::imaproc::shape::analysis::DistanceToNearestNeighbor2dMsrParams
	parameters type associated to measure

Detailed Description

computation of distance to nearest neighbor for each shape

This measure allows to compute the distance to the nearest neighbor for each shape. It is based on a geometric analysis of the shape neighborhood.

A polygonal approximation of shapes is used to compute the distances between shapes.

The parameter flag ProcessHoles allows to specify whether shape holes should be taken into account during computation :

In the previous figure :

• stands for inter-shape distance computed while ignoring holes
• stands for inter-shape distance computed while taking care of holes

Here is an example of nearest neighbor computation for several shapes :

In the previous figure shapes (ie. the polygonal approximation of boundaries), are colored with respect to the computed distance to its nearest neighbor.

Author

E.Noirfalise

Date

2017/07/04

Copyright

2017 Reactiv'IP, all right reserved.

computation of distance to nearest neighbor for each shape

Measure synthesis :

Measure Type	Measure Unit Type	Parameter Type	Result Type	Shape Requirements
Geometry 2d	Length	DistanceToNearestNeighbor2dMsrParams	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 DistanceToNearestNeighbor2d is associated to a length measurement unit [ipsdk::shape::analysis::eMsrUnitFormat::eMUF_LengthUnit]

Measure Parameter Type :

Measure DistanceToNearestNeighbor2d is associated to DistanceToNearestNeighbor2dMsrParams parameters

Measure Result Type :

Measure DistanceToNearestNeighbor2d is associated to ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64> results

Measure Shape Requirements :

Measure DistanceToNearestNeighbor2d requires boundary approximation from shape data

Measure Dependencies :

Measure DistanceToNearestNeighbor2d depends on following measures :

Measure Mode	Measure Name	Measure Type	Measure Parameters
eMVP_2d	Shape2dRTree	Shape2dRTree	createHolesBasicPolicyMsrParams(_pMsrParams->getValue<HolesBasicPolicyMsrParams::ProcessHoles>())
eMVP_2d	NearestNeighbor2dCollector	NearestNeighbor2dCollector	createHolesBasicPolicyMsrParams(_pMsrParams->getValue<HolesBasicPolicyMsrParams::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, "DistanceToNearestNeighbor2dMsr")
    
    #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("DistanceToNearestNeighbor2dMsr")
    
    # 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, "DistanceToNearestNeighbor2dMsr", createHolesBasicPolicyMsrParams(bProcessHoles));
    
    // compute measure on shape 2d collection
    MeasureSetPtr pOutMeasureSet = shapeAnalysis2d(pInGreyImg2d, pShape2dColl, pMeasureInfoSet);

    // retrieve associated results
    const MeasureConstPtr& pDistanceToNearestNeighbor2dOutMsr = pOutMeasureSet->getMeasure("DistanceToNearestNeighbor2dMsr");
    const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64>& outResults = static_cast<const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipReal64>&>(pDistanceToNearestNeighbor2dOutMsr->getMeasureResult());