Number of 2D Connected Components

Returns the number of connected components associated to each 2d shape. More...

Classes
class	ipsdk::imaproc::shape::analysis::NbConnectedComponents2dMsr
	Measurement object for measure NbConnectedComponents2d. More...
class	ipsdk::imaproc::shape::analysis::NbConnectedComponents2dMsrInfo
	Information object for measure NbConnectedComponents2d. More...

Detailed Description

Returns the number of connected components associated to each 2d shape.

Natively, IPSDK assigns a single connected component to each shape. However, the result of a machine learning segmentation or a manual labelization can yield to several connected components assigned to the same label value.

Natively, IPSDK assigns a single connected component to each shape / label value.

Here is an example of measurement :

Author

R. Abbal

Date

2021/12/03

Copyright

2021 Reactiv'IP, all right reserved.

Returns the number of connected components associated to each 2d shape

Measure synthesis :

Measure Type	Measure Unit Type	Parameter Type	Result Type	Shape Requirements
Geometry 2d	None	None	Value (ipsdk::ipUInt64)	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 NbConnectedComponents2d is not associated to any unit [ipsdk::shape::analysis::eMsrUnitFormat::eMUF_NoUnit]

Measure Parameter Type :

Measure NbConnectedComponents2d has no parameters

Measure Result Type :

Measure NbConnectedComponents2d is associated to ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipUInt64> results

Measure Shape Requirements :

Measure NbConnectedComponents2d requires boundary approximation from shape data

Measure Dependencies :

Measure NbConnectedComponents2d has no dependency

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, "NbConnectedComponents2dMsr")
    
    #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("NbConnectedComponents2dMsr")
    
    # 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 label input image
    ImagePtr pInLabelImg2d = loadTiffImageFile(inputLabelImgPath);

    // define a measure info set
    MeasureInfoSetPtr pMeasureInfoSet = MeasureInfoSet::create2dInstance();
    createMeasureInfo(pMeasureInfoSet, "NbConnectedComponents2dMsr");
    
    // compute measure on shape 2d collection
    MeasureSetPtr pOutMeasureSet = labelAnalysis2d(pInLabelImg2d, pInLabelImg2d, pMeasureInfoSet);

    // retrieve associated results
    const MeasureConstPtr& pNbConnectedComponents2dOutMsr = pOutMeasureSet->getMeasure("NbConnectedComponents2dMsr");
    const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipUInt64>& outResults = static_cast<const ipsdk::shape::analysis::ValueMeasureResult<ipsdk::ipUInt64>&>(pNbConnectedComponents2dOutMsr->getMeasureResult());