OpenCV  4.10.0-pre
Open Source Computer Vision
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Classes | Public Member Functions | Static Public Member Functions | List of all members
cv::SimpleBlobDetector Class Referenceabstract

Class for extracting blobs from an image. : More...

#include <opencv2/features2d.hpp>

Collaboration diagram for cv::SimpleBlobDetector:

Classes

struct  Params
 

Public Member Functions

virtual const std::vector< std::vector< cv::Point > > & getBlobContours () const
 
virtual String getDefaultName () const CV_OVERRIDE
 
virtual SimpleBlobDetector::Params getParams () const =0
 
virtual void setParams (const SimpleBlobDetector::Params &params)=0
 
- Public Member Functions inherited from cv::Feature2D
virtual ~Feature2D ()
 
virtual void compute (InputArray image, std::vector< KeyPoint > &keypoints, OutputArray descriptors)
 Computes the descriptors for a set of keypoints detected in an image (first variant) or image set (second variant).
 
virtual void compute (InputArrayOfArrays images, std::vector< std::vector< KeyPoint > > &keypoints, OutputArrayOfArrays descriptors)
 
virtual int defaultNorm () const
 
virtual int descriptorSize () const
 
virtual int descriptorType () const
 
virtual void detect (InputArray image, std::vector< KeyPoint > &keypoints, InputArray mask=noArray())
 Detects keypoints in an image (first variant) or image set (second variant).
 
virtual void detect (InputArrayOfArrays images, std::vector< std::vector< KeyPoint > > &keypoints, InputArrayOfArrays masks=noArray())
 
virtual void detectAndCompute (InputArray image, InputArray mask, std::vector< KeyPoint > &keypoints, OutputArray descriptors, bool useProvidedKeypoints=false)
 
virtual bool empty () const CV_OVERRIDE
 Return true if detector object is empty.
 
virtual void read (const FileNode &) CV_OVERRIDE
 Reads algorithm parameters from a file storage.
 
void read (const String &fileName)
 
void write (const Ptr< FileStorage > &fs, const String &name) const
 
void write (const String &fileName) const
 
virtual void write (FileStorage &) const CV_OVERRIDE
 Stores algorithm parameters in a file storage.
 
void write (FileStorage &fs, const String &name) const
 
- Public Member Functions inherited from cv::Algorithm
 Algorithm ()
 
virtual ~Algorithm ()
 
virtual void clear ()
 Clears the algorithm state.
 
virtual void save (const String &filename) const
 
void write (const Ptr< FileStorage > &fs, const String &name=String()) const
 
void write (FileStorage &fs, const String &name) const
 

Static Public Member Functions

static Ptr< SimpleBlobDetectorcreate (const SimpleBlobDetector::Params &parameters=SimpleBlobDetector::Params())
 
- Static Public Member Functions inherited from cv::Algorithm
template<typename _Tp >
static Ptr< _Tpload (const String &filename, const String &objname=String())
 Loads algorithm from the file.
 
template<typename _Tp >
static Ptr< _TploadFromString (const String &strModel, const String &objname=String())
 Loads algorithm from a String.
 
template<typename _Tp >
static Ptr< _Tpread (const FileNode &fn)
 Reads algorithm from the file node.
 

Additional Inherited Members

- Protected Member Functions inherited from cv::Algorithm
void writeFormat (FileStorage &fs) const
 

Detailed Description

Class for extracting blobs from an image. :

The class implements a simple algorithm for extracting blobs from an image:

  1. Convert the source image to binary images by applying thresholding with several thresholds from minThreshold (inclusive) to maxThreshold (exclusive) with distance thresholdStep between neighboring thresholds.
  2. Extract connected components from every binary image by findContours and calculate their centers.
  3. Group centers from several binary images by their coordinates. Close centers form one group that corresponds to one blob, which is controlled by the minDistBetweenBlobs parameter.
  4. From the groups, estimate final centers of blobs and their radiuses and return as locations and sizes of keypoints.

This class performs several filtrations of returned blobs. You should set filterBy* to true/false to turn on/off corresponding filtration. Available filtrations:

Default values of parameters are tuned to extract dark circular blobs.

Member Function Documentation

◆ create()

static Ptr< SimpleBlobDetector > cv::SimpleBlobDetector::create ( const SimpleBlobDetector::Params parameters = SimpleBlobDetector::Params())
static
Python:
cv.SimpleBlobDetector.create([, parameters]) -> retval
cv.SimpleBlobDetector_create([, parameters]) -> retval

◆ getBlobContours()

virtual const std::vector< std::vector< cv::Point > > & cv::SimpleBlobDetector::getBlobContours ( ) const
virtual
Python:
cv.SimpleBlobDetector.getBlobContours() -> retval

◆ getDefaultName()

virtual String cv::SimpleBlobDetector::getDefaultName ( ) const
virtual
Python:
cv.SimpleBlobDetector.getDefaultName() -> retval

Returns the algorithm string identifier. This string is used as top level xml/yml node tag when the object is saved to a file or string.

Reimplemented from cv::Feature2D.

◆ getParams()

virtual SimpleBlobDetector::Params cv::SimpleBlobDetector::getParams ( ) const
pure virtual
Python:
cv.SimpleBlobDetector.getParams() -> retval

◆ setParams()

virtual void cv::SimpleBlobDetector::setParams ( const SimpleBlobDetector::Params params)
pure virtual
Python:
cv.SimpleBlobDetector.setParams(params) -> None

The documentation for this class was generated from the following file: