OpenCV  3.0.0-dev
Open Source Computer Vision
Classes | Static Public Member Functions | List of all members
cv::SimpleBlobDetector Class Reference

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

#include "features2d.hpp"

Inheritance diagram for cv::SimpleBlobDetector:
cv::Feature2D cv::Algorithm


struct  Params

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< _Tp > load (const String &filename, const String &objname=String())
 Loads algorithm from the file. More...
template<typename _Tp >
static Ptr< _Tp > loadFromString (const String &strModel, const String &objname=String())
 Loads algorithm from a String. More...
template<typename _Tp >
static Ptr< _Tp > read (const FileNode &fn)
 Reads algorithm from the file node. More...

Additional Inherited Members

- 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). More...
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). More...
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
 Return true if detector object is empty. More...
- Public Member Functions inherited from cv::Algorithm
 Algorithm ()
virtual ~Algorithm ()
virtual void clear ()
 Clears the algorithm state. More...
virtual String getDefaultName () const
virtual void read (const FileNode &fn)
 Reads algorithm parameters from a file storage. More...
virtual void save (const String &filename) const
virtual void write (FileStorage &fs) const
 Stores algorithm parameters in a file storage. More...

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

static Ptr<SimpleBlobDetector> cv::SimpleBlobDetector::create ( const SimpleBlobDetector::Params parameters = SimpleBlobDetector::Params())

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