cv::MSER Class Reference

Maximally stable extremal region extractor. More...

#include <opencv2/features2d.hpp>

Inheritance diagram for cv::MSER:

Public Member Functions
virtual void	detectRegions (InputArray image, std::vector< std::vector< Point > > &msers, std::vector< Rect > &bboxes)=0
	Detect MSER regions.
virtual String	getDefaultName () const CV_OVERRIDE
virtual int	getDelta () const =0
virtual int	getMaxArea () const =0
virtual int	getMinArea () const =0
virtual bool	getPass2Only () const =0
virtual void	setDelta (int delta)=0
virtual void	setMaxArea (int maxArea)=0
virtual void	setMinArea (int minArea)=0
virtual void	setPass2Only (bool f)=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.
void	read (const String &fileName)
virtual void	read (const FileNode &) CV_OVERRIDE
	Reads algorithm parameters from a file storage.
void	write (const String &fileName) const
virtual void	write (FileStorage &) const CV_OVERRIDE
	Stores algorithm parameters in a file storage.
void	write (const Ptr< FileStorage > &fs, const String &name=String()) 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
	simplified API for language bindingsThis is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Static Public Member Functions
static Ptr< MSER >	create (int _delta=5, int _min_area=60, int _max_area=14400, double _max_variation=0.25, double _min_diversity=.2, int _max_evolution=200, double _area_threshold=1.01, double _min_margin=0.003, int _edge_blur_size=5)
	Full consturctor for MSER detector.

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

Detailed Description

Maximally stable extremal region extractor.

The class encapsulates all the parameters of the MSER extraction algorithm (see wiki article).

• there are two different implementation of MSER: one for grey image, one for color image

• the grey image algorithm is taken from:nister2008linear ; the paper claims to be faster than union-find method; it actually get 1.5~2m/s on my centrino L7200 1.2GHz laptop.

• the color image algorithm is taken from:forssen2007maximally ; it should be much slower than grey image method ( 3~4 times ); the chi_table.h file is taken directly from paper's source code which is distributed under GPL.

• (Python) A complete example showing the use of the MSER detector can be found at samples/python/mser.py

Member Function Documentation

static Ptr<MSER> cv::MSER::create ( int  _delta = 5, int  _min_area = 60, int  _max_area = 14400, double  _max_variation = 0.25, double  _min_diversity = .2, int  _max_evolution = 200, double  _area_threshold = 1.01, double  _min_margin = 0.003, int  _edge_blur_size = 5  )

static

Python:
	retval	=	cv.MSER_create(	[, _delta[, _min_area[, _max_area[, _max_variation[, _min_diversity[, _max_evolution[, _area_threshold[, _min_margin[, _edge_blur_size]]]]]]]]]	)

Full consturctor for MSER detector.

Parameters

_delta	it compares \((size_{i}-size_{i-delta})/size_{i-delta}\)
_min_area	prune the area which smaller than minArea
_max_area	prune the area which bigger than maxArea
_max_variation	prune the area have similar size to its children
_min_diversity	for color image, trace back to cut off mser with diversity less than min_diversity
_max_evolution	for color image, the evolution steps
_area_threshold	for color image, the area threshold to cause re-initialize
_min_margin	for color image, ignore too small margin
_edge_blur_size	for color image, the aperture size for edge blur

virtual void cv::MSER::detectRegions ( InputArray  image, std::vector< std::vector< Point > > &  msers, std::vector< Rect > &  bboxes  )

pure virtual

Python:
	msers, bboxes	=	cv.MSER.detectRegions(	image	)

Detect MSER regions.

Parameters

image	input image (8UC1, 8UC3 or 8UC4, must be greater or equal than 3x3)
msers	resulting list of point sets
bboxes	resulting bounding boxes

virtual String cv::MSER::getDefaultName ( ) const

virtual

Python:
	retval	=	cv.MSER.getDefaultName(		)

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.

virtual int cv::MSER::getDelta ( ) const

pure virtual

Python:
	retval	=	cv.MSER.getDelta(		)

virtual int cv::MSER::getMaxArea ( ) const

pure virtual

Python:
	retval	=	cv.MSER.getMaxArea(		)

virtual int cv::MSER::getMinArea ( ) const

pure virtual

Python:
	retval	=	cv.MSER.getMinArea(		)

virtual bool cv::MSER::getPass2Only ( ) const

pure virtual

Python:
	retval	=	cv.MSER.getPass2Only(		)

virtual void cv::MSER::setDelta ( int  delta )

pure virtual

Python:
	None	=	cv.MSER.setDelta(	delta	)

virtual void cv::MSER::setMaxArea ( int  maxArea )

pure virtual

Python:
	None	=	cv.MSER.setMaxArea(	maxArea	)

virtual void cv::MSER::setMinArea ( int  minArea )

pure virtual

Python:
	None	=	cv.MSER.setMinArea(	minArea	)

virtual void cv::MSER::setPass2Only ( bool  f )

pure virtual

Python:
	None	=	cv.MSER.setPass2Only(	f	)

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

• features2d.hpp