cv::Moments Class Reference

struct returned by cv::moments More...

#include "types.hpp"

Public Member Functions
	Moments ()
	the default constructor More...
	Moments (double m00, double m10, double m01, double m20, double m11, double m02, double m30, double m21, double m12, double m03)
	the full constructor More...

Public Attributes
spatial moments
double	m00
double	m10
double	m01
double	m20
double	m11
double	m02
double	m30
double	m21
double	m12
double	m03
central moments
double	mu20
double	mu11
double	mu02
double	mu30
double	mu21
double	mu12
double	mu03
central normalized moments
double	nu20
double	nu11
double	nu02
double	nu30
double	nu21
double	nu12
double	nu03

Detailed Description

struct returned by cv::moments

The spatial moments \(\texttt{Moments::m}_{ji}\) are computed as:

\[\texttt{m} _{ji}= \sum _{x,y} \left ( \texttt{array} (x,y) \cdot x^j \cdot y^i \right )\]

The central moments \(\texttt{Moments::mu}_{ji}\) are computed as:

\[\texttt{mu} _{ji}= \sum _{x,y} \left ( \texttt{array} (x,y) \cdot (x - \bar{x} )^j \cdot (y - \bar{y} )^i \right )\]

where \((\bar{x}, \bar{y})\) is the mass center:

\[\bar{x} = \frac{\texttt{m}_{10}}{\texttt{m}_{00}} , \; \bar{y} = \frac{\texttt{m}_{01}}{\texttt{m}_{00}}\]

The normalized central moments \(\texttt{Moments::nu}_{ij}\) are computed as:

\[\texttt{nu} _{ji}= \frac{\texttt{mu}_{ji}}{\texttt{m}_{00}^{(i+j)/2+1}} .\]

Note

\(\texttt{mu}_{00}=\texttt{m}_{00}\), \(\texttt{nu}_{00}=1\) \(\texttt{nu}_{10}=\texttt{mu}_{10}=\texttt{mu}_{01}=\texttt{mu}_{10}=0\) , hence the values are not stored.

The moments of a contour are defined in the same way but computed using the Green's formula (see http://en.wikipedia.org/wiki/Green_theorem). So, due to a limited raster resolution, the moments computed for a contour are slightly different from the moments computed for the same rasterized contour.

Note

Since the contour moments are computed using Green formula, you may get seemingly odd results for contours with self-intersections, e.g. a zero area (m00) for butterfly-shaped contours.

Constructor & Destructor Documentation

cv::Moments::Moments

(

)

the default constructor

cv::Moments::Moments	(	double	m00,
		double	m10,
		double	m01,
		double	m20,
		double	m11,
		double	m02,
		double	m30,
		double	m21,
		double	m12,
		double	m03
	)

the full constructor

Member Data Documentation

double cv::Moments::m00

double cv::Moments::m01

double cv::Moments::m02

double cv::Moments::m03

double cv::Moments::m10

double cv::Moments::m11

double cv::Moments::m12

double cv::Moments::m20

double cv::Moments::m21

double cv::Moments::m30

double cv::Moments::mu02

double cv::Moments::mu03

double cv::Moments::mu11

double cv::Moments::mu12

double cv::Moments::mu20

double cv::Moments::mu21

double cv::Moments::mu30

double cv::Moments::nu02

double cv::Moments::nu03

double cv::Moments::nu11

double cv::Moments::nu12

double cv::Moments::nu20

double cv::Moments::nu21

double cv::Moments::nu30

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

• core/include/opencv2/core/types.hpp