struct returned by cv::moments [詳解]

#include <types.hpp>

公開メンバ関数
	Moments ()
	the default constructor

	Moments (double m00, double m10, double m01, double m20, double m11, double m02, double m30, double m21, double m12, double m03)
	the full constructor

公開変数類
spatial moments
CV_PROP_RW double	m00

CV_PROP_RW double	m10

CV_PROP_RW double	m01

CV_PROP_RW double	m20

CV_PROP_RW double	m11

CV_PROP_RW double	m02

CV_PROP_RW double	m30

CV_PROP_RW double	m21

CV_PROP_RW double	m12

CV_PROP_RW double	m03

central moments
CV_PROP_RW double	mu20

CV_PROP_RW double	mu11

CV_PROP_RW double	mu02

CV_PROP_RW double	mu30

CV_PROP_RW double	mu21

CV_PROP_RW double	mu12

CV_PROP_RW double	mu03

central normalized moments
CV_PROP_RW double	nu20

CV_PROP_RW double	nu11

CV_PROP_RW double	nu02

CV_PROP_RW double	nu30

CV_PROP_RW double	nu21

CV_PROP_RW double	nu12

CV_PROP_RW double	nu03

詳解

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:

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

覚え書き: $\texttt{mu}_{00}=\texttt{m}_{00}$ , $\texttt{nu}_{00}=1$ $\texttt{nu}_{10}=\texttt{mu}_{10}=\texttt{mu}_{01}=\texttt{mu}_{10}=0$ , 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.

覚え書き: 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.

このクラス詳解は次のファイルから抽出されました:

core/types.hpp

公開メンバ関数

公開変数類

詳解