IntegralGradient is used for calculating rectangular image gradients rapidly More...

#include <IntegralImage.h>

Public Member Functions
void	GetAveGradient (CvRect &rect, double dirx, double diry)
	Calculate the average gradient for the given rectangular area in the image.
void	GetGradient (CvRect &rect, double dirx, double diry, int *count=0)
	Calculate the gradient for the given rectangular area in the image.
	IntegralGradient ()
void	Update (IplImage *gray)
	Update intermediate images for calculating the gradients to the given image.
	~IntegralGradient ()
Protected Member Functions
void	CalculatePointNormals (IplImage *gray)
Protected Attributes
IntegralImage	integx
IntegralImage	integy
IplImage *	normalx
IplImage *	normaly

Detailed Description

IntegralGradient is used for calculating rectangular image gradients rapidly

We calculate IntegralImage:s based on point normals for 4-pixel intersections (see Donahue1992). Using the integral images it is possible to make fast gradient calculations to any image rectangle. This approach is useful when we need to calculate many gradient rectangles for the same image.

(See SampleIntegralImage.cpp)

Examples:: SampleIntegralImage.cpp.

Definition at line 136 of file IntegralImage.h.

Constructor & Destructor Documentation

alvar::IntegralGradient::IntegralGradient ( )

Definition at line 168 of file IntegralImage.cpp.

alvar::IntegralGradient::~IntegralGradient ( )

Definition at line 172 of file IntegralImage.cpp.

Member Function Documentation

void alvar::IntegralGradient::CalculatePointNormals ( IplImage * gray ) [protected]

Definition at line 128 of file IntegralImage.cpp.

void alvar::IntegralGradient::GetAveGradient	(	CvRect &	rect,
		double *	dirx,
		double *	diry
	)

Calculate the average gradient for the given rectangular area in the image.

Parameters:

dirx	Method fills in the x-component of the gradient here
diry	Method fills in the y-component of the gradient here

Examples:: SampleIntegralImage.cpp.

Definition at line 187 of file IntegralImage.cpp.

void alvar::IntegralGradient::GetGradient	(	CvRect &	rect,
		double *	dirx,
		double *	diry,
		int *	count = `0`
	)

Calculate the gradient for the given rectangular area in the image.

Parameters:

dirx	Method fills in the x-component of the gradient here
diry	Method fills in the y-component of the gradient here
count	If this parameter is not 0 it is filled with number of pixels in the rectangle.

Definition at line 181 of file IntegralImage.cpp.

void alvar::IntegralGradient::Update ( IplImage * gray )

Update intermediate images for calculating the gradients to the given image.

Parameters: