OpticalFlow Class Reference

This CameraSensor calculates the optical flow at few points of the image based on a box matching technique. More...

#include <opticalflow.h>

Inherits lpzrobots::CameraSensor.

Collaboration diagram for OpticalFlow:

[legend]

List of all members.

Classes
struct	Vec2i
Public Types
typedef std::list< std::pair < Vec2i, int > >	FlowDelList
Public Member Functions
	OpticalFlow (OpticalFlowConf conf=getDefaultConf())
virtual	~OpticalFlow ()
virtual void	intern_init ()
	overload this function to initialized you data structures.
virtual bool	sense (const GlobalData &globaldata)
	Performs the calculations.
virtual int	getSensorNumber () const
	overload this function and return the number of sensor values
virtual int	get (sensor *sensors, int length) const
	overload this function and return the sensor values
Static Public Member Functions
static std::list< Pos >	getDefaultPoints (int num)
	calculates default positions for optical flow detection.
static OpticalFlowConf	getDefaultConf ()
	the default config has 2 points in and calculates the flow in X and Y
Protected Member Functions
Vec2i	calcFieldTransRGB (const Vec2i &field, const osg::Image *current, const osg::Image *last, double &minerror) const
	calculates the optimal transformation for one field in RGB using all three color channels
Static Protected Member Functions
static double	compareSubImg (const unsigned char *const I1, const unsigned char *const I2, const Vec2i &field, int size, int width, int height, int bytesPerPixel, int d_x, int d_y)
	compares a small part of two given images and returns the average absolute difference.
Protected Attributes
OpticalFlowConf	conf
int	num
std::list< Vec2i >	fields
sensor *	data
osg::Image *	lasts [4]
std::vector< Vec2i >	oldFlows
int	maxShiftX
int	maxShiftY
int	width
int	height
int	cnt
double	avgerror

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Detailed Description

This CameraSensor calculates the optical flow at few points of the image based on a box matching technique.

This can be applied directly to the camera image.

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Member Typedef Documentation

typedef std::list< std::pair<Vec2i,int> > FlowDelList

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Constructor & Destructor Documentation

OpticalFlow

(

OpticalFlowConf

conf = getDefaultConf()

)

See also:

CameraSensor for further parameter explanation.

~OpticalFlow

(

)

[virtual]

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Member Function Documentation

OpticalFlow::Vec2i calcFieldTransRGB	(	const Vec2i &	field,
		const osg::Image *	current,
		const osg::Image *	last,
		double &	minerror
	)			const [protected]

calculates the optimal transformation for one field in RGB using all three color channels

Parameters:

minerror

(is to return the minimum error achieved during the matching)

double compareSubImg	(	const unsigned char *const	I1,
		const unsigned char *const	I2,
		const Vec2i &	field,
		int	size,
		int	width,
		int	height,
		int	bytesPerPixel,
		int	d_x,
		int	d_y
	)			[static, protected]

compares a small part of two given images and returns the average absolute difference.

Field center, size and shift have to be choosen, so that no clipping is required!

Parameters:

	field	specifies position(center) of subimage to use for comparison
	size	specifies the size of the field edged in pixels
	d_x	shift in x direction
	d_y	shift in y direction

int get	(	sensor *	sensors,
		int	length
	)			const [virtual]

overload this function and return the sensor values

Implements CameraSensor.

static OpticalFlowConf getDefaultConf

(

)

[inline, static]

the default config has 2 points in and calculates the flow in X and Y

list< Pos > getDefaultPoints

(

int

num

)

[static]

calculates default positions for optical flow detection.

The points are in aranged horizontally in a line at the vertical center. For num 2 the points are at the border, 3 points there is additioanlly one is the center and so on.

virtual int getSensorNumber

(

)

const [inline, virtual]

overload this function and return the number of sensor values

Implements CameraSensor.

void intern_init

(

)

[virtual]

overload this function to initialized you data structures.

Use camera->getImage() to get the image from the camera

Implements CameraSensor.

bool sense

(

const GlobalData &

globaldata

)

[virtual]

Performs the calculations.

Implements CameraSensor.

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Member Data Documentation

double avgerror [protected]

int cnt [protected]

OpticalFlowConf conf [protected]

sensor* data [protected]

std::list<Vec2i> fields [protected]

int height [protected]

osg::Image* lasts[4] [protected]

int maxShiftX [protected]

int maxShiftY [protected]

int num [protected]

std::vector<Vec2i> oldFlows [protected]

int width [protected]

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

• opticalflow.h
• opticalflow.cpp