icl::cv::RDPApproximation Class Reference

Ramer-Douglas-Peucker algorithm. More...

#include <RDPApproximation.h>

List of all members.

Classes
struct	ChainPoint
Public Member Functions
	RDPApproximation (float epsilon=0.1f, int max_corners=0, int search_iters=3)
	default constructor with given arguments
const std::vector < utils::Point32f > &	approximate (const std::vector< utils::Point > &poly, bool polygon=true)
	approximates a polygon
const std::vector < utils::Point32f > &	approximate (const std::vector< utils::Point32f > &poly, bool polygon=true)
const std::vector < utils::Point32f > &	approximate (const utils::Point *begin, const utils::Point *end, const int size, bool polygon=true)
void	drawAllPoints (core::ImgBase *img, const icl64f &value)
	draws all points to the first channel of the given image with the given value
const std::vector < utils::Point32f > &	getLastApproximation () const
	returns the last approximation result
void	setEpsilon (float value)
void	setMaxCorners (float value)
void	setSearchIterations (float value)
float	getEpsilon () const
float	getMaxCorners () const
float	getSearchIterations () const
Private Member Functions
void	approximateCurve (const ChainPoint *first, const ChainPoint *last)
	approximates a curve
int	approximateCurveWithCap (const ChainPoint *first, const ChainPoint *last, int cap)
	tries to approximates a curve with a maximum number of points
void	approximatePolygon (const ChainPoint *cps, const int size, bool polygon)
	approximates a polygon
void	approximateWithCap (const ChainPoint *cps, const int size, bool polygon)
	approximates a rectangle if possible
Private Attributes
float	epsilon
	parameters
int	max_corners
int	search_iters
std::vector< utils::Point32f >	approximation
	result list

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Detailed Description

Ramer-Douglas-Peucker algorithm.

The algorithm takes an array of contour points as input. If a polygon should be approximated, then the two farthest points are found approximately. This points divide the polygon in two curves. For all curves the following is done recursively: First the perpendicular distance is calculated between each point and the line, which contains the first and last point of the curve. Afterwards the maximum distance is compared with an epsilon. The algorithm divides the curve further if the value is higher than the epsilon. Otherwise the begin and end point are taken for the result approximation. (see http://en.wikipedia.org/wiki/Ramer-Douglas-Peucker_algorithm for more information)

Parameters for the algorithm are:

• epsilon denotes the maximum ratio between the perpendicular and the line distance, that is used to filter points
• max_corners denotes the maximum number of corners; if the number of corners is higher, the algorithm return an empty list
• search_iters denotes the number of steps to find the two farthest points of a polygon

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Constructor & Destructor Documentation

icl::cv::RDPApproximation::RDPApproximation	(	float	epsilon = 0.1f,
		int	max_corners = 0,
		int	search_iters = 3
	)		[inline]

default constructor with given arguments

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Member Function Documentation

const std::vector<utils::Point32f>& icl::cv::RDPApproximation::approximate	(	const std::vector< utils::Point > &	poly,
		bool	polygon = true
	)

approximates a polygon

the param polygon shows, if the list is a polygon or a curve

const std::vector<utils::Point32f>& icl::cv::RDPApproximation::approximate	(	const std::vector< utils::Point32f > &	poly,
		bool	polygon = true
	)

const std::vector<utils::Point32f>& icl::cv::RDPApproximation::approximate	(	const utils::Point *	begin,
		const utils::Point *	end,
		const int	size,
		bool	polygon = true
	)

void icl::cv::RDPApproximation::approximateCurve	(	const ChainPoint *	first,
		const ChainPoint *	last
	)		[private]

approximates a curve

int icl::cv::RDPApproximation::approximateCurveWithCap	(	const ChainPoint *	first,
		const ChainPoint *	last,
		int	cap
	)		[private]

tries to approximates a curve with a maximum number of points

the param cap shows how much points can be in between of the first and the last point

void icl::cv::RDPApproximation::approximatePolygon	(	const ChainPoint *	cps,
		const int	size,
		bool	polygon
	)		[private]

approximates a polygon

void icl::cv::RDPApproximation::approximateWithCap	(	const ChainPoint *	cps,
		const int	size,
		bool	polygon
	)		[private]

approximates a rectangle if possible

void icl::cv::RDPApproximation::drawAllPoints	(	core::ImgBase *	img,
		const icl64f &	value
	)

draws all points to the first channel of the given image with the given value

float icl::cv::RDPApproximation::getEpsilon

(

)

const [inline]

const std::vector<utils::Point32f>& icl::cv::RDPApproximation::getLastApproximation

(

)

const [inline]

returns the last approximation result

float icl::cv::RDPApproximation::getMaxCorners

(

)

const [inline]

float icl::cv::RDPApproximation::getSearchIterations

(

)

const [inline]

void icl::cv::RDPApproximation::setEpsilon

(

float

value

)

[inline]

void icl::cv::RDPApproximation::setMaxCorners

(

float

value

)

[inline]

void icl::cv::RDPApproximation::setSearchIterations

(

float

value

)

[inline]

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Member Data Documentation

std::vector<utils::Point32f> icl::cv::RDPApproximation::approximation [private]

result list

float icl::cv::RDPApproximation::epsilon [private]

parameters

int icl::cv::RDPApproximation::max_corners [private]

int icl::cv::RDPApproximation::search_iters [private]

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

• /home/jenkins/workspace/icl-manual-trunk/icl-manual/ICLCV/src/ICLCV/RDPApproximation.h