The class estimates the skew of a document page. The methodology is based on "Skew estimation of natural images based on a salient line detector", Hyung Il Koo and Nam Ik Cho More...

#include <SkewEstimation.h>

Inheritance diagram for rdf::BaseSkewEstimation:

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Collaboration diagram for rdf::BaseSkewEstimation:

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Public Types
enum	EdgeDirection { HORIZONTAL = 0, VERTICAL }

Public Member Functions
	BaseSkewEstimation (const cv::Mat &img=cv::Mat(), const cv::Mat &mask=cv::Mat())
	Initializes a new instance of the BaseSkewEstimation class. More...

void	setImages (const cv::Mat &img, const cv::Mat &mask=cv::Mat())
	Sets the images. More...

bool	compute ()
	Computes the skew angle based on "Skew Estimation of natural images based on a salient line detector", Hyung Il Koo and Nam Ik Choo. More...

double	getAngle ()
	Gets the skew angle. More...

QVector< QVector4D >	getSelectedLines () const

bool	isEmpty () const override
	Determines whether this instance is empty. More...

virtual QString	toString () const override
	Summarize the method as string. Not yet implemented. More...

void	setFixedThr (bool f)

QSharedPointer< BaseSkewEstimationConfig >	config () const

Public Member Functions inherited from rdf::Module
	Module ()
	Default constructor Initializes a new instance of the Module class. More...

virtual QString	name () const
	Returns the module's name. More...

virtual void	setConfig (QSharedPointer< ModuleConfig > config)

QSharedPointer< ModuleConfig >	config () const

Protected Member Functions
cv::Mat	separability (const cv::Mat &srcImg, int w, int h, const cv::Mat &mask=cv::Mat())
	Computes the separability of two neighbouring regions based on mean and variance. More...

cv::Mat	edgeMap (const cv::Mat &separability, double thr, EdgeDirection direction=HORIZONTAL, const cv::Mat &mask=cv::Mat()) const
	Computes the edge map based on the separability More...

QVector< QVector3D >	computeWeights (cv::Mat edgeMap, int delta, int epsilon, EdgeDirection direction=HORIZONTAL)
	Computes the PPHT, detects straight lines and refines it More...

double	skewEst (const QVector< QVector3D > &weights, double imgDiagonal, bool &ok, double eta=0.35)
	Computes the skew based oon the detected lines More...

bool	checkInput () const override
	Checks the input - not yet implemented. More...

Protected Member Functions inherited from rdf::Module
QString	debugName () const

Protected Attributes
cv::Mat	mSrcImg

cv::Mat	mMask

Protected Attributes inherited from rdf::Module
QSharedPointer< ModuleConfig >	mConfig

Detailed Description

The class estimates the skew of a document page. The methodology is based on "Skew estimation of natural images based on a salient line detector", Hyung Il Koo and Nam Ik Cho

See also: Module

Member Enumeration Documentation

enum rdf::BaseSkewEstimation::EdgeDirection

Enumerator
HORIZONTAL
VERTICAL

Constructor & Destructor Documentation

rdf::BaseSkewEstimation::BaseSkewEstimation	(	const cv::Mat &	img = `cv::Mat()`,
		const cv::Mat &	mask = `cv::Mat()`
	)

Initializes a new instance of the BaseSkewEstimation class.

Parameters

img	The source img.
mask	The optional mask.

Member Function Documentation

bool rdf::BaseSkewEstimation::checkInput ( ) const

overrideprotectedvirtual

Checks the input - not yet implemented.

Returns

Implements rdf::Module.

bool rdf::BaseSkewEstimation::compute ( )

virtual

Computes the skew angle based on "Skew Estimation of natural images based on a salient line detector", Hyung Il Koo and Nam Ik Choo.

Returns: true if the angle could be computed

Implements rdf::Module.

QVector< QVector3D > rdf::BaseSkewEstimation::computeWeights	(	cv::Mat	edgeMap,
		int	delta,
		int	epsilon,
		EdgeDirection	direction = `HORIZONTAL`
	)

protected

Computes the PPHT, detects straight lines and refines it

Parameters

edgeMap	The edge map.
delta	Delta parameter: max coordinate deviation for refined lines.
epsilon	Epsilon parameter: max allowed deviation from line coordinates for the weight calculation (=2).
direction	The direction (horizontal or vertical).

Returns: The line weights

QSharedPointer< BaseSkewEstimationConfig > rdf::BaseSkewEstimation::config ( ) const

cv::Mat rdf::BaseSkewEstimation::edgeMap	(	const cv::Mat &	separability,
		double	thr,
		EdgeDirection	direction = `HORIZONTAL`,
		const cv::Mat &	mask = `cv::Mat()`
	)		const

protected

Computes the edge map based on the separability

Parameters

separability	The separability map.
thr	A threshold value for edges (=0.1).
direction	The direction (horizontal or vertical).
mask	The optional mask.

Returns: The edge map.

double rdf::BaseSkewEstimation::getAngle ( )

Gets the skew angle.

Returns: The skew angle

QVector< QVector4D > rdf::BaseSkewEstimation::getSelectedLines ( ) const

bool rdf::BaseSkewEstimation::isEmpty ( ) const

overridevirtual

Determines whether this instance is empty.

Returns: true if no src image is set.

Implements rdf::Module.

cv::Mat rdf::BaseSkewEstimation::separability	(	const cv::Mat &	srcImg,
		int	w,
		int	h,
		const cv::Mat &	mask = `cv::Mat()`
	)

protected

Computes the separability of two neighbouring regions based on mean and variance.

Parameters

srcImg	The source img.
w	The width of the region.
h	The height of the region.
mask	The optional mask.

Returns: The separability map

void rdf::BaseSkewEstimation::setFixedThr ( bool f )

void rdf::BaseSkewEstimation::setImages	(	const cv::Mat &	img,
		const cv::Mat &	mask = `cv::Mat()`
	)

Sets the images.

Parameters

img	The source img.
mask	The optional mask.

double rdf::BaseSkewEstimation::skewEst	(	const QVector< QVector3D > &	weights,
		double	imgDiagonal,
		bool &	ok,
		double	eta = `0.35`
	)

protected

Computes the skew based oon the detected lines

Parameters

weights	The weights.
imgDiagonal	The img diagonal.
ok	Ok - is set to false if only one line is detected.
eta	Eta - parameter to reject small lines.

Returns

QString rdf::BaseSkewEstimation::toString ( ) const

overridevirtual

Summarize the method as string. Not yet implemented.

Returns: Summary string.

Reimplemented from rdf::Module.

Member Data Documentation

cv::Mat rdf::BaseSkewEstimation::mMask

protected

cv::Mat rdf::BaseSkewEstimation::mSrcImg

protected

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

/srv/ReadFramework/src/Module/SkewEstimation.h
/srv/ReadFramework/src/Module/SkewEstimation.cpp

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation