Catalano.Imaging.Tools

Class DocumentSkewChecker

java.lang.Object

Catalano.Imaging.Tools.DocumentSkewChecker

public class DocumentSkewChecker
extends java.lang.Object

Skew angle checker for scanned documents.

Constructor Summary

Constructors

Constructor and Description
DocumentSkewChecker() Initializes a new instance of the DocumentSkewChecker class.

Method Summary

Modifier and Type	Method and Description
int	getLocalPeakRadius() Get local peak radius.
double	getMaxSkewToDetect() Get maximum skew angle to detect.
double	getSkewAngle(FastBitmap fastBitmap) Get skew angle of the provided document image.
int	getStepsPerDegree() Get steps per degree.
void	setLocalPeakRadius(int localPeakRadius) Radius for searching local peak value, [1, 10].
void	setMaxSkewToDetect(double maxSkewToDetect) Maximum skew angle to detect, [0, 45] degrees.
void	setStepsPerDegree(int stepsPerDegree) Set steps per degree, [1, 10].

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DocumentSkewChecker

public DocumentSkewChecker()

Initializes a new instance of the DocumentSkewChecker class.

Method Detail

getStepsPerDegree

public int getStepsPerDegree()

Get steps per degree.

Returns:

Steps per degree.

setStepsPerDegree

public void setStepsPerDegree(int stepsPerDegree)

Set steps per degree, [1, 10]. The value defines quality of Hough transform and its ability to detect line slope precisely. Default value is set to 1.

Parameters:

stepsPerDegree - Steps per degree.

getMaxSkewToDetect

public double getMaxSkewToDetect()

Get maximum skew angle to detect. Default value is set to 30.

Returns:

Maximum skew angle to detect.

setMaxSkewToDetect

public void setMaxSkewToDetect(double maxSkewToDetect)

Maximum skew angle to detect, [0, 45] degrees. The value sets maximum document's skew angle to detect. Document's skew angle can be as positive (rotated counter clockwise), as negative (rotated clockwise). So setting this value to 25, for example, will lead to [-25, 25] degrees detection range. Scanned documents usually have skew in the [-20, 20] degrees range.

Parameters:

maxSkewToDetect - Maximum skew to detect.

getLocalPeakRadius

public int getLocalPeakRadius()

Get local peak radius. Default value is set to 4.

Returns:

Local peak radius.

setLocalPeakRadius

public void setLocalPeakRadius(int localPeakRadius)

Radius for searching local peak value, [1, 10]. The value determines radius around a map's value, which is analyzed to determine if the map's value is a local maximum in specified area.

Parameters:

localPeakRadius - Local peak radius.

getSkewAngle

public double getSkewAngle(FastBitmap fastBitmap)

Get skew angle of the provided document image.

Parameters:

fastBitmap - FastBitmap.

Returns:

Returns document's skew angle. If the returned angle equals to -90, then document skew detection has failed.