Catalano.Imaging.Filters

Class OtsuThreshold

java.lang.Object

Catalano.Imaging.Filters.OtsuThreshold

All Implemented Interfaces:

IApplyInPlace

public class OtsuThreshold
extends java.lang.Object
implements IApplyInPlace

Otsu Threshold.
The class implements Otsu thresholding, which is described in N Otsu, "A threshold selection method from gray-level histograms", IEEE Trans. Systems, Man and Cybernetics 9(1), pp. 62–66, 1979.
This implementation instead of minimizing the weighted within-class variance does maximization of between-class variance, what gives the same result.

See Also:

MaximumEntropyThreshold, RosinThreshold

Constructor Summary

Constructors

Constructor and Description
OtsuThreshold() Initializes a new instance of the OtsuThreshold class.
OtsuThreshold(boolean invert) Initializes a new instance of the OtsuThreshold class.

Method Summary

Modifier and Type	Method and Description
void	applyInPlace(FastBitmap fastBitmap) Apply filter to an image.
int	CalculateThreshold(FastBitmap fastBitmap) Calculate binarization threshold for the given image.

Methods inherited from class java.lang.Object

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

Constructor Detail

OtsuThreshold

public OtsuThreshold()

Initializes a new instance of the OtsuThreshold class.

OtsuThreshold

public OtsuThreshold(boolean invert)

Initializes a new instance of the OtsuThreshold class.

Parameters:

invert - All pixels with intensities equal or higher than threshold value are converted to black pixels. All other pixels with intensities below threshold value are converted to white pixels.

Method Detail

applyInPlace

public void applyInPlace(FastBitmap fastBitmap)

Description copied from interface: IApplyInPlace

Apply filter to an image.

Specified by:

applyInPlace in interface IApplyInPlace

Parameters:

fastBitmap - Image to be processed.

CalculateThreshold

public int CalculateThreshold(FastBitmap fastBitmap)

Calculate binarization threshold for the given image.

Parameters:

fastBitmap - FastBitmap.

Returns:

Threshold value.