Package ca.cgjennings.graphics.filters

Class BrightnessContrastFilter

java.lang.Object

ca.cgjennings.graphics.filters.AbstractImageFilter

ca.cgjennings.graphics.filters.AbstractPixelwiseFilter

ca.cgjennings.graphics.filters.AbstractFunctionFilter

ca.cgjennings.graphics.filters.BrightnessContrastFilter

All Implemented Interfaces:

Fn, java.awt.image.BufferedImageOp

public class BrightnessContrastFilter
extends AbstractFunctionFilter

An image filter that adjusts the brightness and contrast of an image. The brightness and contrast adjustments are specified as values in the range -1 to +1 (inclusive). A value of 0 indicates no change, while values greater or less than 0 increase or decrease (respectively) the brightness or contrast.

In-place filtering: This class supports in-place filtering (the source and destination images may be the same).

Since:

3.0

Author:

Chris Jennings

Field Summary

Fields inherited from interface ca.cgjennings.math.Fn

IDENTITY

Constructor Summary

Constructors

Constructor	Description
BrightnessContrastFilter()	Creates a new filter with default brightness and contrast settings of 0, resulting in no change.
BrightnessContrastFilter(double brightness, double contrast)	Creates a new filter with the requested brightness and contrast adjustments.

Method Summary

Modifier and Type	Method	Description
double	f(double x)	A transfer function for the current brightness and contrast settings.
double	getBrightness()	Returns the current brightness adjustment setting, between -1 and 1 inclusive.
double	getContrast()	Returns the current contrast adjustment setting, between -1 and 1 inclusive.
void	setBrightness(double brightness)	Sets the current brightness adjustment setting, between -1 and 1 inclusive.
void	setContrast(double contrast)	Sets the current contrast adjustment setting, between -1 and 1 inclusive.

Methods inherited from class ca.cgjennings.graphics.filters.AbstractFunctionFilter

filterPixels, functionChanged

Methods inherited from class ca.cgjennings.graphics.filters.AbstractPixelwiseFilter

filter, filter, filterPixel, workFactor

Methods inherited from class ca.cgjennings.graphics.filters.AbstractImageFilter

clamp, clamp, clamp, clampBoth, createCompatibleDestImage, fA, fB, fG, fR, getARGB, getARGB, getARGBSynch, getBounds2D, getPoint2D, getRenderingHints, iA, iB, iG, iR, setARGB, setARGB, setARGBSynch

Methods inherited from class java.lang.Object

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

Constructor Detail

BrightnessContrastFilter

public BrightnessContrastFilter()

Creates a new filter with default brightness and contrast settings of 0, resulting in no change.

BrightnessContrastFilter

public BrightnessContrastFilter(double brightness,
                                double contrast)

Creates a new filter with the requested brightness and contrast adjustments.

Parameters:

brightness - the brightness adjustment factor to apply

contrast - the contrast adjustment factor to apply

Throws:

java.lang.IllegalArgumentException - if brightness or contrast are not in the range -1 to 1 inclusive

Method Detail

getBrightness

public double getBrightness()

Returns the current brightness adjustment setting, between -1 and 1 inclusive.

Returns:

the brightness adjustment setting

setBrightness

public void setBrightness(double brightness)

Sets the current brightness adjustment setting, between -1 and 1 inclusive. A value of 0 results in no brightness change, while negative and positive values decrease and increase brightness, respectively.

Parameters:

brightness - the brightness adjustment to apply to filtered images

getContrast

public double getContrast()

Returns the current contrast adjustment setting, between -1 and 1 inclusive.

Returns:

the contrast adjustment setting

setContrast

public void setContrast(double contrast)

Sets the current contrast adjustment setting, between -1 and 1 inclusive. A value of 0 results in no contrast change, while negative and positive values decrease and increase contrast, respectively.

Parameters:

contrast - the contrast adjustment to apply to filtered images

f

public double f(double x)

A transfer function for the current brightness and contrast settings. See AbstractFunctionFilter.f(double).

Specified by:

f in interface Fn

Specified by:

f in class AbstractFunctionFilter

Parameters:

x - the input value

Returns:

the output value after applying the brightness and contrast adjustment