Class BrightnessContrastFilter

java.lang.Object

java.awt.image.ImageFilter

java.awt.image.RGBImageFilter

com.twelvemonkeys.image.BrightnessContrastFilter

All Implemented Interfaces:

ImageConsumer, Cloneable

public class BrightnessContrastFilter
extends RGBImageFilter

Adjusts the contrast and brightness of an image.

For brightness, the valid range is -2.0,..,0.0,..,2.0. A value of 0.0 means no change. Negative values will make the pixels darker. Maximum negative value (-2) will make all filtered pixels black. Positive values will make the pixels brighter. Maximum positive value (2) will make all filtered pixels white.

For contrast, the valid range is -1.0,..,0.0,..,1.0. A value of 0.0 means no change. Negative values will reduce contrast. Maximum negative value (-1) will make all filtered pixels grey (no contrast). Positive values will increase contrast. Maximum positive value (1) will make all filtered pixels primary colors (either black, white, cyan, magenta, yellow, red, blue or green).

Version:

$Id: //depot/branches/personal/haraldk/twelvemonkeys/release-2/twelvemonkeys-core/src/main/java/com/twelvemonkeys/image/BrightnessContrastFilter.java#1 $

Field Summary

Fields

Modifier and Type	Field	Description
private final int[]	LUT

Fields inherited from class RGBImageFilter

canFilterIndexColorModel, newmodel, origmodel

Fields inherited from class ImageFilter

consumer

Fields inherited from interface ImageConsumer

COMPLETESCANLINES, IMAGEABORTED, IMAGEERROR, RANDOMPIXELORDER, SINGLEFRAME, SINGLEFRAMEDONE, SINGLEPASS, STATICIMAGEDONE, TOPDOWNLEFTRIGHT

Constructor Summary

Constructors

Constructor	Description
BrightnessContrastFilter()	Creates a BrightnessContrastFilter with default values (brightness=0.3, contrast=0.3).
BrightnessContrastFilter(float pBrightness, float pContrast)	Creates a BrightnessContrastFilter with the given values for brightness and contrast.

Method Summary

Modifier and Type	Method	Description
private static int	clamp(int i)
private static int[]	createLUT(float pBrightness, float pContrast)
int	filterRGB(int pX, int pY, int pARGB)	Filters one pixel, adjusting brightness and contrast according to this filter.

Methods inherited from class RGBImageFilter

filterIndexColorModel, filterRGBPixels, setColorModel, setPixels, setPixels, substituteColorModel

Methods inherited from class ImageFilter

clone, getFilterInstance, imageComplete, resendTopDownLeftRight, setDimensions, setHints, setProperties

Methods inherited from class Object

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

Field Details

LUT

private final int[] LUT

Constructor Details

BrightnessContrastFilter

public BrightnessContrastFilter()

Creates a BrightnessContrastFilter with default values (brightness=0.3, contrast=0.3).

This will slightly increase both brightness and contrast.

BrightnessContrastFilter

public BrightnessContrastFilter(float pBrightness,
 float pContrast)

Creates a BrightnessContrastFilter with the given values for brightness and contrast.

For brightness, the valid range is -2.0,..,0.0,..,2.0. A value of 0.0 means no change. Negative values will make the pixels darker. Maximum negative value (-2) will make all filtered pixels black. Positive values will make the pixels brighter. Maximum positive value (2) will make all filtered pixels white.

For contrast, the valid range is -1.0,..,0.0,..,1.0. A value of 0.0 means no change. Negative values will reduce contrast. Maximum negative value (-1) will make all filtered pixels grey (no contrast). Positive values will increase contrast. Maximum positive value (1) will make all filtered pixels primary colors (either black, white, cyan, magenta, yellow, red, blue or green).

Parameters:

pBrightness - adjust the brightness of the image, in the range -2.0,..,0.0,..,2.0.

pContrast - adjust the contrast of the image, in the range -1.0,..,0.0,..,1.0.

Method Details

createLUT

private static int[] createLUT(float pBrightness,
 float pContrast)

clamp

private static int clamp(int i)

filterRGB

public int filterRGB(int pX,
 int pY,
 int pARGB)

Filters one pixel, adjusting brightness and contrast according to this filter.

Specified by:

filterRGB in class RGBImageFilter

Parameters:

pX - x

pY - y

pARGB - pixel value in default color space

Returns:

the filtered pixel value in the default color space