GammaCorrectionFilter (Strange Eons API)

java.lang.Object
- ca.cgjennings.graphics.filters.AbstractImageFilter
- - ca.cgjennings.graphics.filters.AbstractPixelwiseFilter
  - - ca.cgjennings.graphics.filters.GammaCorrectionFilter

All Implemented Interfaces:

java.awt.image.BufferedImageOp
```
public class GammaCorrectionFilter
extends AbstractPixelwiseFilter
```
Applies a gamma correction function to the source image. The alpha channel is unaffected. Gamma correction adjusts images to account for the property of the human visual system that it is more sensitive to the shadows in an image than it is to the highlights.
This filter can also be used to recolour an image by first converting it to greyscale and then applying a gamma correction in the direction of the desired colour. A gamma correction value of 1 results in no change to the affected channel; values greater than 1 increase the values in the channel and values less than 1 decrease the values in the channel and therefore also increase the relative amount of the channel's colour complement:
```
                      <1           1          >1
 Red gamma         More Cyan   No Change   More Red
 Green gamma    More Magenta   No Change   More Green
 Blue gamma      More Yellow   No Change   More Blue
 
```
For example, the following gamma correction values will approximate a sepia tone effect: R=1.5, G=1, B=0.5.
Since:

2.1

Author:

Chris Jennings

Constructor Summary

Constructors
Constructor	Description
`GammaCorrectionFilter()`
`GammaCorrectionFilter(double gamma)`
`GammaCorrectionFilter(double rGamma, double gGamma, double bGamma)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`static int[]`	`createGammaLookupTable(double gamma, int levels)`
`void`	`filterPixels(int[] argb, int start, int end)`	This method is called with a block of ARGB values to be filtered.
`double`	`getBlueGamma()`
`double`	`getGreenGamma()`
`double`	`getRedGamma()`
`void`	`setBlueGamma(double bGamma)`
`void`	`setGamma(double rGamma, double gGamma, double bGamma)`
`void`	`setGreenGamma(double gGamma)`
`void`	`setRedGamma(double rGamma)`

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

GammaCorrectionFilter
```
public GammaCorrectionFilter()
```

GammaCorrectionFilter

public GammaCorrectionFilter(double gamma)

GammaCorrectionFilter

public GammaCorrectionFilter(double rGamma,
                             double gGamma,
                             double bGamma)

Method Detail
- setGamma
```
public void setGamma(double rGamma,
                     double gGamma,
                     double bGamma)
```
- getRedGamma
```
public double getRedGamma()
```
- setRedGamma
```
public void setRedGamma(double rGamma)
```
- getGreenGamma
```
public double getGreenGamma()
```
- setGreenGamma
```
public void setGreenGamma(double gGamma)
```
- getBlueGamma
```
public double getBlueGamma()
```
- setBlueGamma
```
public void setBlueGamma(double bGamma)
```
- createGammaLookupTable
```
public static int[] createGammaLookupTable(double gamma,
                                           int levels)
```
- filterPixels
```
public void filterPixels(int[] argb,
                         int start,
                         int end)
```
  Description copied from class: AbstractPixelwiseFilter
  
  This method is called with a block of ARGB values to be filtered. Subclasses must override this method to implement the actual filtering algorithm by replacing each pixel value in the range argb[start] ... argb[end-1] with the filtered value.
  
  Specified by:
  
  filterPixels in class AbstractPixelwiseFilter
  
  Parameters:
  
  argb - an array of pixel data to filter
  
  start - the index of the first pixel to filter
  
  end - the index of the last pixel to filter, plus one